An in vitro investigation of the retrograde flow fields of two bileaflet mechanical heart valves.

Science.gov (United States)

Ellis, J T; Healy, T M; Fontaine, A A; Weston, M W; Jarret, C A; Saxena, R; Yoganathan, A P

1996-11-01

Fluid stresses occurring in retrograde flow fields during valve closure may play a significant role in thrombogenesis. The squeeze flow and regurgitant jets can cause damage to formed blood elements due to high levels of turbulent shear stress. The aim of this study was to characterize in detail the spatial structure and temporal behavior of the retrograde flow fields of the St. Jude Medical and Medtronic Parallel bileaflet mechanical heart valves. Three-component, coincident laser Doppler anemometry (LDA) velocity measurements were obtained facilitating the determination of the full Reynolds stress tensor and the principal stresses in the valve flow fields. The experiments were performed in the Georgia Tech aortic flow chamber under physiologic pulsatile flow conditions. Data were collected over several hundred cardiac cycles for subsequent phase window averaging and generation of mean velocity and turbulence statistics over 20 ms intervals. A region approximately 8 mm x 10 mm was mapped 1.0 mm upstream of one hinge of each valve with an incremental resolution of 0.13-0.25 mm. Animation of the data allowed the visualization of the flow fields and a quantitative display of mean velocity and turbulent stress values. In the St. Jude Medical squeeze flow, the peak turbulent shear stress was 800 dynes/cm2 and the peak reverse velocity was 0.60 m/s. In the Medtronic Parallel squeeze flow, the peak turbulent shear stress was 1,000 dynes/cm2 and the peak velocity 0.70 m/s. The leakage jet fields of the two valves were very different: in the case of the St. Jude Medical valve, turbulent shear stresses reached 1,800 dynes/cm2 and peak jet velocity was 0.80 m/s; in the case of the Medtronic Parallel valve, turbulent shear stresses reached 3,690 dynes/cm2 and the peak jet velocity was 1.9 m/s. The retrograde flow fields of these two bileaflet mechanical heart valves appear to be design-dependent. The elevated turbulent shear stresses generated by both valve designs may

[11C]-Acetoacetate PET imaging: a potential early marker for cardiac heart failure

International Nuclear Information System (INIS)

Croteau, Etienne; Tremblay, Sébastien; Gascon, Suzanne; Dumulon-Perreault, Véronique; Labbé, Sébastien M.; Rousseau, Jacques A.; Cunnane, Stephen C.; Carpentier, André C.; Bénard, François; Lecomte, Roger

2014-01-01

The ketone body acetoacetate could be used as an alternate nutrient for the heart, and it also has the potential to improve cardiac function in an ischemic–reperfusion model or reduce the mitochondrial production of oxidative stress involved in cardiotoxicity. In this study, [ 11 C]-acetoacetate was investigated as an early marker of intracellular damage in heart failure. Methods: A rat cardiotoxicity heart failure model was induced by doxorubicin, Dox(+). [ 14 C]-Acetoacetate, a non-positron (β −) emitting radiotracer, was used to characterize the arterial blood input function and myocardial mitochondrial uptake. Afterward, [ 11 C]-acetoacetate (β +) myocardial PET images were obtained for kinetic analysis and heart function assessment in control Dox(−) (n = 15) and treated Dox(+) (n = 6) rats. The uptake rate (K 1 ) and myocardial clearance rate (k 2 or k mono ) were extracted. Results: [ 14 C]-Acetoacetate in the blood was increased in Dox(+), from 2 min post-injection until the last withdrawal point when the heart was harvested, as well as the uptake in the heart and myocardial mitochondria (unpaired t-test, p < 0.05). PET kinetic analysis of [ 11 C]-acetoacetate showed that rate constants K 1 , k 2 and k mono were decreased in Dox(+) (p < 0.05) combined with a reduction of 24% of the left ventricular ejection fraction (p < 0.001). Conclusion: Radioactive acetoacetate ex vivo analysis [ 14 C], and in vivo kinetic [ 11 C] studies provided evidence that [ 11 C]-acetoacetate can assess heart failure Dox(+). Contrary to myocardial flow reserve (rest–stress protocol), [ 11 C]-acetoacetate can be used to assess reduced kinetic rate constants without requirement of hyperemic stress response. The proposed [ 11 C]-acetoacetate cardiac radiotracer in the investigation of heart disease is novel and paves the way to a potential role for [ 11 C]-acetoacetate in cardiac pathophysiology

Angiotensin receptor-neprilysin inhibitors: clinical potential in heart failure and beyond

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Singh JSS

2015-06-01

Full Text Available Jagdeep SS Singh, Chim C Lang Division of Cardiovascular and Diabetes Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK Abstract: Heart failure remains a major concern across the globe as life expectancies and delivery of health care continue to improve. There has been a dearth of new developments in heart failure therapies in the last decade until last year, with the release of the results from the PARADIGM-HF Trial heralding the arrival of a promising new class of drug, ie, the angiotensin receptor-neprilysin inhibitor. In this review, we discuss the evolution of our incremental understanding of the neurohormonal mechanisms involved in the pathophysiology of heart failure, which has led to our success in modulating its various pathways. We start by examining the renin-angiotensin-aldosterone system, followed by the challenges of modulating the natriuretic peptide system. We then delve deeper into the pharmacology and mechanisms by which angiotensin receptor-neprilysin inhibitors achieve their significant cardiovascular benefits. Finally, we also consider the potential application of this new class of drug in other areas, such as heart failure with preserved ejection fraction, hypertension, patients with renal impairment, and following myocardial infarction. Keywords: heart failure, angiotensin receptor-neprilysin inhibitor, heart failure with preserved ejection fraction, nesiritide, candoxatril, omapatrilat, hypertension, renal impairment, myocardial infarction

Expression of Id2 in the Second Heart Field and Cardiac Defects in Id2 Knock-Out Mice

NARCIS (Netherlands)

Jongbloed, M. R. M.; Vicente-Steijn, R.; Douglas, Y. L.; Wisse, L. J.; Mori, K.; Yokota, Y.; Bartelings, M. M.; Schalij, M. J.; Mahtab, E. A.; Poelmann, R. E.; Gittenberger-De Groot, A. C.

2011-01-01

The inhibitor of differentiation Id2 is expressed in mesoderm of the second heart field, which contributes myocardial and mesenchymal cells to the primary heart tube. The role of Id2 in cardiac development is insufficiently known. Heart development was studied in sequential developmental stages in

Lung and heart dose volume analyses with CT simulator in tangential field irradiation of breast cancer

International Nuclear Information System (INIS)

Das, Indra J.; Cheng, Elizabeth C.; Fowble, Barbara

1997-01-01

Objective: Radiation pneumonitis and cardiac effects are directly related to the irradiated lung and heart volumes in the treatment fields. The central lung distance (CLD) from a tangential breast radiograph is shown to be a significant indicator of ipsilateral irradiated lung volume based on empirically derived functions which accuracy depends on the actual measured volume in treatment position. A simple and accurate linear relationship with CLD and retrospective analysis of the pattern of dose volume of lung and heart is presented with actual volume data from a CT simulator in the treatment of breast cancer. Materials and Methods: The heart and lung volumes in the tangential treatment fields were analyzed in 45 consecutive (22 left and 23 right breast) patients referred for CT simulation of the cone down treatment. All patients in this study were immobilized and placed on an inclined breast board in actual treatment setup. Both arms were stretched over head uniformly to avoid collision with the scanner aperture. Radiopaque marks were placed on the medial and lateral borders of the tangential fields. All patients were scanned in spiral mode with slice width and thickness of 3 mm each, respectively. The lung and heart structures as well as irradiated areas were delineated on each slice and respective volumes were accurately measured. The treatment beam parameters were recorded and the digitally reconstructed radiographs (DRRs) were generated for the CLD and analysis. Results: Table 1 shows the volume statistics of patients in this study. There is a large variation in the lung and heart volumes among patients. Due to differences in the shape of right and left lungs the percent irradiated volume (PIV) are different. The PIV data have shown to correlate with CLD with 2nd and 3rd degree polynomials; however, in this study a simple straight line regression is used to provide better confidence than the higher order polynomial. The regression lines for the left and right

Cyp26 Enzymes Facilitate Second Heart Field Progenitor Addition and Maintenance of Ventricular Integrity.

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Ariel B Rydeen

2016-11-01

Full Text Available Although retinoic acid (RA teratogenicity has been investigated for decades, the mechanisms underlying RA-induced outflow tract (OFT malformations are not understood. Here, we show zebrafish embryos deficient for Cyp26a1 and Cyp26c1 enzymes, which promote RA degradation, have OFT defects resulting from two mechanisms: first, a failure of second heart field (SHF progenitors to join the OFT, instead contributing to the pharyngeal arch arteries (PAAs, and second, a loss of first heart field (FHF ventricular cardiomyocytes due to disrupted cell polarity and extrusion from the heart tube. Molecularly, excess RA signaling negatively regulates fibroblast growth factor 8a (fgf8a expression and positively regulates matrix metalloproteinase 9 (mmp9 expression. Although restoring Fibroblast growth factor (FGF signaling can partially rescue SHF addition in Cyp26 deficient embryos, attenuating matrix metalloproteinase (MMP function can rescue both ventricular SHF addition and FHF integrity. These novel findings indicate a primary effect of RA-induced OFT defects is disruption of the extracellular environment, which compromises both SHF recruitment and FHF ventricular integrity.

Sympathetic Nervous Regulation of Calcium and Action Potential Alternans in the Intact Heart.

Science.gov (United States)

Winter, James; Bishop, Martin J; Wilder, Catherine D E; O'Shea, Christopher; Pavlovic, Davor; Shattock, Michael J

2018-01-01

Rationale: Arrhythmogenic cardiac alternans are thought to be an important determinant for the initiation of ventricular fibrillation. There is limited information on the effects of sympathetic nerve stimulation (SNS) on alternans in the intact heart and the conclusions of existing studies, focused on investigating electrical alternans, are conflicted. Meanwhile, several lines of evidence implicate instabilities in Ca handling, not electrical restitution, as the primary mechanism underpinning alternans. Despite this, there have been no studies on Ca alternans and SNS in the intact heart. The present study sought to address this, by application of voltage and Ca optical mapping for the simultaneous study of APD and Ca alternans in the intact guinea pig heart during direct SNS. Objective : To determine the effects of SNS on APD and Ca alternans in the intact guinea pig heart and to examine the mechanism(s) by which the effects of SNS are mediated. Methods and Results : Studies utilized simultaneous voltage and Ca optical mapping in isolated guinea pig hearts with intact innervation. Alternans were induced using a rapid dynamic pacing protocol. SNS was associated with rate-independent shortening of action potential duration (APD) and the suppression of APD and Ca alternans, as indicated by a shift in the alternans threshold to faster pacing rates. Qualitatively similar results were observed with exogenous noradrenaline perfusion. In contrast with previous reports, both SNS and noradrenaline acted to flatten the slope of the electrical restitution curve. Pharmacological block of the slow delayed rectifying potassium current (I Ks ), sufficient to abolish I Ks -mediated APD-adaptation, partially reversed the effects of SNS on pacing-induced alternans. Treatment with cyclopiazonic acid, an inhibitor of the sarco(endo)plasmic reticulum ATPase, had opposite effects to that of SNS, acting to increase susceptibility to alternans, and suggesting that accelerated Ca reuptake

Field Measurements Indicate Unexpected, Serious Underestimation of Mussel Heart Rates and Thermal Tolerance by Laboratory Studies.

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Morgana Tagliarolo

Full Text Available Attempts to predict the response of species to long-term environmental change are generally based on extrapolations from laboratory experiments that inevitably simplify the complex interacting effects that occur in the field. We recorded heart rates of two genetic lineages of the brown mussel Perna perna over a full tidal cycle in-situ at two different sites in order to evaluate the cardiac responses of the two genetic lineages present on the South African coast to temperature and the immersion/emersion cycle. "Robomussel" temperature loggers were used to monitor thermal conditions at the two sites over one year. Comparison with live animals showed that robomussels provided a good estimate of mussel body temperatures. A significant difference in estimated body temperatures was observed between the sites and the results showed that, under natural conditions, temperatures regularly approach or exceed the thermal limits of P. perna identified in the laboratory. The two P. perna lineages showed similar tidal and diel patterns of heart rate, with higher cardiac activity during daytime immersion and minimal values during daytime emersion. Comparison of the heart rates measured in the field with data previously measured in the laboratory indicates that laboratory results seriously underestimate heart rate activity, by as much as 75%, especially during immersion. Unexpectedly, field estimates of body temperatures indicated an ability to tolerate temperatures considered lethal on the basis of laboratory measurements. This suggests that the interaction of abiotic conditions in the field does not necessarily raise vulnerability to high temperatures.

Corrected body surface potential mapping.

Science.gov (United States)

Krenzke, Gerhard; Kindt, Carsten; Hetzer, Roland

2007-02-01

In the method for body surface potential mapping described here, the influence of thorax shape on measured ECG values is corrected. The distances of the ECG electrodes from the electrical heart midpoint are determined using a special device for ECG recording. These distances are used to correct the ECG values as if they had been measured on the surface of a sphere with a radius of 10 cm with its midpoint localized at the electrical heart midpoint. The equipotential lines of the electrical heart field are represented on the virtual surface of such a sphere. It is demonstrated that the character of a dipole field is better represented if the influence of the thorax shape is reduced. The site of the virtual reference electrode is also important for the dipole character of the representation of the electrical heart field.

A Role for the Cytoskeleton in Heart Looping

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Kersti K. Linask

2007-01-01

Full Text Available Over the past 10 years, key genes involved in specification of left-right laterality pathways in the embryo have been defined. The read-out for misexpression of laterality genes is usually the direction of heart looping. The question of how dextral looping direction occurred mechanistically and how the heart tube bends remains unknown. It is becoming clear from our experiments and those of others that left-right differences in cell proliferation in the second heart field (anterior heart field drives the dextral direction. Evidence is accumulating that the cytoskeleton is at the center of laterality, and the bending and rotational forces associated with heart looping. If laterality pathways are modulated upstream, the cytoskeleton, including nonmuscle myosin II (NMHC-II, is altered downstream within the cardiomyocytes, leading to looping abnormalities. The cytoskeleton is associated with important mechanosensing and signaling pathways in cell biology and development. The initiation of blood flow during the looping period and the inherent stresses associated with increasing volumes of blood flowing into the heart may help to potentiate the process. In recent years, the steps involved in this central and complex process of heart development that is the basis of numerous congenital heart defects are being unraveled.

Do mobile phones pose a potential risk to autonomic modulation of the heart?

Science.gov (United States)

Barutcu, Irfan; Esen, Ali Metin; Kaya, Dayimi; Turkmen, Muhsin; Karakaya, Osman; Saglam, Mustafa; Melek, Mehmet; Çelik, Ataç; Kilit, Celal; Onrat, Ersel; Kirma, Cevat

2011-11-01

It has long been speculated that mobile phones may interact with the cardiac devices and thereby cardiovascular system may be a potential target for the electromagnetic fields emitted by the mobile phones. Therefore, the present study was designed to test possible effects of radiofrequency waves emitted by digital mobile phones on cardiac autonomic modulation by short-time heart rate variability (HRV) analysis. A total of 20 healthy young subjects were included to the study. All participants were rested in supine position at least for 15 minutes on a comfortable bed, and then time and frequency domain HRV parameters were recorded at baseline in supine position for 5 minutes. After completion of baseline records, by using a mobile GSM (Global System for Mobile Communication) phone, HRV parameters were recorded at turned off mode, at turned on mode, and at calling mode over 5 minutes periods for each stage. Neither time nor frequency domain HRV parameters altered significantly during off mode compare to their baseline values. Also, neither time nor frequency domain HRV parameters altered significantly during turned on and calling mode compared to their baseline values. Short-time exposure to electromagnetic fields emitted by mobile phone does not affect cardiac autonomic modulation in healthy subjects.

Establishing the framework to support bioartificial heart fabrication using fibrin-based three-dimensional artificial heart muscle.

Science.gov (United States)

Hogan, Matthew; Mohamed, Mohamed; Tao, Ze-Wei; Gutierrez, Laura; Birla, Ravi

2015-02-01

Only 3000 heart transplants are performed in the USA every year, leaving some 30 000-70 000 Americans without proper care. Current treatment modalities for heart failure have saved many lives yet still do not correct the underlying problems of congestive heart failure. Tissue engineering represents a potential field of study wherein a combination of cells, scaffolds, and/or bioreactors can be utilized to create constructs to mimic, replace, and/or repair defective tissue. The focus of this study was to generate a bioartificial heart (BAH) model using artificial heart muscle (AHM), composed of fibrin gel and neonatal rat cardiac myocytes, and a decellularized scaffold, formed by subjecting an adult rat heart to a series of decellularization solutions. By suturing the AHM around the outside of the decellularized heart and culturing while suspended in media, we were able to retain functional cardiac cells on the scaffold as evinced by visible contractility. Observed contractility rate was correlated with biopotential measurements to confirm essential functionality of cardiac constructs. Cross-sections of the BAH show successful decellularization of the scaffold and contiguous cell-rich AHM around the perimeter of the heart. Copyright © 2014 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Implication of microRNAs in the development and potential treatment of radiation-induced heart disease.

Science.gov (United States)

Kura, Branislav; Babal, Pavel; Slezak, Jan

2017-10-01

Radiotherapy is the most commonly used methodology to treat oncological disease, one of the most widespread causes of death worldwide. Oncological patients cured by radiotherapy applied to the mediastinal area have been shown to suffer from cardiovascular disease. The increase in the prevalence of radiation-induced heart disease has emphasized the need to seek new therapeutic targets to mitigate the negative impact of radiation on the heart. In this regard, microRNAs (miRNAs) have received considerable interest. miRNAs regulate post-transcriptional gene expression by their ability to target various mRNA sequences because of their imperfect pairing with mRNAs. It has been recognized that miRNAs modulate a diverse spectrum of cardiac functions with developmental, pathophysiological, and clinical implications. This makes them promising potential targets for diagnosis and treatment. This review summarizes the recent findings about the possible involvement of miRNAs in radiation-induced heart disease and their potential use as diagnostic or treatment targets in this respect.

[Electric traction magnetic fields of ultra-low frequency as an occupational risk factor of ischemic heart disease].

Science.gov (United States)

Ptitsyna, N G; Kudrin, V A; Villorezi, D; Kopytenko, Iu A; Tiasto, M I; Kopytenko, E A; Bochko, V A; Iuchchi, N

1996-01-01

The study was inspired by earlier results that displayed influence of variable natural geomagnetic field (0.005-10 Hz range-ultra-low frequencies) on circulatory system, indicated possible correlation between industrial ultra-low frequency fields and prevalence of myocardial infarction. The authors conducted unique measurements of ultra-low frequency fields produced by electric engines. The results were compared with data on morbidity among railway transport workers. The findings are that level of magnetic variations in electric locomotive cabin can exceed 280 micro Tesla, whereas that in car sections reaches 50 micro Tesla. Occurrence of coronary heart disease among the locomotive operators appeared to be 2.0 + 0.2 times higher than that among the car section operators. Higher risk of coronary heart disease in the locomotive operators is associated with their increased occupational magnetic load.

Geft is dispensable for the development of the second heart field

Directory of Open Access Journals (Sweden)

Xiongwei Fan

2012-03-01

Full Text Available Geft is a guanine nucleotide exchange factor, which can specificallyactivate Rho family of small GTPase by catalyzing theexchange of bound GDP for GTP. Geft is highly expressed inthe excitable tissue as heart and skeletal muscle and plays importantroles in many cellular processes, such as cell proliferation,migration, and cell fate decision. However, the invivo role of Geft remains unknown. Here, we generated a Geftconditional knockout mouse by flanking exons 5-17 of Geftwith loxP sites. Cre-mediated deletion of the Geft gene in heartusing Mef2c-Cre transgenic mice resulted in a dramatic decreaseof Geft expression. Geft knockout mice develop normallyand exhibit no discernable phenotype, suggesting Geft isdispensable for the development of the second heart field inmouse. The Geft conditional knockout mouse will be a valuablegenetic tool for uncovering the in vivo roles of Geft duringdevelopment and in adult homeostasis. (BMB reports2012; 45(3: 153-158

Design and analysis of a field modulated magnetic screw for artificial heart

Science.gov (United States)

Ling, Zhijian; Ji, Jinghua; Wang, Fangqun; Bian, Fangfang

2017-05-01

This paper proposes a new electromechanical energy conversion system, called Field Modulated Magnetic Screw (FMMS) as a high force density linear actuator for artificial heart. This device is based on the concept of magnetic screw and linear magnetic gear. The proposed FMMS consists of three parts with the outer and inner carrying the radially magnetized helically permanent-magnet (PM), and the intermediate having a set of helically ferromagnetic pole pieces, which modulate the magnetic fields produced by the PMs. The configuration of the newly designed FMMS is presented and its electromagnetic performances are analyzed by using the finite-element analysis, verifying the advantages of the proposed structure.

Validation and potential mechanisms of red cell distribution width as a prognostic marker in heart failure.

Science.gov (United States)

Allen, Larry A; Felker, G Michael; Mehra, Mandeep R; Chiong, Jun R; Dunlap, Stephanie H; Ghali, Jalal K; Lenihan, Daniel J; Oren, Ron M; Wagoner, Lynne E; Schwartz, Todd A; Adams, Kirkwood F

2010-03-01

Adverse outcomes have recently been linked to elevated red cell distribution width (RDW) in heart failure. Our study sought to validate the prognostic value of RDW in heart failure and to explore the potential mechanisms underlying this association. Data from the Study of Anemia in a Heart Failure Population (STAMINA-HFP) registry, a prospective, multicenter cohort of ambulatory patients with heart failure supported multivariable modeling to assess relationships between RDW and outcomes. The association between RDW and iron metabolism, inflammation, and neurohormonal activation was studied in a separate cohort of heart failure patients from the United Investigators to Evaluate Heart Failure (UNITE-HF) Biomarker registry. RDW was independently predictive of outcome (for each 1% increase in RDW, hazard ratio for mortality 1.06, 95% CI 1.01-1.12; hazard ratio for hospitalization or mortality 1.06; 95% CI 1.02-1.10) after adjustment for other covariates. Increasing RDW correlated with decreasing hemoglobin, increasing interleukin-6, and impaired iron mobilization. Our results confirm previous observations that RDW is a strong, independent predictor of adverse outcome in chronic heart failure and suggest elevated RDW may indicate inflammatory stress and impaired iron mobilization. These findings encourage further research into the relationship between heart failure and the hematologic system. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Quantum particle in a potential well field and in an electric field

International Nuclear Information System (INIS)

Gyunter, U.; Olejnik, V.P.

1990-01-01

Solutions of the Dirac equation in the field of δ-like potential well with arbitrary symmetry and in uniform electric field were obtained and analyzed. It is shown that wave function and energy of electron in bound state in the absence of electric field depend sufficiently on the type of potential well symmetry. 1 ref

Practicing Reiki does not appear to routinely produce high-intensity electromagnetic fields from the heart or hands of Reiki practitioners.

Science.gov (United States)

Baldwin, Ann Linda; Rand, William Lee; Schwartz, Gary E

2013-06-01

The study objective was to determine whether Reiki practice increases the electromagnetic field strength from the heart and hands of Reiki practitioners. This study repeated experiments performed 20 years ago that detected exceptionally high-strength electromagnetic fields (100 nT) from the hands of several energy healers. The equipment used was far more sensitive than in the original studies. Using a Magnes 2500 WH SQUID, the electromagnetic field from the hands and heart of each of 3 Reiki masters was measured when they were (1) not practicing Reiki, (2) sending Reiki to a distant person, and (3) sending Reiki to a person in the room. Similar measurements were made on 4 Reiki-naïve volunteers before and after they received a Reiki training/attunement enabling them to self-administer Reiki. The study setting was the Scripps Institute, San Diego, CA. Magnetic field intensity of hands and heart recorded over 5-minute sessions with corresponding frequency spectra. For all subjects, under all conditions, sensors closest to the heart and the hands produced spikes of 2 pT corresponding to the heartbeat. Recordings from 2 Masters and 1 volunteer showed a low-intensity sine wave oscillation of 0.25-0.3 Hz (intensity 0.1-0.5 pT) whether or not they were practicing Reiki. This oscillation probably reflected respiratory sinus arrhythmia, judged by comparison with recent previous studies. These signals were not detected in the original studies. In the current study, no electromagnetic field intensities greater than 3 pT were observed in any of the recordings. Practicing Reiki does not appear to routinely produce high-intensity electromagnetic fields from the heart or hands. Alternatively, it is possible that energy healing is stimulated by tuning into an external environmental radiation, such as the Schumann resonance, which was blocked in the present study by the strong magnetic shielding surrounding the SQUID.

The helical ventricular myocardial band of Torrent-Guasp: potential implications in congenital heart defects.

Science.gov (United States)

Corno, Antonio F; Kocica, Mladen J; Torrent-Guasp, Francisco

2006-04-01

The new concepts of cardiac anatomy and physiology, based on the observations made by Francisco Torrent-Guasp's discovery of the helical ventricular myocardial band, can be useful in the context of the surgical strategies currently used to manage patients with congenital heart defects. The potential impact of the Torrent-Guasp's Heart on congenital heart defects have been analyzed in the following settings: ventriculo-arterial discordance (transposition of the great arteries), double (atrio-ventricular and ventriculo-arterial) discordance (congenitally corrected transposition of the great arteries), Ebstein's anomaly, pulmonary valve regurgitation after repair of tetralogy of Fallot, Ross operation, and complex intra-ventricular malformations. The functional interaction of right and left ventricles occurs not only through their arrangements in series but also thanks to the structural spiral features. Changes in size and function of either ventricle may influence the performance of the other ventricle. The variety and complexity of congenital heart defects make the recognition of the relationship between form and function a vital component, especially when compared to acquired disease. The new concepts of cardiac anatomy and function proposed by Francisco Torrent-Guasp, based on his observations, should stimulate further investigations of alternative surgical strategies by individuals involved with the management of patients with congenital heart defects.

Influence of low frequency magnetic field used in magnetotherapy on interleukin 6 (IL-6 contents in rat heart and brain

Directory of Open Access Journals (Sweden)

Elżbieta Ciejka

2017-08-01

Full Text Available Background: The human population is exposed ever more frequently to magnetic fields (MF. This is due to both technological progress and development of the economy as well as to advances made in medical science. That is why the thorough understanding and systematized knowledge about mechanisms by which MF exerts its effects on living organisms play such an important role. In this context the health of MF-exposed people is the subject of particular concern. The aim of the study was to evaluate the effect of extremely low frequency magnetic field (ELFMF used in magnetotherapy on the concentration of interleukin 6 (IL-6 in rat heart and brain. Material and Methods: The male rats were randomly divided into 3 experimental groups: group I – control, without contact with magnetic field; group II − exposed to bipolar, rectangular magnetic field 40 Hz, induction “peak-to-peak” 7 mT 30 min/day for 2 weeks; and group III − exposed to bipolar, rectangular magnetic field 40 Hz, 7 mT 60 min/day for 2 weeks. Concentration of IL-6 in the heart and brain of animals was measured after MF exposure. Results: Exposure to ELFMF: 40 Hz, induction “peak-to-peak” 7 mT 30 min/day for 2 weeks caused a significant IL-6 increase in rat hearts compared to the control group (p < 0.05 and a non-significant IL-6 decrease in rat brain. The magnetic field applied for 60 min resulted in non-significant IL-6 increase in rat hearts compared to the control group and significant IL-6 decrease in rat brain (p < 0.05. Conclusions: The influence of magnetic field on inflammation in the body varies depending on the MF parameters and the affected tissues or cells. Med Pr 2017;68(4:517–523

[Influence of low frequency magnetic field used in magnetotherapy on interleukin 6 (IL-6) contents in rat heart and brain].

Science.gov (United States)

Ciejka, Elżbieta; Skibska, Beata; Gorąca, Anna

2017-06-27

The human population is exposed ever more frequently to magnetic fields (MF). This is due to both technological progress and development of the economy as well as to advances made in medical science. That is why the thorough understanding and systematized knowledge about mechanisms by which MF exerts its effects on living organisms play such an important role. In this context the health of MF-exposed people is the subject of particular concern. The aim of the study was to evaluate the effect of extremely low frequency magnetic field (ELFMF) used in magnetotherapy on the concentration of interleukin 6 (IL-6) in rat heart and brain. The male rats were randomly divided into 3 experimental groups: group I - control, without contact with magnetic field; group II - exposed to bipolar, rectangular magnetic field 40 Hz, induction "peak-to-peak" 7 mT 30 min/day for 2 weeks; and group III - exposed to bipolar, rectangular magnetic field 40 Hz, 7 mT 60 min/day for 2 weeks. Concentration of IL-6 in the heart and brain of animals was measured after MF exposure. Exposure to ELFMF: 40 Hz, induction "peak-to-peak" 7 mT 30 min/day for 2 weeks caused a significant IL-6 increase in rat hearts compared to the control group (p < 0.05) and a non-significant IL-6 decrease in rat brain. The magnetic field applied for 60 min resulted in non-significant IL-6 increase in rat hearts compared to the control group and significant IL-6 decrease in rat brain (p < 0.05). The influence of magnetic field on inflammation in the body varies depending on the MF parameters and the affected tissues or cells. Med Pr 2017;68(4):517-523. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Potential of Field Education as Signature Pedagogy: The Field Director Role

Science.gov (United States)

Lyter, Sharon C.

2012-01-01

In light of the assertion that field education is the signature pedagogy of social work education, this Internet-based study explores field director demographics and questions the fulfillment of this potential, examining BSW and MSW field education through the lens of the field director position. Field directors (159) and deans/directors (150)…

Potentialities of radioisotope aniocardiography in diagnosis of acquired heart diseases

International Nuclear Information System (INIS)

Malov, G.A.; Mikaelyan, R.S.; Dumpe, A.N.

1980-01-01

On the base of the examination of 40 patients with acquired heart diseases and 5 people without heart diseases for control determined are the most charactreristic signs of the acquired heart disease of visual observation on RPP transit (albumin of human serum labelled by sup(99m)Tc) through the heart cavities and magistral vessels. It is shown that there is a close connection between central and intracardial hemodynamics which permjts to judge on the cardiac output on the base of mean circulation time (MCT). Radioisotopic angiocardiography permits to find redistribution of lung blood flow in patients with acquired heart diseases, which can serve as indirect index of long hypertension

High-resolution measurement of the unsteady velocity field to evaluate blood damage induced by a mechanical heart valve.

Science.gov (United States)

Bellofiore, Alessandro; Quinlan, Nathan J

2011-09-01

We investigate the potential of prosthetic heart valves to generate abnormal flow and stress patterns, which can contribute to platelet activation and lysis according to blood damage accumulation mechanisms. High-resolution velocity measurements of the unsteady flow field, obtained with a standard particle image velocimetry system and a scaled-up model valve, are used to estimate the shear stresses arising downstream of the valve, accounting for flow features at scales less than one order of magnitude larger than blood cells. Velocity data at effective spatial and temporal resolution of 60 μm and 1.75 kHz, respectively, enabled accurate extraction of Lagrangian trajectories and loading histories experienced by blood cells. Non-physiological stresses up to 10 Pa were detected, while the development of vortex flow in the wake of the valve was observed to significantly increase the exposure time, favouring platelet activation. The loading histories, combined with empirical models for blood damage, reveal that platelet activation and lysis are promoted at different stages of the heart cycle. Shear stress and blood damage estimates are shown to be sensitive to measurement resolution.

The effective crystal field potential

CERN Document Server

Mulak, J

2000-01-01

As it results from the very nature of things, the spherical symmetry of the surrounding of a site in a crystal lattice or an atom in a molecule can never occur. Therefore, the eigenfunctions and eigenvalues of any bound ion or atom have to differ from those of spherically symmetric respective free ions. In this way, the most simplified concept of the crystal field effect or ligand field effect in the case of individual molecules can be introduced. The conventional notion of the crystal field potential is narrowed to its non-spherical part only through ignoring the dominating spherical part which produces only a uniform energy shift of gravity centres of the free ion terms. It is well understood that the non-spherical part of the effective potential "seen" by open-shell electrons localized on a metal ion plays an essential role in most observed properties. Light adsorption, electron paramagnetic resonance, inelastic neutron scattering and basic characteristics derived from magnetic and thermal measurements, ar...

Microelectrode array measurement of potassium ion channel remodeling on the field action potential duration in rapid atrial pacing rabbits model.

Science.gov (United States)

Sun, Juan; Yan, Huang; Wugeti, Najina; Guo, Yujun; Zhang, Ling; Ma, Mei; Guo, Xingui; Jiao, Changan; Xu, Wenli; Li, Tianqi

2015-01-01

Atrial fibrillation (AF) arises from abnormalities in atrial structure and electrical activity. Microelectrode arrays (MEA) is a real-time, nondestructive measurement of the resting and action potential signal, from myocardial cells, to the peripheral circuit of electrophysiological activity. This study examined the field action potential duration (fAPD) of the right atrial appendage (RAA) by MEA in rapid atrial pacing (RAP) in the right atrium of rabbits. In addition, this study also investigated the effect of potassium ion channel blockers on fAPD. 40 New Zealand white rabbits of either sex were randomly divided into 3 groups: 1) the control, 2) potassium ion channel blocker (TEA, 4-Ap and BaCl2), and 3) amiodarone groups. The hearts were quickly removed and right atrial appendage sectioned (slice thickness 500 μm). Each slice was perfused with Tyrode's solution and continuously stimulated for 30 minutes. Sections from the control group were superfused with Tyrode's solution for 10 minutes, while the blocker groups and amiodarone were both treated with their respective compounds for 10 minutes each. The fAPD of RAA and action field action potential morphology were measured using MEA. In non-pace (control) groups, fAPD was 188.33 ± 18.29 ms after Tyrode's solution superfusion, and 173.91 ± 6.83 ms after RAP. In pace/potassium ion channel groups, TEA and BaCl2 superfusion prolonged atrial field action potential (fAPD) (control vs blocker: 176.67 ± 8.66 ms vs 196.11 ± 10.76 ms, 182.22 ± 12.87 ms vs 191.11 ± 13.09 ms with TEA and BaCl2 superfusion, respectively, P action potential in animal heart slices. After superfusing potassium ion channel blockers, fAPD was prolonged. These results suggest that Ito, IKur and IK1 remodel and mediate RAP-induced atrial electrical remodeling. Amiodarone alter potassium ion channel activity (Ito, IKur, IK1 and IKs), shortening fAPD.

Non-potential Field Formation in the X-shaped Quadrupole Magnetic Field Configuration

Energy Technology Data Exchange (ETDEWEB)

Kawabata, Y.; Shimizu, T. [Department of Earth and Planetary Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Inoue, S., E-mail: kawabata.yusuke@ac.jaxa.jp [Max-Planck-Institute for Solar System Research, Justus-von-Liebig-Weg 3 D-37077 Göttingen (Germany)

2017-06-20

Some types of solar flares are observed in X-shaped quadrupolar field configuration. To understand the magnetic energy storage in such a region, we studied non-potential field formation in an X-shaped quadrupolar field region formed in the active region NOAA 11967, which produced three X-shaped M-class flares on 2014 February 2. Nonlinear force-free field modeling was applied to a time series of vector magnetic field maps from the Solar Optical Telescope on board Hinode and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory . Our analysis of the temporal three-dimensional magnetic field evolution shows that the sufficient free energy had already been stored more than 10 hr before the occurrence of the first M-class flare and that the storage was observed in a localized region. In this localized region, quasi-separatrix layers (QSLs) started to develop gradually from 9 hr before the first M-class flare. One of the flare ribbons that appeared in the first M-class flare was co-spatial with the location of the QSLs, suggesting that the formation of the QSLs is important in the process of energy release. These QSLs do not appear in the potential field calculation, indicating that they were created by the non-potential field. The formation of the QSLs was associated with the transverse photospheric motion of the pre-emerged flux and the emergence of a new flux. This observation indicates that the occurrence of the flares requires the formation of QSLs in the non-potential field in which free magnetic energy is stored in advance.

Heart transplantation in adults with congenital heart disease.

Science.gov (United States)

Houyel, Lucile; To-Dumortier, Ngoc-Tram; Lepers, Yannick; Petit, Jérôme; Roussin, Régine; Ly, Mohamed; Lebret, Emmanuel; Fadel, Elie; Hörer, Jürgen; Hascoët, Sébastien

2017-05-01

With the advances in congenital cardiac surgery and postoperative care, an increasing number of children with complex congenital heart disease now reach adulthood. There are already more adults than children living with a congenital heart defect, including patients with complex congenital heart defects. Among these adults with congenital heart disease, a significant number will develop ventricular dysfunction over time. Heart failure accounts for 26-42% of deaths in adults with congenital heart defects. Heart transplantation, or heart-lung transplantation in Eisenmenger syndrome, then becomes the ultimate therapeutic possibility for these patients. This population is deemed to be at high risk of mortality after heart transplantation, although their long-term survival is similar to that of patients transplanted for other reasons. Indeed, heart transplantation in adults with congenital heart disease is often challenging, because of several potential problems: complex cardiac and vascular anatomy, multiple previous palliative and corrective surgeries, and effects on other organs (kidney, liver, lungs) of long-standing cardiac dysfunction or cyanosis, with frequent elevation of pulmonary vascular resistance. In this review, we focus on the specific problems relating to heart and heart-lung transplantation in this population, revisit the indications/contraindications, and update the long-term outcomes. Copyright © 2017. Published by Elsevier Masson SAS.

Brain-heart interactions: challenges and opportunities with functional magnetic resonance imaging at ultra-high field.

Science.gov (United States)

Chang, Catie; Raven, Erika P; Duyn, Jeff H

2016-05-13

Magnetic resonance imaging (MRI) at ultra-high field (UHF) strengths (7 T and above) offers unique opportunities for studying the human brain with increased spatial resolution, contrast and sensitivity. However, its reliability can be compromised by factors such as head motion, image distortion and non-neural fluctuations of the functional MRI signal. The objective of this review is to provide a critical discussion of the advantages and trade-offs associated with UHF imaging, focusing on the application to studying brain-heart interactions. We describe how UHF MRI may provide contrast and resolution benefits for measuring neural activity of regions involved in the control and mediation of autonomic processes, and in delineating such regions based on anatomical MRI contrast. Limitations arising from confounding signals are discussed, including challenges with distinguishing non-neural physiological effects from the neural signals of interest that reflect cardiorespiratory function. We also consider how recently developed data analysis techniques may be applied to high-field imaging data to uncover novel information about brain-heart interactions. © 2016 The Author(s).

Potential of resveratrol in the treatment of heart failure.

Science.gov (United States)

Raj, Pema; Louis, Xavier Lieben; Thandapilly, Sijo Joseph; Movahed, Ali; Zieroth, Shelley; Netticadan, Thomas

2014-01-30

The concept of food has expanded beyond its traditional role of survival and hunger satisfaction, to include a role in the prevention and treatment of disease. Polyphenols are classes of compounds that are synthesized by plants to serve a wide variety of functions including growth pollination and defense. These compounds have recently received increased attention in medical research. In this group, one of the most studied has been resveratrol (3,5,4,-trihydroxystilbene), a polyphenol, which is found predominantly in grapes and berries. Over the past two decades, researchers have studied the ability of resveratrol to prevent or reverse the development of abnormalities in heart structure and function in animal models of heart disease and heart failure. The results from animal studies have been promising, and very recently, this knowledge has been translated into examining the efficacy of resveratrol in humans with heart disease/failure. In this review we will discuss the current status of resveratrol research on cardioprotection. Copyright © 2013 Elsevier Inc. All rights reserved.

The anti-calcification potential of a silsesquioxane nanocomposite polymer under in vitro conditions: potential material for synthetic leaflet heart valve.

Science.gov (United States)

Ghanbari, Hossein; Kidane, Asmeret G; Burriesci, Gaetano; Ramesh, Bala; Darbyshire, Arnold; Seifalian, Alexander M

2010-11-01

Calcification currently represents a major cause of failure of biological tissue heart valves. It is a complex phenomenon influenced by a number of biochemical and mechanical factors. Recent advances in material science offer new polymers with improved properties, potentially suitable for synthetic leaflets heart valves manufacturing. In this study, the calcification-resistance efficacy and mechanical and surface properties of a new nanocomposite polymeric material (polyhedral oligomeric silsesquioxane-poly(carbonate-urea)urethane; POSS-PCU) which has been developed by our group are assessed by means of in vitro testing. In particular, thin sheets of nanocomposite, glutaraldehyde-fixed bovine pericardium (BP) and polyurethane (PU) were exposed to a calcium solution into a specially designed in vitro accelerated physiological pulsatile pressure system for a period of 31days and a total of 4×10(7) cycles. The samples were investigated for signs of calcification after exposure to calcium solution by means of X-ray, microscopic and chemical inspections. Mechanical and surface properties were also studied using stress-strain behaviour and surface morphology and hydrophobicity. Comparison shows that, in the experimental conditions, the level of calcification for the nanocomposite is considerably lower than for the fixed BP (p=0.008) and PU samples (p=0.015). Also, mechanical properties were unchanged in POSS-PCU, while there was a significant deterioration in PU samples (pnanocomposite remained more hydrophobic than the PU sample (pnanocomposite in synthetic leaflets heart valves may lead to potential advantages in terms of long-term performances and durability. Copyright © 2010. Published by Elsevier Ltd.

Biodistribution of radioactive organocations and cationic technetium complexes - implications to the uptake mechanism of potential heart-affine radiopharmaceuticals

International Nuclear Information System (INIS)

Muenze, R.; Shyre, R.; Seifert, S.; Guethert, I.; Kretschmar, M.; Kampf, G.; Knop, G.; Mohnike, W.; Schmidt, J.

1986-01-01

The biodistribution of various 14 C labeled organocations (ammonium, phosphonium) and cationic technetium complexes (TcCl 2 DMPE 2 ,TcDMPE 3 + ) was studied in rats to find potential relations between the chemical composition, structure, molecular size, lipophilicity and heart uptake. All of the radioactive cations were distributed in a similar manner, but with different biokinetics. Molecules containing several electronegative atoms in their ligand structure, e.g. nitrogen or oxygen which enhance polarity, were rapidly accumulated, but washed out again with resultant transient and diminished heart uptake. More highly lipophilic materials, by contrast, showed more extensive accumulation and persistent retention in the heart. The effect of human serum albumin on heart uptake was studied in a perfused heart model. Strong albumin binding prevented extensive heart uptake. This undesirable effect was neutralized by adding detergents to the perfusion bath. Evidence from these animal experiments was considered in the development of a new heart-seeking technetium compound (Tc-DPO), which is characterized by rapid accumulation in the human heart and substantially delayed washout. Heart images with minimal overlap of the inferoposterior wall and the right liver lobe were available in no more than 10 minutes p.i. in both planar and SPECT modes. A deficit in the inferior region was much more clearly defined than on the corresponding Thallium image. (Author)

Magnetic resonance imaging of congenital heart disease at 0.3 T

International Nuclear Information System (INIS)

Malmgren, N.

1995-11-01

The aim of this study was to systematically evaluate the potential of static MR imaging in congenital heart disease. The diagnosis of vascular rings, causing significant respiratory morbidity, previously required invasive methods for diagnosis. In aberrant left pulmonary artery, an uncommon anomaly, MR imaging at 0.3 T provided complete anatomic information. Complex congenital heart malformation is a diagnostic challenge. MR imaging at 0.3 T was efficient in defining most of the components of complex disease. It is especially valuable for imaging of extracardiac structures, which can be difficult to evaluate using echocardiography. MR imaging is an important complement to echocardiography. Improved equipment with sophisticated dynamic applications using high magnetic field strength is now available. The anatomical evaluation of congenital heart anomalies is however still based on static images, and low field magnets will certainly be used even in the future. 141 refs, 11 figs, 8 tabs

Magnetic resonance imaging of congenital heart disease at 0.3 T

Energy Technology Data Exchange (ETDEWEB)

Malmgren, N

1995-11-01

The aim of this study was to systematically evaluate the potential of static MR imaging in congenital heart disease. The diagnosis of vascular rings, causing significant respiratory morbidity, previously required invasive methods for diagnosis. In aberrant left pulmonary artery, an uncommon anomaly, MR imaging at 0.3 T provided complete anatomic information. Complex congenital heart malformation is a diagnostic challenge. MR imaging at 0.3 T was efficient in defining most of the components of complex disease. It is especially valuable for imaging of extracardiac structures, which can be difficult to evaluate using echocardiography. MR imaging is an important complement to echocardiography. Improved equipment with sophisticated dynamic applications using high magnetic field strength is now available. The anatomical evaluation of congenital heart anomalies is however still based on static images, and low field magnets will certainly be used even in the future. 141 refs, 11 figs, 8 tabs.

The localization of focal heart activity via body surface potential measurements: tests in a heterogeneous torso phantom

International Nuclear Information System (INIS)

Wetterling, F; Liehr, M; Haueisen, J; Schimpf, P; Liu, H

2009-01-01

The non-invasive localization of focal heart activity via body surface potential measurements (BSPM) could greatly benefit the understanding and treatment of arrhythmic heart diseases. However, the in vivo validation of source localization algorithms is rather difficult with currently available measurement techniques. In this study, we used a physical torso phantom composed of different conductive compartments and seven dipoles, which were placed in the anatomical position of the human heart in order to assess the performance of the Recursively Applied and Projected Multiple Signal Classification (RAP-MUSIC) algorithm. Electric potentials were measured on the torso surface for single dipoles with and without further uncorrelated or correlated dipole activity. The localization error averaged 11 ± 5 mm over 22 dipoles, which shows the ability of RAP-MUSIC to distinguish an uncorrelated dipole from surrounding sources activity. For the first time, real computational modelling errors could be included within the validation procedure due to the physically modelled heterogeneities. In conclusion, the introduced heterogeneous torso phantom can be used to validate state-of-the-art algorithms under nearly realistic measurement conditions.

The localization of focal heart activity via body surface potential measurements: tests in a heterogeneous torso phantom

Science.gov (United States)

Wetterling, F.; Liehr, M.; Schimpf, P.; Liu, H.; Haueisen, J.

2009-09-01

The non-invasive localization of focal heart activity via body surface potential measurements (BSPM) could greatly benefit the understanding and treatment of arrhythmic heart diseases. However, the in vivo validation of source localization algorithms is rather difficult with currently available measurement techniques. In this study, we used a physical torso phantom composed of different conductive compartments and seven dipoles, which were placed in the anatomical position of the human heart in order to assess the performance of the Recursively Applied and Projected Multiple Signal Classification (RAP-MUSIC) algorithm. Electric potentials were measured on the torso surface for single dipoles with and without further uncorrelated or correlated dipole activity. The localization error averaged 11 ± 5 mm over 22 dipoles, which shows the ability of RAP-MUSIC to distinguish an uncorrelated dipole from surrounding sources activity. For the first time, real computational modelling errors could be included within the validation procedure due to the physically modelled heterogeneities. In conclusion, the introduced heterogeneous torso phantom can be used to validate state-of-the-art algorithms under nearly realistic measurement conditions.

Dynamic Artificial Potential Fields for Autonomous Camera Control

DEFF Research Database (Denmark)

Burelli, Paolo; Jhala, Arnav Harish

2009-01-01

the implementation and evaluation of Artificial Potential Fields for automatic camera placement. We first describe the re- casting of the frame composition problem as a solution to a two particles suspended in an Artificial Potential Field. We demonstrate the application of this technique to control both camera...

The canonical way to make a heart: β-catenin and plakoglobin in heart development and remodeling.

Science.gov (United States)

Piven, Oksana O; Winata, Cecilia L

2017-12-01

The main mediator of the canonical Wnt pathway, β-catenin, is a major effector of embryonic development, postnatal tissue homeostasis, and adult tissue regeneration. The requirement for β-catenin in cardiogenesis and embryogenesis has been well established. However, many questions regarding the molecular mechanisms by which β-catenin and canonical Wnt signaling regulate these developmental processes remain unanswered. An interesting question that emerged from our studies concerns how β-catenin signaling is modulated through interaction with other factors. Recent experimental data implicate new players in canonical Wnt signaling, particularly those which modulate β-catenin function in many its biological processes, including cardiogenesis. One of the interesting candidates is plakoglobin, a little-studied member of the catenin family which shares several mechanistic and functional features with its close relative, β-catenin. Here we have focused on the function of β-catenin in cardiogenesis. We also summarize findings on plakoglobin signaling function and discuss possible interplays between β-catenin and plakoglobin in the regulation of embryonic heart development. Impact statement Heart development, function, and remodeling are complex processes orchestrated by multiple signaling networks. This review examines our current knowledge of the role of canonical Wnt signaling in cardiogenesis and heart remodeling, focusing primarily on the mechanistic action of its effector β-catenin. We summarize the generally accepted understanding of the field based on experimental in vitro and in vivo data, and address unresolved questions in the field, specifically relating to the role of canonical Wnt signaling in heart maturation and regeneration. What are the modulators of canonical Wnt, and particularly what are the potential roles of plakoglobin, a close relative of β-catenin, in regulating Wnt signaling?Answers to these questions will enhance our understanding of the

Dual-well potential field function for articulated manipulator trajectory planning

Directory of Open Access Journals (Sweden)

Ahmed Badawy

2016-06-01

Full Text Available A new attractive potential field function is proposed in this paper for manipulator trajectory planning. Existing attractive potential field constructs a global minimum through which maneuvering objects move down the gradient of the potential field toward this global minimum. The proposed method constructs a potential field with two minima. The purpose of these two minima is to create a dual attraction between links rather than affecting each link by the preceding one through kinematic constraints.

Isl1 expression at the venous pole identifies a novel role for the second heart field in cardiac development.

Science.gov (United States)

Snarr, Brian S; O'Neal, Jessica L; Chintalapudi, Mastan R; Wirrig, Elaine E; Phelps, Aimee L; Kubalak, Steven W; Wessels, Andy

2007-11-09

The right ventricle and outflow tract of the developing heart are derived from mesodermal progenitor cells from the second heart field (SHF). SHF cells have been characterized by expression of the transcription factor Islet-1 (Isl1). Although Isl1 expression has also been reported in the venous pole, the specific contribution of the SHF to this part of the heart is unknown. Here we show that Isl1 is strongly expressed in the dorsal mesenchymal protrusion (DMP), a non-endocardially-derived mesenchymal structure involved in atrioventricular septation. We further demonstrate that abnormal development of the SHF-derived DMP is associated with the pathogenesis of atrioventricular septal defects. These results identify a novel role for the SHF.

Generation of iPSC from cardiac and tail-tip fibroblasts derived from a second heart field reporter mouse.

Science.gov (United States)

Linares, Javier; Arellano-Viera, Estibaliz; Iglesias-García, Olalla; Ferreira, Carmen; Iglesias, Elena; Abizanda, Gloria; Prósper, Felipe; Carvajal-Vergara, Xonia

2016-05-01

Mef2c Anterior Heart Field (AHF) enhancer is activated during embryonic heart development and it is expressed in multipotent cardiovascular progenitors (CVP) giving rise to endothelial and myocardial components of the outflow tract, right ventricle and ventricular septum. Here we have generated iPSC from transgenic Mef2c-AHF-Cre x Ai6(RCLZsGreen) mice. These iPSC will provide a novel tool to investigate the AHF-CVP and their cell progeny. Copyright © 2016 Roslin Cells Ltd. Published by Elsevier B.V. All rights reserved.

Analytical formulation for φ4 field potential dynamics

International Nuclear Information System (INIS)

Javidan, Kurosh; Ghahraman, Arash

2011-01-01

An analytical model for adding a space dependent potential to the φ 4 field equation of motion is presented, by constructing a collective coordinate system for the solitary solutions of this model. The interaction of φ 4 solitons with a delta function potential barrier and also delta function potential well is investigated. Most of the characters of interaction are derived analytically while they are calculated by other models numerically. We will find that the behaviour of a solitary solution is like a point particle which is moved under the influence of a complicated effective potential. The effective potential is a function of the field initial conditions and also of parameters of the added potential. (author)

State-of-the-art implantable cardiac assist device therapy for heart failure: bridge to transplant and destination therapy.

Science.gov (United States)

Park, S J; Kushwaha, S S; McGregor, C G A

2012-01-01

Congestive heart failure is associated with poor quality of life (QoL) and low survival rates. The development of state-of-the-art cardiac devices holds promise for improved therapy in patients with heart failure. The field of implantable cardiac assist devices is changing rapidly with the emergence of continuous-flow pumps (CFPs). The important developments in this field, including pertinent clinical trials, registry reports, innovative research, and potential future directions are discussed in this paper.

Self-constrained inversion of potential fields

Science.gov (United States)

Paoletti, V.; Ialongo, S.; Florio, G.; Fedi, M.; Cella, F.

2013-11-01

We present a potential-field-constrained inversion procedure based on a priori information derived exclusively from the analysis of the gravity and magnetic data (self-constrained inversion). The procedure is designed to be applied to underdetermined problems and involves scenarios where the source distribution can be assumed to be of simple character. To set up effective constraints, we first estimate through the analysis of the gravity or magnetic field some or all of the following source parameters: the source depth-to-the-top, the structural index, the horizontal position of the source body edges and their dip. The second step is incorporating the information related to these constraints in the objective function as depth and spatial weighting functions. We show, through 2-D and 3-D synthetic and real data examples, that potential field-based constraints, for example, structural index, source boundaries and others, are usually enough to obtain substantial improvement in the density and magnetization models.

Noncontact measurement of electrostatic fields: Verification of modeled potentials within ion mobility spectrometer drift tube designs

International Nuclear Information System (INIS)

Scott, Jill R.; Tremblay, Paul L.

2007-01-01

The heart of an ion mobility spectrometer is the drift region where ion separation occurs. While the electrostatic potentials within a drift tube design can be modeled, no method for independently validating the electrostatic field has previously been reported. Two basic drift tube designs were modeled using SIMION 7.0 to reveal the expected electrostatic fields: (1) A traditional alternating set of electrodes and insulators and (2) a truly linear drift tube. One version of the alternating electrode/insulator drift tube and two versions of linear drift tubes were then fabricated. The stacked alternating electrodes/insulators were connected through a resistor network to generate the electrostatic gradient in the drift tube. The two linear drift tube designs consisted of two types of resistive drift tubes with one tube consisting of a resistive coating within an insulating tube and the other tube composed of resistive ferrites. The electrostatic fields within each type of drift tube were then evaluated by a noncontact method using a Kelvin-Zisman type electrostatic voltmeter and probe (results for alternative measurement methods provided in supplementary material). The experimental results were then compared with the electrostatic fields predicted by SIMION. Both the modeling and experimental measurements reveal that the electrostatic fields within a stacked ion mobility spectrometer drift tube are only pseudo-linear, while the electrostatic fields within a resistive drift tube approach perfect linearity

'Shovel-Ready' applications of stem cell advances for pediatric heart disease.

Science.gov (United States)

Files, Matthew D; Boucek, Robert J

2012-10-01

The past decade has seen remarkable advances in the field of stem cell biology. Many new technologies and applications are passing the translational phase and likely will soon be relevant for the clinical pediatric cardiologist. This review will focus on two advances in basic science that are now translating into clinical trials. The first advance is the recognition, characterization, and recent therapeutic application of resident cardiac progenitor cells (CPCs). Early results of adult trials and scattered case reports in pediatric patients support expanding CPC-based trials for end-stage heart failure in pediatric patients. The relative abundance of CPCs in the neonate and young child offers greater potential benefits in heart failure treatment than has been realized to date. The second advance is the technology of induced pluripotent stem cells (iPSCs), which reprograms differentiated somatic cells to an undifferentiated embryonic-like state. When iPSCs are differentiated into cardiomyocytes, they model a patient's specific disease, test pharmaceuticals, and potentially provide an autologous source for cell-based therapy. The therapeutic recruitment and/or replacement of CPCs has potential for enhancing cardiac repair and regeneration in children with heart failure. Use of iPSCs to model heart disease holds great potential to gain new insights into diagnosis, pathophysiology, and disease-specific management for genetic-based cardiovascular diseases that are prevalent in pediatric patients.

Heart regeneration.

Science.gov (United States)

Breckwoldt, Kaja; Weinberger, Florian; Eschenhagen, Thomas

2016-07-01

Regenerating an injured heart holds great promise for millions of patients suffering from heart diseases. Since the human heart has very limited regenerative capacity, this is a challenging task. Numerous strategies aiming to improve heart function have been developed. In this review we focus on approaches intending to replace damaged heart muscle by new cardiomyocytes. Different strategies for the production of cardiomyocytes from human embryonic stem cells or human induced pluripotent stem cells, by direct reprogramming and induction of cardiomyocyte proliferation are discussed regarding their therapeutic potential and respective advantages and disadvantages. Furthermore, different methods for the transplantation of pluripotent stem cell-derived cardiomyocytes are described and their clinical perspectives are discussed. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel. Copyright © 2015 Elsevier B.V. All rights reserved.

Potential problems with interpolating fields

Energy Technology Data Exchange (ETDEWEB)

Birse, Michael C. [The University of Manchester, Theoretical Physics Division, School of Physics and Astronomy, Manchester (United Kingdom)

2017-11-15

A potential can have features that do not reflect the dynamics of the system it describes but rather arise from the choice of interpolating fields used to define it. This is illustrated using a toy model of scattering with two coupled channels. A Bethe-Salpeter amplitude is constructed which is a mixture of the waves in the two channels. The potential derived from this has a strong repulsive core, which arises from the admixture of the closed channel in the wave function and not from the dynamics of the model. (orig.)

Expression of the BMP receptor Alk3 in the second heart field is essential for development of the dorsal mesenchymal protrusion and atrioventricular septation

NARCIS (Netherlands)

Briggs, Laura E.; Phelps, Aimee L.; Brown, Elizabeth; Kakarla, Jayant; Anderson, Robert H.; van den Hoff, Maurice J. B.; Wessels, Andy

2013-01-01

The dorsal mesenchymal protrusion (DMP) is a prong of mesenchyme derived from the second heart field (SHF) located at the venous pole of the developing heart. Recent studies have shown that perturbation of its development is associated with the pathogenesis of atrioventricular (AV) septal defect.

Electric Potential and Electric Field Imaging with Applications

Science.gov (United States)

Generazio, Ed

2016-01-01

The technology and techniques for remote quantitative imaging of electrostatic potentials and electrostatic fields in and around objects and in free space is presented. Electric field imaging (EFI) technology may be applied to characterize intrinsic or existing electric potentials and electric fields, or an externally generated electrostatic field may be used for (illuminating) volumes to be inspected with EFI. The baseline sensor technology, electric field sensor (e-sensor), and its construction, optional electric field generation (quasistatic generator), and current e-sensor enhancements (ephemeral e-sensor) are discussed. Demonstrations for structural, electronic, human, and memory applications are shown. This new EFI capability is demonstrated to reveal characterization of electric charge distribution, creating a new field of study that embraces areas of interest including electrostatic discharge mitigation, crime scene forensics, design and materials selection for advanced sensors, dielectric morphology of structures, inspection of containers, inspection for hidden objects, tether integrity, organic molecular memory, and medical diagnostic and treatment efficacy applications such as cardiac polarization wave propagation and electromyography imaging.

Hydroxychloroquine reduces heart rate by modulating the hyperpolarization-activated current If: Novel electrophysiological insights and therapeutic potential

Science.gov (United States)

Capel, Rebecca A.; Herring, Neil; Kalla, Manish; Yavari, Arash; Mirams, Gary R.; Douglas, Gillian; Bub, Gil; Channon, Keith; Paterson, David J.; Terrar, Derek A.; Burton, Rebecca-Ann B.

2015-01-01

Background Bradycardic agents are of interest for the treatment of ischemic heart disease and heart failure, as heart rate is an important determinant of myocardial oxygen consumption. Objectives The purpose of this study was to investigate the propensity of hydroxychloroquine (HCQ) to cause bradycardia. Methods We assessed the effects of HCQ on (1) cardiac beating rate in vitro (mice); (2) the “funny” current (If) in isolated guinea pig sinoatrial node (SAN) myocytes (1, 3, 10 µM); (3) heart rate and blood pressure in vivo by acute bolus injection (rat, dose range 1–30 mg/kg), (4) blood pressure and ventricular function during feeding (mouse, 100 mg/kg/d for 2 wk, tail cuff plethysmography, anesthetized echocardiography). Results In mouse atria, spontaneous beating rate was significantly (P < .05) reduced (by 9% ± 3% and 15% ± 2% at 3 and 10 µM HCQ, n = 7). In guinea pig isolated SAN cells, HCQ conferred a significant reduction in spontaneous action potential firing rate (17% ± 6%, 1 μM dose) and a dose-dependent reduction in If (13% ± 3% at 1 µM; 19% ± 2% at 3 µM). Effects were also observed on L-type calcium ion current (ICaL) (12% ± 4% reduction) and rapid delayed rectifier potassium current (IKr) (35% ± 4%) at 3 µM. Intravenous HCQ decreased heart rate in anesthetized rats (14.3% ± 1.1% at 15mg/kg; n = 6) without significantly reducing mean arterial blood pressure. In vivo feeding studies in mice showed no significant change in systolic blood pressure nor left ventricular function. Conclusions We have shown that HCQ acts as a bradycardic agent in SAN cells, in atrial preparations, and in vivo. HCQ slows the rate of spontaneous action potential firing in the SAN through multichannel inhibition, including that of If. PMID:26025323

Reduced intrinsic heart rate is associated with reduced arrhythmic susceptibility in guinea-pig heart.

Science.gov (United States)

Osadchii, Oleg E

2014-12-01

In the clinical setting, patients with slower resting heart rate are less prone to cardiovascular death compared with those with elevated heart rate. However, electrophysiological adaptations associated with reduced cardiac rhythm have not been thoroughly explored. In this study, relationships between intrinsic heart rate and arrhythmic susceptibility were examined by assessments of action potential duration (APD) rate adaptation and inducibility of repolarization alternans in sinoatrial node (SAN)-driven and atrioventricular (AV)-blocked guinea-pig hearts perfused with Langendorff apparatus. Electrocardiograms, epicardial monophasic action potentials, and effective refractory periods (ERP) were assessed in normokalemic and hypokalemic conditions. Slower basal heart rate in AV-blocked hearts was associated with prolonged ventricular repolarization during spontaneous beating, and with attenuated APD shortening at increased cardiac activation rates during dynamic pacing, when compared with SAN-driven hearts. During hypokalemic perfusion, the inducibility of repolarization alternans and tachyarrhythmia by rapid pacing was found to be lower in AV-blocked hearts. This difference was ascribed to prolonged ERP in the setting of reduced basal heart rate, which prevented ventricular capture at critically short pacing intervals required to induce arrhythmia. Reduced basal heart rate is associated with electrophysiological changes that prevent electrical instability upon an abrupt cardiac acceleration.

Genetics of common forms of heart failure: challenges and potential solutions.

Science.gov (United States)

Rau, Christoph D; Lusis, Aldons J; Wang, Yibin

2015-05-01

In contrast to many other human diseases, the use of genome-wide association studies (GWAS) to identify genes for heart failure (HF) has had limited success. We will discuss the underlying challenges as well as potential new approaches to understanding the genetics of common forms of HF. Recent research using intermediate phenotypes, more detailed and quantitative stratification of HF symptoms, founder populations and novel animal models has begun to allow researchers to make headway toward explaining the genetics underlying HF using GWAS techniques. By expanding analyses of HF to improved clinical traits, additional HF classifications and innovative model systems, the intractability of human HF GWAS should be ameliorated significantly.

[Genetics of congenital heart diseases].

Science.gov (United States)

Bonnet, Damien

2017-06-01

Developmental genetics of congenital heart diseases has evolved from analysis of serial slices in embryos towards molecular genetics of cardiac morphogenesis with a dynamic view of cardiac development. Genetics of congenital heart diseases has also changed from formal genetic analysis of familial recurrences or population-based analysis to screening for mutations in candidates genes identified in animal models. Close cooperation between molecular embryologists, pathologists involved in heart development and pediatric cardiologists is crucial for further increase of knowledge in the field of cardiac morphogenesis and genetics of cardiac defects. The genetic model for congenital heart disease has to be revised to favor a polygenic origin rather than a monogenic one. The main mechanism is altered genic dosage that can account for heart diseases in chromosomal anomalies as well as in point mutations in syndromic and isolated congenital heart diseases. The use of big data grouping information from cardiac development, interactions between genes and proteins, epigenetic factors such as chromatin remodeling or DNA methylation is the current source for improving our knowledge in the field and to give clues for future therapies. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Cardiac development : the posterior heart field and atrioventricular reentry tachycardia

NARCIS (Netherlands)

Hahurij, Nathan Dominggus

2011-01-01

This thesis is separated in two parts (Part I and Part II) in which normal and abnormal heart development are studied and related to congenital heart disease, in particular to the etiology of supraventricular arrhythmias in fetuses and neonates. Part I describes the development of the posterior

Effective potentials for twisted fields

International Nuclear Information System (INIS)

Banach, R.

1981-01-01

Minus the density of the effective action, evaluated at the lowest eigenfunction of the (space-time) derivative part of the second (functional) derivative of the classical action, is proposed as a generalised definition of the effective potential, applicable to twisted as well as untwisted sectors of a field theory. The proposal is corroborated by several specific calculations in the twisted sector, namely phi 4 theory (real and complex) and wrong-sign-Gordon theory, in an Einstein cylinder, where the exact integrability of the static solutions confirms the effective potential predictions. Both models exhibit a phase transition, which the effective potential locates, and the one-loop quantum shift in the critical radius is computed for the real phi 4 model, being a universal result. Topological mass generation at the classical level is pointed out, and the exactness of the classical effective potential approximation for complex phi 4 is discussed. (author)

Magnetic fields, special relativity and potential theory elementary electromagnetic theory

CERN Document Server

Chirgwin, B H; Kilmister, C W

1972-01-01

Magnetic Fields, Special Relativity and Potential Theory is an introduction to electromagnetism, special relativity, and potential theory, with emphasis on the magnetic field of steady currents (magnetostatics). Topics covered range from the origin of the magnetic field and the magnetostatic scalar potential to magnetization, electromagnetic induction and magnetic energy, and the displacement current and Maxwell's equations. This volume is comprised of five chapters and begins with an overview of magnetostatics, followed by a chapter on the methods of solving potential problems drawn from elec

Acquired heart conditions in adults with congenital heart disease: a growing problem.

Science.gov (United States)

Tutarel, Oktay

2014-09-01

The number of adults with congenital heart disease is increasing due to the great achievements in the field of paediatric cardiology, congenital heart surgery and intensive care medicine over the last decades. Mortality has shifted away from the infant and childhood period towards adulthood. As congenital heart disease patients get older, a high prevalence of cardiovascular risk factors is encountered similar to the general population. Consequently, the contribution of acquired morbidities, especially acquired heart conditions to patient outcome, is becoming increasingly important. Therefore, to continue the success story of the last decades in the treatment of congenital heart disease and to further improve the outcome of these patients, more attention has to be given to the prevention, detection and adequate therapy of acquired heart conditions. The aim of this review is to give an overview about acquired heart conditions that may be encountered in adults with congenital heart disease. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Glycosylated Chromogranin A: Potential Role in the Pathogenesis of Heart Failure.

Science.gov (United States)

Ottesen, Anett H; Christensen, Geir; Omland, Torbjørn; Røsjø, Helge

2017-12-01

Endocrine and paracrine factors influence the cardiovascular system and the heart by a number of different mechanisms. The chromogranin-secretogranin (granin) proteins seem to represent a new family of proteins that exerts both direct and indirect effects on cardiac and vascular functions. The granin proteins are produced in multiple tissues, including cardiac cells, and circulating granin protein concentrations provide incremental prognostic information to established risk indices in patients with myocardial dysfunction. In this review, we provide recent data for the granin proteins in relation with cardiovascular disease, and with a special focus on chromogranin A and heart failure. Chromogranin A is the most studied member of the granin protein family, and shorter, functionally active peptide fragments of chromogranin A exert protective effects on myocardial cell death, ischemia-reperfusion injury, and cardiomyocyte Ca 2+ handling. Granin peptides have also been found to induce angiogenesis and vasculogenesis. Protein glycosylation is an important post-translational regulatory mechanism, and we recently found chromogranin A molecules to be hyperglycosylated in the failing myocardium. Chromogranin A hyperglycosylation impaired processing of full-length chromogranin A molecules into physiologically active chromogranin A peptides, and patients with acute heart failure and low rate of chromogranin A processing had increased mortality compared to other acute heart failure patients. Other studies have also demonstrated that circulating granin protein concentrations increase in parallel with heart failure disease stage. The granin protein family seems to influence heart failure pathophysiology, and chromogranin A hyperglycosylation could directly be implicated in heart failure disease progression.

Pharmacological characterization of Tc-99m(CN-t-butyl)/sub 6//sup +/: A potential heart agent

International Nuclear Information System (INIS)

Pendleton, D.B.; Delano, M.L.; Sands, H.; Gallagher, B.M.; Liteplo, M.P.; Camin, L.L.; Subramanyam, V.

1984-01-01

The authors have investigated the pharmacological behavior of hexakis (t-butylisonitrile)Tc(I) and evaluated it as a potential myocardial perfusion radiopharmaceutical. This complex produces good to excellent heart images in rats, guinea pigs, rabbits, cats, dogs, pigs and baboons. Good heart uptake in guinea pigs, cats and pigs may be predictive of good myocardial imaging in man, since the hearts of these three species extract Tl-201, but not Tc-99m(dmpe)/sub 2/-Cl/sub 2//sup +/ (similar to man, but unlike other animal species). Biodistribution studies reveal initial heart uptake of 1.3 to 2.2% of the injected activity. Imaging and biodistribution show significant initial lung activity which clears substantially during the first hour after injection. Little or no myocardial washout is observed. In rabbits with ischemia induced by coronary artery ligation, the complex distributes as a function of blood flow. Simultaneous injection of Tl-201 and Tc-99m (CN-t-butyl)/sub 6//sup +/ with subsequent dual isotope imaging shows that their initial distribution is a similar. The complex is extracted 100% by isolated rabbit and guinea pig hearts perfused with buffer. When human blood is mixed and co-injected with the complex, myocardial extraction is reduced, but remains high (73-75%). Uptake of the complex by rat myocytes in culture is not inhibited by either ouabain or K/sup +/. These results suggest that this complex may be a promising myocardial perfusion agent and should be tested in man

A regularization method for extrapolation of solar potential magnetic fields

Science.gov (United States)

Gary, G. A.; Musielak, Z. E.

1992-01-01

The mathematical basis of a Tikhonov regularization method for extrapolating the chromospheric-coronal magnetic field using photospheric vector magnetograms is discussed. The basic techniques show that the Cauchy initial value problem can be formulated for potential magnetic fields. The potential field analysis considers a set of linear, elliptic partial differential equations. It is found that, by introducing an appropriate smoothing of the initial data of the Cauchy potential problem, an approximate Fourier integral solution is found, and an upper bound to the error in the solution is derived. This specific regularization technique, which is a function of magnetograph measurement sensitivities, provides a method to extrapolate the potential magnetic field above an active region into the chromosphere and low corona.

Filament shape versus coronal potential magnetic field structure

Science.gov (United States)

Filippov, B.

2016-01-01

Solar filament shape in projection on disc depends on the structure of the coronal magnetic field. We calculate the position of polarity inversion lines (PILs) of coronal potential magnetic field at different heights above the photosphere, which compose the magnetic neutral surface, and compare with them the distribution of the filament material in Hα chromospheric images. We found that the most of the filament material is enclosed between two PILs, one at a lower height close to the chromosphere and one at a higher level, which can be considered as a height of the filament spine. Observations of the same filament on the limb by the Solar Terrestrial Relations Observatory spacecraft confirm that the height of the spine is really very close to the value obtained from the PIL and filament border matching. Such matching can be used for filament height estimations in on-disc observations. Filament barbs are housed within protruding sections of the low-level PIL. On the base of simple model, we show that the similarity of the neutral surfaces in potential and non-potential fields with the same sub-photospheric sources is the reason for the found tendency for the filament material to gather near the potential-field neutral surface.

Vitamin D and Heart Failure.

Science.gov (United States)

Marshall Brinkley, D; Ali, Omair M; Zalawadiya, Sandip K; Wang, Thomas J

2017-10-01

Vitamin D is principally known for its role in calcium homeostasis, but preclinical studies implicate multiple pathways through which vitamin D may affect cardiovascular function and influence risk for heart failure. Many adults with cardiovascular disease have low vitamin D status, making it a potential therapeutic target. We review the rationale and potential role of vitamin D supplementation in the prevention and treatment of chronic heart failure. Substantial observational evidence has associated low vitamin D status with the risk of heart failure, ventricular remodeling, and clinical outcomes in heart failure, including mortality. However, trials assessing the influence of vitamin D supplementation on surrogate markers and clinical outcomes in heart failure have generally been small and inconclusive. There are insufficient data to recommend routine assessment or supplementation of vitamin D for the prevention or treatment of chronic heart failure. Prospective trials powered for clinical outcomes are warranted.

The potential influence of atherogenic dyslipidemia on the severity of chronic Chagas heart disease

Directory of Open Access Journals (Sweden)

Luz Peverengo

2016-02-01

Full Text Available SUMMARY Introduction: chronic Chagas heart disease (CCHD is the most common manifestation of American Trypanosomiasis, causing about 50,000 deaths annually. Several factors bear correlation with the severity of CCHD. However, to our knowledge, the assessment on the contribution of major cardiovascular risk factors (CRF, such as hypertension and atherogenic dyslipidemia (AD to CCHD severity is scarce, despite their well-established role in coronary artery disease, heart failure and stroke. Objective: to explore the potential relationship of blood pressure and AD with the clinical profile of patients with CCHD. Methods: we performed a cross-sectional study in T. cruziseropositive patients categorized according to a standard CCHD classification. All individuals were subjected to complete clinical examination. Autoantibodies induced by T. cruzi were assessed by ELISA. Results: we observed that Atherogenic index (AI levels rose significantly in relation to the severity of the CCHD stage, with CCHD III cases showing the highest values of AI. Furthermore, those patients with globally dilated cardiomyopathy with reduced ejection fraction showed higher levels of AI. In regard to autoantibodies, anti-B13 also showed relation with the severity of the disease. Conclusion: we observed that AI correlated with CCHD stages and contributed, in association with anti-B13 antibodies and age, to the prediction of systolic heart failure.

Action potential propagation: ion current or intramembrane electric field?

Science.gov (United States)

Martí, Albert; Pérez, Juan J; Madrenas, Jordi

2018-01-01

The established action potential propagation mechanisms do not satisfactorily explain propagation on myelinated axons given the current knowledge of biological channels and membranes. The flow across ion channels presents two possible effects: the electric potential variations across the lipid bilayers (action potential) and the propagation of an electric field through the membrane inner part. The proposed mechanism is based on intra-membrane electric field propagation, this propagation can explain the action potential saltatory propagation and its constant delay independent of distance between Ranvier nodes in myelinated axons.

CORONAL MAGNETIC FIELDS DERIVED FROM SIMULTANEOUS MICROWAVE AND EUV OBSERVATIONS AND COMPARISON WITH THE POTENTIAL FIELD MODEL

Energy Technology Data Exchange (ETDEWEB)

Miyawaki, Shun; Nozawa, Satoshi [Department of Science, Ibaraki University, Mito, Ibaraki 310-8512 (Japan); Iwai, Kazumasa; Shibasaki, Kiyoto [Nobeyama Solar Radio Observatory, National Astronomical Observatory of Japan, Minamimaki, Nagano 384-1305 (Japan); Shiota, Daikou, E-mail: shunmi089@gmail.com [Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya, Aichi 464-8601 (Japan)

2016-02-10

We estimated the accuracy of coronal magnetic fields derived from radio observations by comparing them to potential field calculations and the differential emission measure measurements using EUV observations. We derived line-of-sight components of the coronal magnetic field from polarization observations of the thermal bremsstrahlung in the NOAA active region 11150, observed around 3:00 UT on 2011 February 3 using the Nobeyama Radioheliograph at 17 GHz. Because the thermal bremsstrahlung intensity at 17 GHz includes both chromospheric and coronal components, we extracted only the coronal component by measuring the coronal emission measure in EUV observations. In addition, we derived only the radio polarization component of the corona by selecting the region of coronal loops and weak magnetic field strength in the chromosphere along the line of sight. The upper limits of the coronal longitudinal magnetic fields were determined as 100–210 G. We also calculated the coronal longitudinal magnetic fields from the potential field extrapolation using the photospheric magnetic field obtained from the Helioseismic and Magnetic Imager. However, the calculated potential fields were certainly smaller than the observed coronal longitudinal magnetic field. This discrepancy between the potential and the observed magnetic field strengths can be explained consistently by two reasons: (1) the underestimation of the coronal emission measure resulting from the limitation of the temperature range of the EUV observations, and (2) the underestimation of the coronal magnetic field resulting from the potential field assumption.

Chamber identity programs drive early functional partitioning of the heart.

Science.gov (United States)

Mosimann, Christian; Panáková, Daniela; Werdich, Andreas A; Musso, Gabriel; Burger, Alexa; Lawson, Katy L; Carr, Logan A; Nevis, Kathleen R; Sabeh, M Khaled; Zhou, Yi; Davidson, Alan J; DiBiase, Anthony; Burns, Caroline E; Burns, C Geoffrey; MacRae, Calum A; Zon, Leonard I

2015-08-26

The vertebrate heart muscle (myocardium) develops from the first heart field (FHF) and expands by adding second heart field (SHF) cells. While both lineages exist already in teleosts, the primordial contributions of FHF and SHF to heart structure and function remain incompletely understood. Here we delineate the functional contribution of the FHF and SHF to the zebrafish heart using the cis-regulatory elements of the draculin (drl) gene. The drl reporters initially delineate the lateral plate mesoderm, including heart progenitors. Subsequent myocardial drl reporter expression restricts to FHF descendants. We harnessed this unique feature to uncover that loss of tbx5a and pitx2 affect relative FHF versus SHF contributions to the heart. High-resolution physiology reveals distinctive electrical properties of each heart field territory that define a functional boundary within the single zebrafish ventricle. Our data establish that the transcriptional program driving cardiac septation regulates physiologic ventricle partitioning, which successively provides mechanical advantages of sequential contraction.

Photospheric Driving of Non-Potential Coronal Magnetic Field Simulations

Science.gov (United States)

2016-09-19

synthesize observable emission . In future, the computational speed of the MF model makes it a potential avenue for near- real time and/or ensemble...AFRL-AFOSR-UK-TR-2016-0030 PHOTOSPHERIC DRIVING OF NON-POTENTIAL CORONAL MAGNETIC FIELD SIMULATIONS Anthony Yeates UNIVERSITY OF DURHAM Final Report...Final 3. DATES COVERED (From - To)  15 Sep 2014 to 14 Sep 2017 4. TITLE AND SUBTITLE PHOTOSPHERIC DRIVING OF NON-POTENTIAL CORONAL MAGNETIC FIELD

Pulmonary Vein, Dorsal Atrial Wall and Atrial Septum Abnormalities in Podoplanin Knockout Mice With Disturbed Posterior Heart Field Contribution

NARCIS (Netherlands)

Douglas, Yvonne L.; Mahtab, Edris A. F.; Jongbloed, Monique R. M.; Uhrin, Pavel; Zaujec, Jan; Binder, Bernd R.; Schalij, Martin J.; Poelmann, Robert E.; Deruiter, Marco C.; Gittenberger-De Groot, Adriana C.

The developing sinus venosus myocardium, derived from the posterior heart field, contributes to the atrial septum, the posterior atrial wall, the sino-atrial node, and myocardium lining the pulmonary and cardinal veins, all expressing podoplanin, a coelomic and myocardial marker. . We compared

"The Heart Game"

DEFF Research Database (Denmark)

Dithmer, Marcus; Rasmussen, Jack Ord; Grönvall, Erik

2016-01-01

Objective: The aim of this article is to describe the development and testing of a prototype application (“The Heart Game”) using gamification principles to assist heart patients in their telerehabilitation process in the Teledialog project. Materials and Methods: A prototype game was developed via...... (interviews, participant observations, focus group interviews, and workshop) was used. Interviews with three healthcare professionals and 10 patients were carried out over a period of 2 weeks in order to evaluate the use of the prototype. Results: The heart patients reported the application to be a useful...... activities. Conclusions: “The Heart Game” concept presents a new way to motivate heart patients by using technology as a social and active approach to telerehabilitation. The findings show the potential of using gamification for heart patients as part of a telerehabilitation program. The evaluation indicated...

Technetium SPECT agents for imaging heart and brain

International Nuclear Information System (INIS)

Linder, K.E.

1990-01-01

One major goal of radiopharmaceutical research has been the development of technetium-based perfusion tracers for SPECT imaging of the heart and brain. The recent clinical introduction of the technetium complexes HM-PAO, ECD and DMG-2MP for brain imaging, and of CDO-MEB and MIBI for heart imaging promises to revolutionize the field of nuclear medicine. All of these agents appear to localize in the target tissue in proportion to blood flow, but their mechanisms of localization and/or retention may differ quite widely. In this talk, a survey of the new technetium SPECT agents will be presented. The inorganic and biological chemistry of these complexes, mechanisms of uptake and retention, QSAR studies, and potential clinical applications are discussed

Ventricular filling slows epicardial conduction and increases action potential duration in an optical mapping study of the isolated rabbit heart

Science.gov (United States)

Sung, Derrick; Mills, Robert W.; Schettler, Jan; Narayan, Sanjiv M.; Omens, Jeffrey H.; McCulloch, Andrew D.; McCullough, A. D. (Principal Investigator)

2003-01-01

INTRODUCTION: Mechanical stimulation can induce electrophysiologic changes in cardiac myocytes, but how mechanoelectric feedback in the intact heart affects action potential propagation remains unclear. METHODS AND RESULTS: Changes in action potential propagation and repolarization with increased left ventricular end-diastolic pressure from 0 to 30 mmHg were investigated using optical mapping in isolated perfused rabbit hearts. With respect to 0 mmHg, epicardial strain at 30 mmHg in the anterior left ventricle averaged 0.040 +/- 0.004 in the muscle fiber direction and 0.032 +/- 0.006 in the cross-fiber direction. An increase in ventricular loading increased average epicardial activation time by 25%+/- 3% (P action potential duration at 20% repolarization (APD20) but did at 80% repolarization (APD80), from 179 +/- 7 msec to 207 +/- 5 msec (P action potential duration by a load-dependent mechanism that may not involve stretch-activated channels.

Influenza infection and heart failure-vaccination may change heart failure prognosis?

Science.gov (United States)

Kadoglou, Nikolaos P E; Bracke, Frank; Simmers, Tim; Tsiodras, Sotirios; Parissis, John

2017-05-01

The interaction of influenza infection with the pathogenesis of acute heart failure (AHF) and the worsening of chronic heart failure (CHF) is rather complex. The deleterious effects of influenza infection on AHF/CHF can be attenuated by specific immunization. Our review aimed to summarize the efficacy, effectiveness, safety, and dosage of anti-influenza vaccination in HF. In this literature review, we searched MEDLINE and EMBASE from January 1st 1966 to December 31st, 2016, for studies examining the association between AHF/CHF, influenza infections, and anti-influenza immunizations. We used broad criteria to increase the sensitivity of the search. HF was a prerequisite for our search. The search fields used included "heart failure," "vaccination," "influenza," "immunization" along with variants of these terms. No restrictions on the type of study design were applied. The most common clinical scenario is exacerbation of pre-existing CHF by influenza infection. Scarce evidence supports a potential positive association of influenza infection with AHF. Vaccinated patients with pre-existing CHF have reduced all-cause morbidity and mortality, but effects are not consistently documented. Immunization with higher antigen quantity may confer additional protection, but such aggressive approach has not been generally advocated. Further studies are needed to delineate the role of influenza infection on AHF/CHF pathogenesis and maintenance. Annual anti-influenza vaccination appears to be an effective measure for secondary prevention in HF. Better immunization strategies and more efficacious vaccines are urgently necessary.

'Hearts and minds': association, causation and implication of cognitive impairment in heart failure.

Science.gov (United States)

Cannon, Jane A; McMurray, John Jv; Quinn, Terry J

2015-01-01

The clinical syndrome of heart failure is one of the leading causes of hospitalisation and mortality in older adults. An association between cognitive impairment and heart failure is well described but our understanding of the relationship between the two conditions remains limited. In this review we provide a synthesis of available evidence, focussing on epidemiology, the potential pathogenesis, and treatment implications of cognitive decline in heart failure. Most evidence available relates to heart failure with reduced ejection fraction and the syndromes of chronic cognitive decline or dementia. These conditions are only part of a complex heart failure-cognition paradigm. Associations between cognition and heart failure with preserved ejection fraction and between acute delirium and heart failure also seem evident and where data are available we will discuss these syndromes. Many questions remain unanswered regarding heart failure and cognition. Much of the observational evidence on the association is confounded by study design, comorbidity and insensitive cognitive assessment tools. If a causal link exists, there are several potential pathophysiological explanations. Plausible underlying mechanisms relating to cerebral hypoperfusion or occult cerebrovascular disease have been described and it seems likely that these may coexist and exert synergistic effects. Despite the prevalence of the two conditions, when cognitive impairment coexists with heart failure there is no specific guidance on treatment. Institution of evidence-based heart failure therapies that reduce mortality and hospitalisations seems intuitive and there is no signal that these interventions have an adverse effect on cognition. However, cognitive impairment will present a further barrier to the often complex medication self-management that is required in contemporary heart failure treatment.

Numerical Analysis of Blood Damage Potential of the HeartMate II and HeartWare HVAD Rotary Blood Pumps.

Science.gov (United States)

Thamsen, Bente; Blümel, Bastian; Schaller, Jens; Paschereit, Christian O; Affeld, Klaus; Goubergrits, Leonid; Kertzscher, Ulrich

2015-08-01

Implantable left ventricular assist devices (LVADs) became the therapy of choice in treating end-stage heart failure. Although survival improved substantially and is similar in currently clinically implanted LVADs HeartMate II (HM II) and HeartWare HVAD, complications related to blood trauma are frequently observed. The aim of this study was to compare these two pumps regarding their potential blood trauma employing computational fluid dynamics. High-resolution structured grids were generated for the pumps. Newtonian flow was calculated, solving Reynolds-averaged Navier-Stokes equations with a sliding mesh approach and a k-ω shear stress transport turbulence model for the operating point of 4.5 L/min and 80 mm Hg. The pumps were compared in terms of volumes subjected to certain viscous shear stress thresholds, below which no trauma was assumed (von Willebrand factor cleavage: 9 Pa, platelet activation: 50 Pa, and hemolysis: 150 Pa), and associated residence times. Additionally, a hemolysis index was calculated based on a Eulerian transport approach. Twenty-two percent of larger volumes above 9 Pa were observed in the HVAD; above 50 Pa and 150 Pa the differences between the two pumps were marginal. Residence times were higher in the HVAD for all thresholds. The hemolysis index was almost equal for the HM II and HVAD. Besides the gap regions in both pumps, the inlet regions of the rotor and diffuser blades have a high hemolysis production in the HM II, whereas in the HVAD, the volute tongue is an additional site for hemolysis production. Thus, in this study, the comparison of the HM II and the HVAD using numerical methods indicated an overall similar tendency to blood trauma in both pumps. However, influences of turbulent shear stresses were not considered and effects of the pivot bearing in the HM II were not taken into account. Further in vitro investigations are required. Copyright © 2015 International Center for Artificial Organs and Transplantation and

Do field-free electromagnetic potentials play a role in biology?

Science.gov (United States)

Szasz, A; Vincze, G; Andocs, G; Szasz, O

2009-01-01

All bio-systems are imperfect dielectrics. Their general properties however cannot be described by conventional simple electrodynamics; the system is more complex. A central question in our present paper is centered on a controversial debate of the possible effect of the zero fields (only potentials exist). We show that the identical use of the "field-free," "curl-free," and "force-free" terminologies is incorrect, there have definitely different meanings. It is shown that the effective electro-dynamical parameters that describe and modify living systems are the potentials and not the fields. We discuss how the potentials have a role in biological processes even in field-free cases.

Loss of ATP-Sensitive Potassium Channel Surface Expression in Heart Failure Underlies Dysregulation of Action Potential Duration and Myocardial Vulnerability to Injury.

Directory of Open Access Journals (Sweden)

Zhan Gao

Full Text Available The search for new approaches to treatment and prevention of heart failure is a major challenge in medicine. The adenosine triphosphate-sensitive potassium (KATP channel has been long associated with the ability to preserve myocardial function and viability under stress. High surface expression of membrane KATP channels ensures a rapid energy-sparing reduction in action potential duration (APD in response to metabolic challenges, while cellular signaling that reduces surface KATP channel expression blunts APD shortening, thus sacrificing energetic efficiency in exchange for greater cellular calcium entry and increased contractile force. In healthy hearts, calcium/calmodulin-dependent protein kinase II (CaMKII phosphorylates the Kir6.2 KATP channel subunit initiating a cascade responsible for KATP channel endocytosis. Here, activation of CaMKII in a transaortic banding (TAB model of heart failure is coupled with a 35-40% reduction in surface expression of KATP channels compared to hearts from sham-operated mice. Linkage between KATP channel expression and CaMKII is verified in isolated cardiomyocytes in which activation of CaMKII results in downregulation of KATP channel current. Accordingly, shortening of monophasic APD is slowed in response to hypoxia or heart rate acceleration in failing compared to non-failing hearts, a phenomenon previously shown to result in significant increases in oxygen consumption. Even in the absence of coronary artery disease, failing myocardium can be further injured by ischemia due to a mismatch between metabolic supply and demand. Ischemia-reperfusion injury, following ischemic preconditioning, is diminished in hearts with CaMKII inhibition compared to wild-type hearts and this advantage is largely eliminated when myocardial KATP channel expression is absent, supporting that the myocardial protective benefit of CaMKII inhibition in heart failure may be substantially mediated by KATP channels. Recognition of Ca

Off disk-center potential field calculations using vector magnetograms

Science.gov (United States)

Venkatakrishnan, P.; Gary, G. Allen

1989-01-01

A potential field calculation for off disk-center vector magnetograms that uses all the three components of the measured field is investigated. There is neither any need for interpolation of grid points between the image plane and the heliographic plane nor for an extension or a truncation to a heliographic rectangle. Hence, the method provides the maximum information content from the photospheric field as well as the most consistent potential field independent of the viewing angle. The introduction of polarimetric noise produces a less tolerant extrapolation procedure than using the line-of-sight extrapolation, but the resultant standard deviation is still small enough for the practical utility of this method.

Participation in Heart-Healthy Behaviors: A Secondary Analysis of the American Heart Association Go Red Heart Match Data.

Science.gov (United States)

Arslanian-Engoren, Cynthia; Eastwood, Jo-Ann; De Jong, Marla J; Berra, Kathy

2015-01-01

The American Heart Association created Go Red Heart Match, a free and secure online program that enables women to connect with each other to fight heart disease either personally or as a caregiver for someone with heart disease. Through these connections, participants have an opportunity to develop a personal, private, and supportive relationship with other women; share common experiences; and motivate and encourage each other to follow a heart-healthy lifestyle. The aims of this study were to describe the demographic characteristics of the Go Red Heart Match responders and to determine whether participation in the program prompted participants to engage in heart-healthy behaviors. A secondary analysis of data collected as part of a needs assessment survey from the American Heart Association Go Red Heart Match was conducted. A total of 117 (35%) of the 334 invited women completed the survey. Most responders were female, married, and college educated. A total of 105 (90%) responders were diagnosed with a type of heart disease or stroke and 77 (73%) responders had undergone treatment. As a result of participating in the program, 75% of the responders reported the following improvements in heart-healthy behaviors: eating a more heart-healthy diet (54%), exercising more frequently (53%), losing weight (47%), and quitting smoking (10%). Responders who had a diagnosis of heart attack (n = 48) were more likely (P = .003) to quit smoking than were those with other diagnoses (n = 69). Notably, 48% of responders reported encouraging someone else in their life to speak to their doctor about their risk for heart disease. Most women who participated in Heart Match reported engaging in new heart-healthy behaviors. The findings support expanding the existing program in a more diverse population as a potentially important way to reach women and encourage cardiovascular disease risk reduction for those with heart disease and stroke.

Characterization of Peripheral Activity States and Cortical Local Field Potentials of Mice in an Elevated Plus Maze Test.

Science.gov (United States)

Okonogi, Toya; Nakayama, Ryota; Sasaki, Takuya; Ikegaya, Yuji

2018-01-01

Elevated plus maze (EPM) tests have been used to assess animal anxiety levels. Little information is known regarding how physiological activity patterns of the brain-body system are altered during EPM tests. Herein, we monitored cortical local field potentials (LFPs), electrocardiograms (ECGs), electromyograms (EMGs), and respiratory signals in individual mice that were repeatedly exposed to EPM tests. On average, mouse heart rates were higher in open arms. In closed arms, the mice occasionally showed decreased heart and respiratory rates lasting for several seconds or minutes, characterized as low-peripheral activity states of peripheral signals. The low-activity states were observed only when the animals were in closed arms, and the frequencies of the states increased as the testing days proceeded. During the low-activity states, the delta and theta powers of cortical LFPs were significantly increased and decreased, respectively. These results demonstrate that cortical oscillations crucially depend on whether an animal exhibits low-activity states in peripheral organs rather than the EPM arm in which the animal is located. These results suggest that combining behavioral tests with physiological makers enables a more accurate evaluation of rodent mental states.

Characterization of Peripheral Activity States and Cortical Local Field Potentials of Mice in an Elevated Plus Maze Test

Directory of Open Access Journals (Sweden)

Toya Okonogi

2018-04-01

Full Text Available Elevated plus maze (EPM tests have been used to assess animal anxiety levels. Little information is known regarding how physiological activity patterns of the brain-body system are altered during EPM tests. Herein, we monitored cortical local field potentials (LFPs, electrocardiograms (ECGs, electromyograms (EMGs, and respiratory signals in individual mice that were repeatedly exposed to EPM tests. On average, mouse heart rates were higher in open arms. In closed arms, the mice occasionally showed decreased heart and respiratory rates lasting for several seconds or minutes, characterized as low-peripheral activity states of peripheral signals. The low-activity states were observed only when the animals were in closed arms, and the frequencies of the states increased as the testing days proceeded. During the low-activity states, the delta and theta powers of cortical LFPs were significantly increased and decreased, respectively. These results demonstrate that cortical oscillations crucially depend on whether an animal exhibits low-activity states in peripheral organs rather than the EPM arm in which the animal is located. These results suggest that combining behavioral tests with physiological makers enables a more accurate evaluation of rodent mental states.

Potential vorticity field in the Bay of Bengal during southwest monsoon

Digital Repository Service at National Institute of Oceanography (India)

Murty, V.S.N.; Rao, D.P.

theta), potential vorticity distribution is complex due to wind and freshwater forcings. The beta -effect dominates the potential vorticity field on 26.9 sigma theta isopycnal. The field of potential vorticity closely follows that of circulation...

Understanding the C-pulse device and its potential to treat heart failure.

Science.gov (United States)

Sales, Virna L; McCarthy, Patrick M

2010-03-01

The Sunshine Heart C-Pulse (C-Pulse; Sunshine Heart Inc., Tustin, CA) device is an extra-aortic implantable counterpulsation pump designed as a non-blood contacting ambulatory heart assist device, which may provide relief from symptoms for class II-III congestive heart failure patients. It has a comparable hemodynamic augmentation to intra-aortic balloon counterpulsation devices. The C-Pulse cuff is implanted through a median sternotomy, secured around the ascending aorta, and pneumatically driven by an external system controller. Pre-clinical studies in the acute pig model, and initial temporary clinical studies in patients undergoing off-pump coronary bypass surgery have shown substantial increase in diastolic perfusion of the coronary vessels, which translated to a favorable improvement in ventricular function. A U.S. prospective multi-center trial to evaluate the safety and efficacy of the C-Pulse in class III patients with moderate heart failure is now in progress.

The potential role of honey and its polyphenols in preventing heart ...

African Journals Online (AJOL)

Many epidemiological studies have shown that regular intake of phenolic compounds is associated with reduced risk of heart diseases. In coronary heart disease, the protective effects of phenolic compounds include mainly antithrombotic, anti-ischemic, anti-oxidant, and vasorelaxant. It is suggested that flavonoids decrease ...

Evidence-based medicine and patient choice: the case of heart failure care.

Science.gov (United States)

Sanders, Tom; Harrison, Stephen; Checkland, Kath

2008-04-01

The implementation of evidence-based medicine and policies aimed at increasing user involvement in health care decisions are central planks of contemporary English health policy. Yet they are potentially in conflict. Our aim was to explore how clinicians working in the field of heart failure resolve this conflict. Qualitative semi-structured interviews were carried out with health professionals who were currently caring for patients with heart failure, and observations were conducted at one dedicated heart failure clinic in northern England. While clinicians acknowledged that patients' ideas and preferences should be an important part of treatment decisions, the widespread acceptance of an evidence-based clinical protocol for heart failure among the clinic doctors significantly influenced the content and style of the consultation. Evidence-based medicine was used to buttress professional authority and seemed to provide an additional barrier to the adoption of patient-centred clinical practice.

Heart rate variability affected by radiofrequency electromagnetic field in adolescent students.

Science.gov (United States)

Misek, Jakub; Belyaev, Igor; Jakusova, Viera; Tonhajzerova, Ingrid; Barabas, Jan; Jakus, Jan

2018-05-01

This study examines the possible effect of radiofrequency (RF) electromagnetic fields (EMF) on the autonomic nervous system (ANS). The effect of RF EMF on ANS activity was studied by measuring heart rate variability (HRV) during ortho-clinostatic test (i.e., transition from lying to standing and back) in 46 healthy grammar school students. A 1788 MHz pulsed wave with intensity of 54 ± 1.6 V/m was applied intermittently for 18 min in each trial. Maximum specific absorption rate (SAR 10 ) value was determined to 0.405 W/kg. We also measured the respiration rate and estimated a subjective perception of EMF exposure. RF exposure decreased heart rate of subjects in a lying position, while no such change was seen in standing students. After exposure while lying, a rise in high frequency band of HRV and root Mean Square of the Successive Differences was observed, which indicated an increase in parasympathetic nerve activity. Tympanic temperature and skin temperature were measured showing no heating under RF exposure. No RF effect on respiration rate was observed. None of the tested subjects were able to distinguish real exposure from sham exposure when queried at the end of the trial. In conclusion, short-term RF EMF exposure of students in a lying position during the ortho-clinostatic test affected ANS with significant increase in parasympathetic nerve activity compared to sham exposed group. Bioelectromagnetics. 39:277-288, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Verification of Heart Disease: Implications for a New Heart Transplantation Allocation System.

Science.gov (United States)

Raeisi-Giglou, Pejman; Rodriguez, E Rene; Blackstone, Eugene H; Tan, Carmela D; Hsich, Eileen M

2017-12-01

This study sought to determine the accuracy of the pre-transplantation clinical diagnosis of heart disease in the United Network for Organ Sharing (UNOS) database. Because survival on the heart transplantation waitlist depends on underlying heart disease, a new allocation system will include the type of heart disease. Accuracy of the pre-transplantation clinical diagnosis and the effect of misclassification are unknown. We included all adults who received transplants at our center between January 2009 to December 2015. We compared the pre-transplantation clinical diagnosis at listing with pathology of the explanted heart and determined the potential effect of misclassification with the proposed allocation system. A total of 334 patients had the following clinical cardiac diagnoses at listing: 148 had dilated cardiomyopathy, 19 had restrictive cardiomyopathy, 103 had ischemic cardiomyopathy, 24 had hypertrophic cardiomyopathy, 11 had valvular disease, 16 had congenital heart disease (CHD), and 13 patients had a diagnosis of "other." Pathology of the explanted hearts revealed 82% concordance and 18% discordance (10% coding errors and 8% incorrect diagnosis). The most common incorrect diagnoses were sarcoidosis (66%), arrhythmogenic right ventricular dysplasia (60%), and other causes of predominately right-sided heart failure (33%). Among the misclassified diagnoses, 40% were listed as UNOS status 2, 8% remained at status 2 at transplantation, and only sarcoidosis and CHD were potentially at a disadvantage with the new allocation. There is high concordance between clinical and pathologic diagnosis, except for sarcoidosis and genetic diseases. Few misclassifications result in disadvantages to patients based on the new allocation system, but rare diseases like sarcoidosis remain problematic. To improve the UNOS database and enhance outcome research, pathology of the explanted hearts should be required post-transplantation. Copyright © 2017 American College of

Field-aligned plasma-potential structure formed by local electron cyclotron resonance

International Nuclear Information System (INIS)

Hatakeyama, Rikizo; Kaneko, Toshiro; Sato, Noriyoshi

2001-01-01

The significance of basic experiments on field-aligned plasma-potential structure formed by local electron cyclotron resonance (ECR) is claimed based on the historical development of the investigation on electric double layer and electrostatic potential confinement of open-ended fusion-oriented plasmas. In the presence of a single ECR point in simple mirror-type configurations of magnetic field, a potential dip (thermal barrier) appears around this point, being followed by a subsequent potential hump (plug potential) along a collisionless plasma flow. The observed phenomenon gives a clear-cut physics to the formation of field-aligned plug potential with thermal barrier, which is closely related to the double layer formation triggered by a negative dip. (author)

Exercise echocardiography for structural heart disease.

Science.gov (United States)

Izumo, Masaki; Akashi, Yoshihiro J

2016-03-01

Since the introduction of transcatheter structural heart intervention, the term "structural heart disease" has been widely used in the field of cardiology. Structural heart disease refers to congenital heart disease, valvular heart disease, and cardiomyopathy. In structural heart disease, valvular heart disease is frequently identified in the elderly. Of note, the number of patients who suffer from aortic stenosis (AS) and mitral regurgitation (MR) is increasing in developed countries because of the aging of the populations. Transcatheter aortic valve replacement and percutaneous mitral valve repair has been widely used for AS and MR, individually. Echocardiography is the gold standard modality for initial diagnosis and subsequent evaluation of AS and MR, although the difficulties in assessing patients with these diseases still remain. Here, we review the clinical usefulness and prognostic impact of exercise echocardiography on structural heart disease, particularly on AS and MR.

Radiology of congenital heart disease

International Nuclear Information System (INIS)

Amplatz, K.

1986-01-01

This is a text on the radiologic diagnosis of congenital heart disease and its clinical manifestations. The main thrust of the book is the logical approach which allows an understanding of the complex theory of congenital heart disease. The atlas gives a concise overview of the entire field of congenital heart disease. Emphasis is placed on the understanding of the pathophysiology and its clinical and radiological consequences. Surgical treatment is included since it provides a different viewpoint of the anatomy

AcvR1-mediated BMP signaling in second heart field is required for arterial pole development: implications for myocardial differentiation and regional identity.

Science.gov (United States)

Thomas, Penny S; Rajderkar, Sudha; Lane, Jamie; Mishina, Yuji; Kaartinen, Vesa

2014-06-15

BMP signaling plays an essential role in second heart field-derived heart and arterial trunk development, including myocardial differentiation, right ventricular growth, and interventricular, outflow tract and aortico-pulmonary septation. It is mediated by a number of different BMP ligands, and receptors, many of which are present simultaneously. The mechanisms by which they regulate morphogenetic events and degree of redundancy amongst them have still to be elucidated. We therefore assessed the role of BMP Type I receptor AcvR1 in anterior second heart field-derived cell development, and compared it with that of BmpR1a. By removing Acvr1 using the driver Mef2c[AHF]-Cre, we show that AcvR1 plays an essential role in arterial pole morphogenesis, identifying defects in outflow tract wall and cushion morphology that preceded a spectrum of septation defects from double outlet right ventricle to common arterial trunk in mutants. Its absence caused dysregulation in gene expression important for myocardial differentiation (Isl1, Fgf8) and regional identity (Tbx2, Tbx3, Tbx20, Tgfb2). Although these defects resemble to some degree those in the equivalent Bmpr1a mutant, a novel gene knock-in model in which Bmpr1a was expressed in the Acvr1 locus only partially restored septation in Acvr1 mutants. These data show that both BmpR1a and AcvR1 are needed for normal heart development, in which they play some non-redundant roles, and refine our understanding of the genetic and morphogenetic processes underlying Bmp-mediated heart development important in human congenital heart disease. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of electromagnetic radiation (bright light, extremely low-frequency magnetic fields, infrared radiation) on the circadian rhythm of melatonin synthesis, rectal temperature, and heart rate.

Science.gov (United States)

Griefahn, Barbara; Künemund, Christa; Blaszkewicz, Meinolf; Lerchl, Alexander; Degen, Gisela H

2002-10-01

Electromagnetic spectra reduce melatonin production and delay the nadirs of rectal temperature and heart rate. Seven healthy men (16-22 yrs) completed 4 permuted sessions. The control session consisted of a 24-hours bedrest at infrared radiation (65 degrees C) was applied from 5 pm to 1 am. Salivary melatonin level was determined hourly, rectal temperature and heart rate were continuously recorded. Melatonin synthesis was completely suppressed by light but resumed thereafter. The nadirs of rectal temperature and heart rate were delayed. The magnetic field had no effect. Infrared radiation elevated rectal temperature and heart rate. Only bright light affected the circadian rhythms of melatonin synthesis, rectal temperature, and heart rate, however, differently thus causing a dissociation, which might enhance the adverse effects of shiftwork in the long run.

Increased transient receptor potential vanilloid type 1 (TRPV1) channel expression in hypertrophic heart

DEFF Research Database (Denmark)

Thilo, Florian; Liu, Ying; Schulz, Nico

2010-01-01

The aim of this study was to compare the expression of transient receptor potential vanilloid type 1 (TRPV1) channels in hypertrophic hearts from transgenic mice showing overexpression of the catalytic subunit alpha of protein phosphatase 2A alpha (PP2Ac alpha) with wild-type mice and with TRPV1-...... alpha transgenic mice compared to wild-type mice and TRPV1-/- mice (8.6±1.3mg/g; 5.4±0.3mg/g; and 5.4±0.4mg/g; respectively; p...

[Effect of pulse magnetic field on distribution of neuronal action potential].

Science.gov (United States)

Zheng, Yu; Cai, Di; Wang, Jin-Hai; Li, Gang; Lin, Ling

2014-08-25

The biological effect on the organism generated by magnetic field is widely studied. The present study was aimed to observe the change of sodium channel under magnetic field in neurons. Cortical neurons of Kunming mice were isolated, subjected to 15 Hz, 1 mT pulse magnetic stimulation, and then the currents of neurons were recorded by whole-cell patch clamp. The results showed that, under magnetic stimulation, the activation process of Na(+) channel was delayed, and the inactivation process was accelerated. Given the classic three-layer model, the polarization diagram of cell membrane potential distribution under pulse magnetic field was simulated, and it was found that the membrane potential induced was associated with the frequency and intensity of magnetic field. Also the effect of magnetic field-induced current on action potential was simulated by Hodgkin-Huxley (H-H) model. The result showed that the generation of action potential was delayed, and frequency and the amplitudes were decreased when working current was between -1.32 μA and 0 μA. When the working current was higher than 0 μA, the generation frequency of action potential was increased, and the change of amplitudes was not obvious, and when the working current was lower than -1.32 μA, the time of rising edge and amplitudes of action potential were decreased drastically, and the action potential was unable to generate. These results suggest that the magnetic field simulation can affect the distribution frequency and amplitude of action potential of neuron via sodium channel mediation.

Employment after heart transplantation among adults with congenital heart disease.

Science.gov (United States)

Tumin, Dmitry; Chou, Helen; Hayes, Don; Tobias, Joseph D; Galantowicz, Mark; McConnell, Patrick I

2017-12-01

Adults with congenital heart disease may require heart transplantation for end-stage heart failure. Whereas heart transplantation potentially allows adults with congenital heart disease to resume their usual activities, employment outcomes in this population are unknown. Therefore, we investigated the prevalence and predictors of work participation after heart transplantation for congenital heart disease. Retrospective review of a prospective registry. United Network for Organ Sharing registry of transplant recipients in the United States. Adult recipients of first-time heart transplantation with a primary diagnosis of congenital heart disease, performed between 2004 and 2015. None. Employment status reported by transplant centers at required follow-up intervals up to 5 y posttransplant. Among 470 patients included in the analysis (mean follow-up: 5 ± 3 y), 127 (27%) worked after transplant, 69 (15%) died before beginning or returning to work, and 274 (58%) survived until censoring, but did not participate in paid work. Multivariable competing-risks regression analysis examined characteristics associated with posttransplant employment, accounting for mortality as a competing outcome. In descriptive and multivariable analysis, pretransplant work participation was associated with a greater likelihood of posttransplant employment, while the use of Medicaid insurance at the time of transplant was associated with a significantly lower likelihood of working after transplant (subhazard ratio compared to private insurance: 0.55; 95% confidence interval: 0.32, 0.95; P = .032). Employment was rare after heart transplantation for congenital heart disease, and was significantly less common than in the broader population of adults with congenital heart disease. Differences in return to work were primarily related to pretransplant employment and the use of public insurance, rather than clinical characteristics. © 2017 Wiley Periodicals, Inc.

Locomotor, Heart-Rate, and Metabolic Power Characteristics of Youth Women's Field Hockey: Female Athletes in Motion (FAiM) Study

Science.gov (United States)

Vescovi, Jason D.

2016-01-01

Purpose: The purpose of this study was to quantify the locomotor, heart-rate, and metabolic power characteristics of high-level youth female field hockey matches. Method: Players from the U21 and U17 Canadian women's national teams were monitored during a 4-match test series using Global Positioning System technology. Position (forward,…

A simulation of T-wave alternans vectocardiographic representation performed by changing the ventricular heart cells action potential duration.

Science.gov (United States)

Janusek, D; Kania, M; Zaczek, R; Zavala-Fernandez, H; Maniewski, R

2014-04-01

The presence of T wave alternans (TWA) in the surface ECG signals has been recognized as a marker of electrical instability, and is hypothesized to be related to patients at increased risk for ventricular arrhythmias. In this paper we present a TWA simulation study. The TWA phenomenon was simulated by changing the duration of the ventricular heart cells action potential. The magnitude was calculated in the surface ECG with the use of the time domain method. The spatially concordant TWA, where during one heart beat all ventricular cells display a short-duration action potential and during the next beat they exhibit a long-duration action potential, as well as the discordant TWA, where at least one region is out of phase, was simulated. The vectocardiographic representation was employed. The obtained results showed a high level of T-loop pattern and location disturbances connected to the discordant TWA simulation in contrast to the concordant one. This result may be explained by the spatial heterogeneity of the ventricular repolarization process, which could be higher for the discordant TWA than for the concordant TWA. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Small-volume amnioinfusion: a potential stimulus of intrapartum fetal heart rate accelerations.

Science.gov (United States)

Wax, Joseph R; Flaherty, Nina; Pinette, Michael G; Blackstone, Jacquelyn; Cartin, Angelina

2004-02-01

We describe a recurrent nonreassuring fetal heart rate pattern in which small-volume amnioinfusions apparently evoked fetal heart rate accelerations suggested fetal well-being, allowing that progressive labor that culminated in the vaginal delivery of a healthy infant.

Generating functionals for quantum field theories with random potentials

International Nuclear Information System (INIS)

Jain, Mudit; Vanchurin, Vitaly

2016-01-01

We consider generating functionals for computing correlators in quantum field theories with random potentials. Examples of such theories include cosmological systems in context of the string theory landscape (e.g. cosmic inflation) or condensed matter systems with quenched disorder (e.g. spin glass). We use the so-called replica trick to define two different generating functionals for calculating correlators of the quantum fields averaged over a given distribution of random potentials. The first generating functional is appropriate for calculating averaged (in-out) amplitudes and involves a single replica of fields, but the replica limit is taken to an (unphysical) negative one number of fields outside of the path integral. When the number of replicas is doubled the generating functional can also be used for calculating averaged probabilities (squared amplitudes) using the in-in construction. The second generating functional involves an infinite number of replicas, but can be used for calculating both in-out and in-in correlators and the replica limits are taken to only a zero number of fields. We discuss the formalism in details for a single real scalar field, but the generalization to more fields or to different types of fields is straightforward. We work out three examples: one where the mass of scalar field is treated as a random variable and two where the functional form of interactions is random, one described by a Gaussian random field and the other by a Euclidean action in the field configuration space.

Decoupling Action Potential Bias from Cortical Local Field Potentials

Directory of Open Access Journals (Sweden)

Stephen V. David

2010-01-01

Full Text Available Neurophysiologists have recently become interested in studying neuronal population activity through local field potential (LFP recordings during experiments that also record the activity of single neurons. This experimental approach differs from early LFP studies because it uses high impendence electrodes that can also isolate single neuron activity. A possible complication for such studies is that the synaptic potentials and action potentials of the small subset of isolated neurons may contribute disproportionately to the LFP signal, biasing activity in the larger nearby neuronal population to appear synchronous and cotuned with these neurons. To address this problem, we used linear filtering techniques to remove features correlated with spike events from LFP recordings. This filtering procedure can be applied for well-isolated single units or multiunit activity. We illustrate the effects of this correction in simulation and on spike data recorded from primary auditory cortex. We find that local spiking activity can explain a significant portion of LFP power at most recording sites and demonstrate that removing the spike-correlated component can affect measurements of auditory tuning of the LFP.

Solution to reinforcement learning problems with artificial potential field

Institute of Scientific and Technical Information of China (English)

XIE Li-juan; XIE Guang-rong; CHEN Huan-wen; LI Xiao-li

2008-01-01

A novel method was designed to solve reinforcement learning problems with artificial potential field. Firstly a reinforcement learning problem was transferred to a path planning problem by using artificial potential field(APF), which was a very appropriate method to model a reinforcement learning problem. Secondly, a new APF algorithm was proposed to overcome the local minimum problem in the potential field methods with a virtual water-flow concept. The performance of this new method was tested by a gridworld problem named as key and door maze. The experimental results show that within 45 trials, good and deterministic policies are found in almost all simulations. In comparison with WIERING's HQ-learning system which needs 20 000 trials for stable solution, the proposed new method can obtain optimal and stable policy far more quickly than HQ-learning. Therefore, the new method is simple and effective to give an optimal solution to the reinforcement learning problem.

Feasibility and Diagnostic Accuracy of Whole Heart Coronary MR Angiography Using Free-Breathing 3D Balanced Turbo-Field-Echo with SENSE and the Half-Fourier Acquisition Technique

International Nuclear Information System (INIS)

Kim, Young Jin; Seo, Jae Seung; Choi, Byoung Wook; Choe, Kyu Ok; Jang, Yang Soo; Ko, Young Guk

2006-01-01

We wanted to assess the feasibility and diagnostic accuracy of whole heart coronary magnetic resonance angiography (MRA) with using 3D balanced turbo-field-echo (b-TFE) with SENSE and the half-Fourier acquisition technique for identifying stenoses of the coronary artery. Twenty-one patients who underwent both whole heart coronary MRA examinations and conventional catheter coronary angiography examinations were enrolled in the study. The whole heart coronary MRA images were acquired using a navigator gated 3D b-TFE sequence with SENSE and the half-Fourier acquisition technique to reduce the acquisition time. The imaging slab covered the whole heart (80 contiguous slices with a reconstructed slice thickness of 1.5 mm) along the transverse axis. The quality of the images was evaluated by using a 5-point scale (0 - uninterpretable, 1 - poor, 2 - fair, 3 - good, 4 - excellent). Ten coronary segments of the heart were evaluated in each case; the left main coronary artery (LM), and the proximal, middle and distal segments of the left anterior descending (LAD), the left circumflex (LCX) and the right coronary artery (RCA). The diagnostic accuracy of whole heart coronary MRA for detecting significant coronary artery stenosis was determined on the segment-bysegment basis, and it was compared with the results obtained by conventional catheter angiography, which is the gold standard. The mean image quality was 3.7 in the LM, 3.2 in the LAD, 2.5 in the LCX, and 3.3 in the RCA, respectively (the overall image quality was 3.0 ± 0.1). 168 (84%) of the 201 segments had an acceptable image quality (≥ grade 2). The sensitivity, specificity, accuracy, negative predictive value and positive predictive value of the whole heart coronary MRA images for detecting significant stenosis were 81.3%, 92.1%, 91.1%, 97.9%, and 52.0%, respectively. The mean coronary MRA acquisition time was 9 min 22 sec (± 125 sec). Whole heart coronary MRA is a feasible technique, and it has good potential to

A pilot investigation of the effect of extremely low frequency pulsed electromagnetic fields on humans' heart rate variability.

Science.gov (United States)

Baldi, Emilio; Baldi, Claudio; Lithgow, Brian J

2007-01-01

The question whether pulsed electromagnetic field (PEMF) can affect the heart rhythm is still controversial. This study investigates the effects on the cardiocirculatory system of ELF-PEMFs. It is a follow-up to an investigation made of the possible therapeutic effect ELF-PEMFs, using a commercially available magneto therapeutic unit, had on soft tissue injury repair in humans. Modulation of heart rate (HR) or heart rate variability (HRV) can be detected from changes in periodicity of the R-R interval and/or from changes in the numbers of heart-beat/min (bpm), however, R-R interval analysis gives only a quantitative insight into HRV. A qualitative understanding of HRV can be obtained considering the power spectral density (PSD) of the R-R intervals Fourier transform. In this study PSD is the investigative tool used, more specifically the low frequency (LF) PSD and high frequency (HF) PSD ratio (LF/HF) which is an indicator of sympatho-vagal balance. To obtain the PSD value, variations of the R-R time intervals were evaluated from a continuously recorded ECG. The results show a HR variation in all the subjects when they are exposed to the same ELF-PEMF. This variation can be detected by observing the change in the sympatho-vagal equilibrium, which is an indicator of modulation of heart activity. Variation of the LF/HF PSD ratio mainly occurs at transition times from exposure to nonexposure, or vice versa. Also of interest are the results obtained during the exposure of one subject to a range of different ELF-PEMFs. This pilot study suggests that a full investigation into the effect of ELF-PEMFs on the cardiovascular system is justified.

A Biobank for Long-term and Sustainable Research in the Field of Congenital Heart Disease in Germany

Directory of Open Access Journals (Sweden)

Thomas Pickardt

2016-08-01

Full Text Available Congenital heart disease (CHD is the most frequent birth defect (0.8%–1% of all live births. Due to the advance in prenatal and postnatal early diagnosis and treatment, more than 90% of these patients survive into adulthood today. However, several mid- and long-term morbidities are dominating the follow-up of these patients. Due to the rarity and heterogeneity of the phenotypes of CHD, multicenter registry-based studies are required. The CHD-Biobank was established in 2009 with the aim to collect DNA from patients and their parents (trios or from affected families, as well as cardiovascular tissues from patients undergoing corrective heart surgery for cardiovascular malformations. Clinical/phenotype data are matched to the International Paediatric and Congenital Cardiac Code (IPCCC and the International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10. The DNA collection currently comprises samples from approximately 4200 participants with a wide range of CHD phenotypes. The collection covers about 430 trios and 120 families with more than one affected member. The cardiac tissue collection comprises 1143 tissue samples from 556 patients after open heart surgery. The CHD-Biobank provides a comprehensive basis for research in the field of CHD with high standards of data privacy, IT management, and sample logistics.

The Total Artificial Heart in End-Stage Congenital Heart Disease.

Science.gov (United States)

Villa, Chet R; Morales, David L S

2017-01-01

The development of durable ventricular assist devices (VADs) has improved mortality rates and quality of life in patients with end stage heart failure. While the use of VADs has increased dramatically in recent years, there is limited experience with VAD implantation in patients with complex congenital heart disease (CHD), despite the fact that the number of patients with end stage CHD has grown due to improvements in surgical and medical care. VAD use has been limited in patients with CHD and end stage heart failure due to anatomic (systemic right ventricle, single ventricle, surgically altered anatomy, valve dysfunction, etc.) and physiologic constraints (diastolic dysfunction). The total artificial heart (TAH), which has right and left sided pumps that can be arranged in a variety of orientations, can accommodate the anatomic variation present in CHD patients. This review provides an overview of the potential use of the TAH in patients with CHD.

Step-wise potential development across the lipid bilayer under external electric fields

Science.gov (United States)

Majhi, Amit Kumar

2018-04-01

Pore formation across the bilayers under external electric field is an important phenomenon, which has numerous applications in biology and bio-engineering fields. However, it is not a ubiquitous event under all field applications. To initiate a pore in the bilayer a particular threshold electric field is required. The electric field alters the intrinsic potential distribution across the bilayer as we as it enhances total potential drop across the bilayer, which causes the pore formation. The intrinsic potential profile has a maximum peak value, which is 0.8 V and it gets enhanced under application of external field, 0.43 V/nm. The peak value becomes 1.4 V when a pore appears in the bilayer and it continues to evolve as along as the external electric field remains switched on.

Physical correlates of radiologic heart volume

International Nuclear Information System (INIS)

Christie, D.

1978-01-01

Radiologic heart volume was calculated on a 10 per cent random sample of subjects examined in the London Civil Service Health Survey. Data were available for 1 188 men over the age of 40, and the importance of correcting radiologic heart volume for body size, age and heart rate was demonstrated. After these variables were taken into account, the most important association found was with blood pressure. Radiologic heart volume has potential value in cardiovascular screening programmes. (Auth.)

Restoration of heart functions using human embryonic stem cells derived heart muscle cells.

Science.gov (United States)

Gepstein, Lior; Kehat, Izhak

2005-02-01

Extract: Recent advances in molecular and cellular biology and specifically in the areas of stem cell biology and tissue engineering have paved the way for the development of a new field in biomedicine, regenerative medicine. This exciting approach seeks to develop new biological solutions, using the mobilization of endogenous stem cells or delivery of exogenous cells to replace or modify the function of diseased, absent, or malfunctioning tissue. The adult heart represents an attractive candidate for these emerging technologies, since adult cardiomyocytes have limited regenerative capacity. Thus, any significant heart cell loss or dysfunction, such as occurs during heart attack, is mostly irreversible and may lead to the development of progressive heart failure, one of the leading causes of world-wide morbidity and mortality. Similarly, dysfunction of the specialized electrical conduction system within the heart may result in inefficient rhythm initiation or impulse conduction, leading to significant slowing of the heart rate, usually requiring the implantation of a permanent electronic pacemaker. Replacement of the dysfunctional myocardium (heart muscle) by implantation of external heart muscle cells is emerging as a novel paradigm for restoration of the myocardial electromechanical properties, but has been significantly hampered by the paucity of cell sources for human heart cells and by the relatively limited evidence for functional integration between grafted and host cells. The recently described human embryonic stem cell (hESC) lines may provide a possible solution for the aforementioned cell sourcing problem.

The potential value of integrated natriuretic peptide and echo-guided heart failure management.

Science.gov (United States)

Scali, Maria Chiara; Simioniuc, Anca; Dini, Frank Lloyd; Marzilli, Mario

2014-07-18

There is increasing interest in guiding Heart Failure (HF) therapy with Brain Natriuretic Peptide (BNP) or N-terminal prohormone of Brain Natriuretic Peptide (NT-proBNP), with the goal of lowering concentrations of these markers (and maintaining their suppression) as part of the therapeutic approach in HF. However, recent European Society of Cardiology (ESC) and American Heart Association/ American College of Cardiology (AHA/ACC) guidelines did not recommend biomarker-guided therapy in the management of HF patients. This has likely to do with the conceptual, methodological, and practical limitations of the Natriuretic Peptides (NP)-based approach, including biological variability, slow time-course, poor specificity, cost and venipuncture, as well as to the lack of conclusive scientific evidence after 15 years of intensive scientific work and industry investment in the field. An increase in NP can be associated with accumulation of extra-vascular lung water, which is a sign of impending acute heart failure. If this is the case, an higher dose of loop diuretics will improve symptoms. However, if no lung congestion is present, diuretics will show no benefit and even harm. It is only a combined clinical, bio-humoral (for instance with evaluation of renal function) and echocardiographic assessment which may unmask the pathophysiological (and possibly therapeutic) heterogeneity underlying the same clinical and NP picture. Increase in B-lines will trigger increase of loop diuretics (or dialysis); the marked increase in mitral insufficiency (at baseline or during exercise) will lead to increase in vasodilators and to consider mitral valve repair; the presence of substantial inotropic reserve during stress will give a substantially higher chance of benefit to beta-blocker or Cardiac Resynchronization Therapy (CRT). To each patient its own therapy, not with a "blind date" with symptoms and NP and carpet bombing with drugs, but with an open-eye targeted approach on the

Scalar field cosmologies with inverted potentials

Energy Technology Data Exchange (ETDEWEB)

Boisseau, B.; Giacomini, H. [Université de Tours, Laboratoire de Mathématiques et Physique Théorique, CNRS/UMR 7350, 37200 Tours (France); Polarski, D., E-mail: bruno.boisseau@lmpt.univ-tours.fr, E-mail: hector.giacomini@lmpt.univ-tours.fr, E-mail: david.polarski@umontpellier.fr [Université Montpellier and CNRS, Laboratoire Charles Coulomb, UMR 5221, F-34095 Montpellier (France)

2015-10-01

Regular bouncing solutions in the framework of a scalar-tensor gravity model were found in a recent work. We reconsider the problem in the Einstein frame (EF) in the present work. Singularities arising at the limit of physical viability of the model in the Jordan frame (JF) are either of the Big Bang or of the Big Crunch type in the EF. As a result we obtain integrable scalar field cosmological models in general relativity (GR) with inverted double-well potentials unbounded from below which possess solutions regular in the future, tending to a de Sitter space, and starting with a Big Bang. The existence of the two fixed points for the field dynamics at late times found earlier in the JF becomes transparent in the EF.

Scalar field cosmologies with inverted potentials

International Nuclear Information System (INIS)

Boisseau, B.; Giacomini, H.; Polarski, D.

2015-01-01

Regular bouncing solutions in the framework of a scalar-tensor gravity model were found in a recent work. We reconsider the problem in the Einstein frame (EF) in the present work. Singularities arising at the limit of physical viability of the model in the Jordan frame (JF) are either of the Big Bang or of the Big Crunch type in the EF. As a result we obtain integrable scalar field cosmological models in general relativity (GR) with inverted double-well potentials unbounded from below which possess solutions regular in the future, tending to a de Sitter space, and starting with a Big Bang. The existence of the two fixed points for the field dynamics at late times found earlier in the JF becomes transparent in the EF

Opinion - Thyroid (dysfunction in heart failure: is it a potential target for medical treatment?

Directory of Open Access Journals (Sweden)

Alessandro Pingitore

2005-07-01

Full Text Available Alessandro Pingitore, Giorgio IervasiInstitute of Clinical Physiology, CNR, Pisa, ItalyIntroductionCurrently, there is little doubt that activation of the neuroendocrine (NE system is predominately responsible for the progressive decline of heart function in heart failure (HF. This is due to the complex action of neurotransmitters, hormonal factors, and/or immunological pathways. Evidence that supports this point of view is the clear prognostic benefit and the reduction of HF progression by using NE-guided therapeutic approaches (SOLVD investigators 1992; Eichhorn and Bristow 1996; Packer et al 1996; Opie 2004; Solomon et al 2004. However, the fact that HF represents one of the major causes of morbidity and mortality in Western countries also suggests that the current portfolio of NE antagonists fails to completely explain and possibly counteract disease progression (Guyatt and Deveraux 2004. In this context, interest in the relationship between thyroid hormones (THs and HF is increasingly gaining prominence. The chief reason for the latter is the emerging novel actions of THs on the cardiovascular system and, more specifically, the role of TH as a prognostic biomarker of cardiac disease as well as the potential benefit of TH administration in patients with HF.

Role of suppression of the inward rectifier current in terminal action potential repolarization in the failing heart.

Science.gov (United States)

Klein, Michael G; Shou, Matie; Stohlman, Jayna; Solhjoo, Soroosh; Haigney, Myles; Tidwell, Richard R; Goldstein, Robert E; Flagg, Thomas P; Haigney, Mark C

2017-08-01

The failing heart exhibits an increased arrhythmia susceptibility that is often attributed to action potential (AP) prolongation due to significant ion channel remodeling. The inwardly rectifying K + current (I K1 ) has been reported to be reduced, but its contribution to shaping the AP waveform and cell excitability in the failing heart remains unclear. The purpose of this study was to define the effect of I K1 suppression on the cardiac AP and excitability in the normal and failing hearts. We used electrophysiological and pharmacological approaches to investigate I K1 function in a swine tachy-pacing model of heart failure (HF). Terminal repolarization of the AP (TRAP; the time constant of the exponential fit to terminal repolarization) was markedly prolonged in both myocytes and arterially perfused wedges from animals with HF. TRAP was increased by 54.1% in HF myocytes (P < .001) and 26.2% in HF wedges (P = .014). The increase in TRAP was recapitulated by the potent and specific I K1 inhibitor, PA-6 (pentamidine analog 6), indicating that I K1 is the primary determinant of the final phase of repolarization. Moreover, we find that I K1 suppression reduced the ratio of effective refractory period to AP duration at 90% of repolarization, permitting re-excitation before full repolarization, reduction of AP upstroke velocity, and likely promotion of slow conduction. Using an objective measure of terminal repolarization, we conclude that I K1 is the major determinant of the terminal repolarization time course. Moreover, suppression of I K1 prolongs repolarization and reduces postrepolarization refractoriness without marked effects on the overall AP duration. Collectively, these findings demonstrate how I K1 suppression may contribute to arrhythmogenesis in the failing heart. Published by Elsevier Inc.

Impact of the strong electromagnetic field on the QCD effective potential for homogeneous Abelian gluon field configurations

International Nuclear Information System (INIS)

Galilo, Bogdan V.; Nedelko, Sergei N.

2011-01-01

The one-loop quark contribution to the QCD effective potential for the homogeneous Abelian gluon field in the presence of an external strong electromagnetic field is evaluated. The structure of extrema of the potential as a function of the angles between chromoelectric, chromomagnetic, and electromagnetic fields is analyzed. In this setup, the electromagnetic field is considered as an external one while the gluon field represents domain structured nonperturbative gluon configurations related to the QCD vacuum in the confinement phase. Two particularly interesting gluon configurations, (anti-)self-dual and crossed orthogonal chromomagnetic and chromoelectric fields, are discussed specifically. Within this simplified framework it is shown that the strong electromagnetic fields can play a catalyzing role for a deconfinement transition. At the qualitative level, the present consideration can be seen as a highly simplified study of an impact of the electromagnetic fields generated in relativistic heavy ion collisions on the strongly interacting hadronic matter.

Computed Tomography of Prosthetic Heart Valves

NARCIS (Netherlands)

Habets, J.

2012-01-01

Prosthetic heart valve (PHV) dysfunction is an infrequent but potentially life-threatening disease with a heterogeneous clinical presentation. Patients with PHV dysfunction clinically can present with symptoms of congestive heart failure (dyspnea, fatigue, edema), fever, angina pectoris, dizziness

Heavy quark potential in a static and strong homogeneous magnetic field

Energy Technology Data Exchange (ETDEWEB)

Hasan, Mujeeb; Chatterjee, Bhaswar; Patra, Binoy Krishna [Indian Institute of Technology Roorkee, Department of Physics, Roorkee (India)

2017-11-15

We have investigated the properties of quarkonia in a thermal QCD medium in the background of strong magnetic field. For that purpose, we employ the Schwinger proper-time quark propagator in the lowest Landau level to calculate the one-loop gluon self-energy, which in the sequel gives the effective gluon propagator. As an artifact of strong magnetic field approximation (eB >> T{sup 2} and eB >> m{sup 2}), the Debye mass for massless flavors is found to depend only on the magnetic field which is the dominant scale in comparison to the scales prevalent in the thermal medium. However, for physical quark masses, it depends on both magnetic field and temperature in a low temperature and high magnetic field but the temperature dependence is very meager and becomes independent of the temperature beyond a certain temperature and magnetic field. With the above mentioned ingredients, the potential between heavy quark (Q) and anti-quark (anti Q) is obtained in a hot QCD medium in the presence of a strong magnetic field by correcting both short- and long-range components of the potential in the real-time formalism. It is found that the long-range part of the quarkonium potential is affected much more by magnetic field as compared to the short-range part. This observation facilitates us to estimate the magnetic field beyond which the potential will be too weak to bind Q anti Q together. For example, the J/ψ is dissociated at eB ∝ 10 m{sub π}{sup 2} and Υ is dissociated at eB ∝ 100 m{sub π}{sup 2} whereas its excited states, ψ{sup '} and Υ{sup '} are dissociated at smaller magnetic field eB = m{sub π}{sup 2}, 13 m{sub π}{sup 2}, respectively. (orig.)

Leaky valves : New operation improves the heart's pumping action

NARCIS (Netherlands)

Pistecky, P.; Havlik, P.; Van Kasteren, J.

2003-01-01

The action of any pump will start to decline when the valves no longer close properly. The same goes for the heart, the pump that maintains the circulation in our vascular system. Consequently, a major field of focus of open heart surgery is the repair or replacement of heart valves. Petr Havl a

Computation of 3-D magnetostatic fields using a reduced scalar potential

International Nuclear Information System (INIS)

Biro, O.; Preis, K.; Vrisk, G.; Richter, K.R.

1993-01-01

The paper presents some improvements to the finite element computation of static magnetic fields in three dimensions using a reduced magnetic scalar potential. New methods are described for obtaining an edge element representation of the rotational part of the magnetic field from a given source current distribution. In the case when the current distribution is not known in advance, a boundary value problem is set up in terms of a current vector potential. An edge element representation of the solution can be directly used in the subsequent magnetostatic calculation. The magnetic field in a D.C. arc furnace is calculated by first determining the current distribution in terms of a current vector potential. A three dimensional problem involving a permanent magnet as well as a coil is solved and the magnetic field in some points is compared with measurement results

Far-field potentials in cylindrical and rectangular volume conductors.

Science.gov (United States)

Dumitru, D; King, J C; Rogers, W E

1993-07-01

The occurrence of a transient dipole is one method of producing a far-field potential. This investigation qualitatively defines the characteristics of the near-field and far-field electrical potentials produced by a transient dipole in both cylindrical and rectangular volume conductors. Most body segments of electrophysiologic interest such as arms, legs, thorax, and neck are roughly cylindrical in shape. A centrally located dipole generator produces a nonzero equipotential region which is found to occur along the cylindrical wall at a distance from the dipole of approximately 1.4 times the cylinder's radius and 1.9 times the cylinder's radius for the center of the cylinder. This distance to the equi-potential zone along the surface wall expands but remains less than 3.0 times the cylindrical radius when the dipole is eccentrically placed. The magnitude of the equipotential region resulting from an asymmetrically placed dipole remains identical to that when the dipole is centrally located. This behavior is found to be very similar in rectangular shallow conducting volumes that model a longitudinal slice of the cylinder, thus allowing a simple experimental model of the cylinder to be utilized. Amplitudes of the equipotential region are inversely proportional to the cylindrical or rectangular volume's cross-sectional area at the location of dipolar imbalance. This study predicts that referential electrode montages, when placed at 3.0 times the radius or greater from a dipolar axially aligned far-field generator in cylindrical homogeneous volume conductors, will record only equipotential far-field effects.

[Obesity and heart].

Science.gov (United States)

Svačina, Štěpán

2014-12-01

Cardiovascular complications of obesity are traditionally considered an important complication of obesity. Obesity itself is probably not direct cause of atherosclerosis or coronary heart disease. This may occur indirectly in metabolic complications of obesity, especially diabetes and metabolic syndrome. However, thrombogenicity potential of obesity contributes to embolism and atherosclerosis development. In cardiology is well-known a phenomenon of obesity paradox when obese patients have better prognosis than thin. This is the case of heart failure and some other cardiovascular diseases. Recently, a new concept has emerged of myokines - hormones from muscle tissue that have extensive protective effects on organism and probably on heart. Whether heart is a source of myokines is uncertain. However, undoubted importance has epicardial and pericardial fatty tissue. The epicardial fatty tissue has mainly protective effects on myocardium. This fatty tissue may produce factors of inflammation affecting the myocardium. Relationship between amount of epicardial fatty tissue and coronary heart disease is rather pathogenic. Currently, it is certain that obesity brings more metabolic and cancer complications than cardiovascular and accurate contribution to pathogenic or protective character of fatty tissue in cardiology requires further research. Nevertheless, the conclusion is that adipose tissue of organism and around the heart may be in some circumstances beneficial.

Effective potential for bilocal composite fields and its ambiguity

International Nuclear Information System (INIS)

Muta, T.

1988-01-01

It is discussed that an ambiguity exists in the definition of the effective potential for bilocal composite fields which is an indispensable tool to discuss dynamical symmetry breaking. The ambiguity gives warning to arguments on the stability of ground states based on the curvature of the effective potential

Heart rate variation and electroencephalograph--the potential physiological factors for thermal comfort study.

Science.gov (United States)

Yao, Y; Lian, Z; Liu, W; Jiang, C; Liu, Y; Lu, H

2009-04-01

Human thermal comfort researches mainly focus on the relation between the environmental factors (e.g. ambient temperature, air humidity, and air velocity, etc.) and the thermal comfort sensation based on a large amount of subjective field investigations. Although some physiological factors, such as skin temperature and metabolism were used in many thermal comfort models,they are not enough to establish a perfect thermal comfort model. In this paper,another two physiological factors, i.e. heart rate variation (HRV) and electroencephalograph (EEG), are explored for the thermal comfort study. Experiments were performed to investigate how these physiological factors respond to the environmental temperatures, and what is the relationship between HRV and EEG and thermal comfort. The experimental results indicate that HRV and EEG may be related to thermal comfort, and they may be useful to understand the mechanism of thermal comfort.

Possible health hazards for cardiac pacemaker wearers from exposure to electromagnetic fields

Energy Technology Data Exchange (ETDEWEB)

1988-03-01

Cardiac pacemakers are used to provide electrical stimulation to the heart when the heart's natural rhythm is interrupted. This study shows that they can be susceptible to electromagnetic fields. Pacemakers are well protected against common electromagnetic fields, such as those from household appliances. But intense electomagnetic fields, such as those found in some industrial settings, could affect the functioning of the pacemaker. Such interference may cause the pacemaker wearer to feel dizzy or experience an accelerated heartbeat. While this is not fatal, the pacemaker wearer should try to move away from the source of the interfering field and avoid situations in which interference could arise. After experiencing any of these symptoms, the pacemaker wearer should contact a physician. Potential sources of electromagnetic interference should be identified and characterized to determine if there could be an interference hazard. Exposure to interfering electomagnetic fields should be minimized. 7 refs., 1 fig.

Report of final results regarding brain and heart tumors in Sprague-Dawley rats exposed from prenatal life until natural death to mobile phone radiofrequency field representative of a 1.8 GHz GSM base station environmental emission.

Science.gov (United States)

Falcioni, L; Bua, L; Tibaldi, E; Lauriola, M; De Angelis, L; Gnudi, F; Mandrioli, D; Manservigi, M; Manservisi, F; Manzoli, I; Menghetti, I; Montella, R; Panzacchi, S; Sgargi, D; Strollo, V; Vornoli, A; Belpoggi, F

2018-08-01

In 2011, IARC classified radiofrequency radiation (RFR) as possible human carcinogen (Group 2B). According to IARC, animals studies, as well as epidemiological ones, showed limited evidence of carcinogenicity. In 2016, the NTP published the first results of its long-term bioassays on near field RFR, reporting increased incidence of malignant glial tumors of the brain and heart Schwannoma in rats exposed to GSM - and CDMA - modulated cell phone RFR. The tumors observed in the NTP study are of the type similar to the ones observed in some epidemiological studies of cell phone users. The Ramazzini Institute (RI) performed a life-span carcinogenic study on Sprague-Dawley rats to evaluate the carcinogenic effects of RFR in the situation of far field, reproducing the environmental exposure to RFR generated by 1.8 GHz GSM antenna of the radio base stations of mobile phone. This is the largest long-term study ever performed in rats on the health effects of RFR, including 2448 animals. In this article, we reported the final results regarding brain and heart tumors. Male and female Sprague-Dawley rats were exposed from prenatal life until natural death to a 1.8 GHz GSM far field of 0, 5, 25, 50 V/m with a whole-body exposure for 19 h/day. A statistically significant increase in the incidence of heart Schwannomas was observed in treated male rats at the highest dose (50 V/m). Furthermore, an increase in the incidence of heart Schwann cells hyperplasia was observed in treated male and female rats at the highest dose (50 V/m), although this was not statistically significant. An increase in the incidence of malignant glial tumors was observed in treated female rats at the highest dose (50 V/m), although not statistically significant. The RI findings on far field exposure to RFR are consistent with and reinforce the results of the NTP study on near field exposure, as both reported an increase in the incidence of tumors of the brain and heart in RFR-exposed Sprague

Heart Failure with Recovered EF and Heart Failure with Mid-Range EF: Current Recommendations and Controversies.

Science.gov (United States)

Unkovic, Peter; Basuray, Anupam

2018-04-03

This review explores key features and potential management controversies in two emerging populations in heart failure: heart failure with recovered ejection fraction (HF-recovered EF) and heart failure with mid-range ejection fraction (HFmrEF). While HF-recovered EF patients have better outcomes than heart failure with reduced ejection fraction (HFrEF), they continue to have symptoms, persistent biomarker elevations, and abnormal outcomes suggesting a continued disease process. HFmrEF patients appear to have features of HFrEF and heart failure with preserved ejection fraction (HFpEF), but have a high prevalence of ischemic heart disease and may represent a transitory phase between the HFrEF and HFpEF. Management strategies have insufficient data to warrant standardization at this time. HF-recovered EF and HFmrEF represent new populations with unmet needs and expose the pitfalls of an EF basis for heart failure classification.

Particle localization in a double-well potential by pseudo-supersymmetric fields

International Nuclear Information System (INIS)

Bagrov, V. G.; Samsonov, B. F.; Shamshutdinova, V. V.

2011-01-01

We study properties of a particle moving in a double-well potential in the two-level approximation placed in an additional external time-dependent field. Using previously established property (J. Phys. A 41, 244023 (2008)) that any two-level system possesses a pseudo-supersymmetry we introduce the notion of pseudo-supersymmetric field. It is shown that these fields, even if their time dependence is not periodical, may produce the effect of localization of the particle in one of the wells of the double-well potential.

Dynamic positional fate map of the primary heart-forming region.

Science.gov (United States)

Cui, Cheng; Cheuvront, Tracey J; Lansford, Rusty D; Moreno-Rodriguez, Ricardo A; Schultheiss, Thomas M; Rongish, Brenda J

2009-08-15

Here we show the temporal-spatial orchestration of early heart morphogenesis at cellular level resolution, in vivo, and reconcile conflicting positional fate mapping data regarding the primary heart-forming field(s). We determined the positional fates of precardiac cells using a precision electroporation approach in combination with wide-field time-lapse microscopy in the quail embryo, a warm-blooded vertebrate (HH Stages 4 through 10). Contrary to previous studies, the results demonstrate the existence of a "continuous" circle-shaped heart field that spans the midline, appearing at HH Stage 4, which then expands to form a wide arc of progenitors at HH Stages 5-7. Our time-resolved image data show that a subset of these cardiac progenitor cells do not overlap with the expression of common cardiogenic factors, Nkx-2.5 and Bmp-2, until HH Stage 10, when a tubular heart has formed, calling into question when cardiac fate is specified and by which key factors. Sub-groups and anatomical bands (cohorts) of heart precursor cells dramatically change their relative positions in a process largely driven by endodermal folding and other large-scale tissue deformations. Thus, our novel dynamic positional fate maps resolve the origin of cardiac progenitor cells in amniotes. The data also establish the concept that tissue motion contributes significantly to cellular position fate - i.e., much of the cellular displacement that occurs during assembly of a midline heart tube (HH Stage 9) is NOT due to "migration" (autonomous motility), a commonly held belief. Computational analysis of our time-resolved data lays the foundation for more precise analyses of how cardiac gene regulatory networks correlate with early heart tissue morphogenesis in birds and mammals.

The Analytical Potential Energy Function of NH Radical Molecule in External Electric Field

International Nuclear Information System (INIS)

Wu Dong-Lan; Tan Bin; Wan Hui-Jun; Xie An-Dong; Ding Da-Jun

2015-01-01

The geometric structures of an NH radical in different external electric fields are optimized by using the density functional B3P86/cc-PV5Z method, and the bond lengths, dipole moments, vibration frequencies and IR spectrum are obtained. The potential energy curves are gained by the CCSD (T) method with the same basis set. These results indicate that the physical property parameters and potential energy curves may change with the external electric field, especially in the reverse direction electric field. The potential energy function of zero field is fitted by the Morse potential, and the fitting parameters are in good accordance with the experimental data. The potential energy functions of different external electric fields are fitted adopting the constructed potential model. The fitted critical dissociation electric parameters are shown to be consistent with the numerical calculation, and the relative errors are only 0.27% and 6.61%, hence the constructed model is reliable and accurate. The present results provide an important reference for further study of the molecular spectrum, dynamics and molecular cooling with Stark effect. (paper)

Fuzzy Pheromone Potential Fields for Virtual Pedestrian Simulation

Directory of Open Access Journals (Sweden)

Meriem Mandar

2016-01-01

Full Text Available The study of collective movement of pedestrians is crucial in various situations, such as evacuation of buildings, stadiums, or external events like concerts or public events. In such situations and under panic conditions, several incidents and disasters may arise, resulting in loss of human lives. Hence, the study and modeling of the pedestrians behavior are imperative in both normal and panic situations. In a previous work, we developed a microscopic model for pedestrian movement based on the algorithm of Ant Colonies and the principles of cellular automata. We took advantage of a fuzzy model to better reflect the uncertainty and vagueness of the perception of space to pedestrians, especially to represent the desirability or blurred visibility of virtual pedestrians. This paper uses the mechanism of artificial potential fields. Said fields provide virtual pedestrians with better visibility of their surroundings and its various components (goals and obstacles. The predictions provided by the first-order traffic flow theory are confirmed by the results of the simulation. The advantage of this model lies in the combination of benefits provided by the model of ants and artificial potential fields in a fuzzy modeling, to better understand the perceptions of pedestrians.

MicroRNAs in Heart Failure, Cardiac Transplantation, and Myocardial Recovery: Biomarkers with Therapeutic Potential.

Science.gov (United States)

Shah, Palak; Bristow, Michael R; Port, J David

2017-12-01

Heart failure is increasing in prevalence with a lack of recently developed therapies that produce major beneficial effects on its associated mortality. MicroRNAs are small non-coding RNA molecules that regulate gene expression, are differentially regulated in heart failure, and are found in the circulation serving as a biomarker of heart failure. Data suggests that microRNAs may be used to detect allograft rejection in cardiac transplantation and may predict the degree of myocardial recovery in patients with a left ventricular assist device or treated with beta-blocker therapy. Given their role in regulating cellular function, microRNAs are an intriguing target for oligonucleotide therapeutics, designed to mimic or antagonize (antagomir) their biological effects. We review the current state of microRNAs as biomarkers of heart failure and associated conditions, the mechanisms by which microRNAs control cellular function, and how specific microRNAs may be targeted with novel therapeutics designed to treat heart failure.

Self-Potential Monitoring of Landslides on Field and Laboratory Scale

Science.gov (United States)

Heinze, T.; Limbrock, J. K.; Weigand, M.; Wagner, F. M.; Kemna, A.

2017-12-01

Among several other geophysical methods used to observe water movement in the ground, the electrical self-potential method has been applied to a broad range of monitoring studies, especially focusing on volcanism and dam leakage but also during hydraulic fracturing. Electrical self-potential signals may be caused by various mechanisms. Though, the most relevant source of the self-potential field in the given context of landslides is the streaming potential, caused by a flowing electrolyte through porous media with electrically charged internal surfaces. So far, existing models focus on monitoring water flow in non-deformable porous media. However, as the self-potential is sensitive to hydraulic parameters of the soil, any change in these parameters will cause an alteration of the electric signal. Mass movement will significantly influence the hydraulic parameters of the solid as well as the pressure field, assuming that fluid movement is faster than pressure diffusion. We present self-potential measurements from over a year of continuous monitoring at an old landslide site. Using a three-dimensional electric-resistivity underground model, the self-potential signal is analyzed with respect to precipitation and the resulting flow in the ground. Additional data from electrical measurements and conventional sensors are included to assess saturation. The field observations are supplemented by laboratory experiments in which we study the behavior of the self-potential during failure of a piled land slope. For the undrained scenarios, we observe a clear correlation between the mass movements and signals in the electric potential, which clearly differ from the underlying potential variations due to increased saturation and fluid flow. In the drained experiments, we do not observe any measurable change in the electric potential. We therefore assume that change in fluid properties and release of the load causes disturbances in flow and streaming potential. Our results

Persufflation (gaseous oxygen perfusion) as a method of heart preservation.

Science.gov (United States)

Suszynski, Thomas M; Rizzari, Michael D; Scott, William E; Eckman, Peter M; Fonger, James D; John, Ranjit; Chronos, Nicolas; Tempelman, Linda A; Sutherland, David E R; Papas, Klearchos K

2013-04-22

Persufflation (PSF; gaseous oxygen perfusion) is an organ preservation technique with a potential for use in donor heart preservation. Improved heart preservation with PSF may improve outcomes by maintaining cardiac tissue quality in the setting of longer cold ischemia times and possibly increasing the number of donor hearts available for allotransplant. Published data suggests that PSF is able to extend the cold storage times for porcine hearts up to 14 hours without compromising viability and function, and has been shown to resuscitate porcine hearts following donation after cardiac death. This review summarizes key published work on heart PSF, including prospective implications and future directions for PSF in heart transplantation. We emphasize the potential impact of extending preservation times and expanding donor selection criteria in heart allotransplant. Additionally, the key issues that need to be addressed before PSF were to become a widely utilized preservation strategy prior to clinical heart transplantation are summarized and discussed.

On the relation between fields and potentials in non abelian Gauge Theories

International Nuclear Information System (INIS)

Bollini, C.G.; Giambiagi, J.J.

1979-01-01

Some examples have been given in the literature of ambiguous gauge fields, i.e. those not having a unique potential (up to a gauge transformation). An example given by Deser and Wilczek is examined and found the condition (for any gauge group) that the group element generating the potentials must satisfy in order for the potentials not to be related by any gauge transformation. In three dimensions (for Su 2 ) there are other families of ambiguous fields characterized by arbitrary unit vector fields n vector (n vector) (n 2 vector =1). The example given by Wu and Yang belongs to a particular family with n vector = n vector. r vector / r vector. The sources of these fields and some interesting relations between them are also found [pt

Description of the Magnetic Field and Divergence of Multisolenoid Aharonov-Bohm Potential

Directory of Open Access Journals (Sweden)

Araz R. Aliev

2016-01-01

Full Text Available Explicit formulas for the magnetic field and divergence of multisolenoid Aharonov-Bohm potential are obtained; the mathematical essence of this potential is explained. It is shown that the magnetic field and divergence of this potential are very singular generalized functions concentrated at a finite number of thin solenoids. Deficiency index is found for the minimal operator generated by the Aharonov-Bohm differential expression.

MIBG scintigraphy of the heart

International Nuclear Information System (INIS)

Hacker, M.; Weiss, M.

2009-01-01

The sympathetic nervous system plays an important role in cardiovascular physiology. Planar MIBG with or without SPECT can be used to visualize the sympathetic innervation of the heart and the abnormalities in innervation caused by, for example, ischemia, heart failure, and arrhythmogenic disorders. Furthermore, cardiac neuronal imaging allows early detection of autonomic neuropathy in diabetes mellitus. Assessment of sympathetic nerve activity in patients with heart failure has been shown to provide important prognostic information, and cardiac neuronal imaging can potentially identify patients who are at increased risk of sudden death. Moreover, therapeutic effects of different treatment strategies can be evaluated by imaging. To establish the clinical utility of cardiac neuronal imaging, it will be necessary to determine the incremental value of innervation imaging to triage heart failure patients to medical therapy, CRT (with or without ICD), or heart transplantation. (orig.)

Nuclear magnetic resonance imaging of the heart

International Nuclear Information System (INIS)

Smolorz, J.; Linden, A.; Schicha, H.; Sechtem, U.

1988-01-01

NMR imaging is a noninvasive technique that has been shown to provide high-quality images of the heart. Due to the signal characteristics of flowing blood, inherent contrast between blood pool and myocardium is achieved without the use of contrast media. This paper briefly describes technical aspects of NMR imaging of the heart, normal cardiovascular anatomy, applications of the technique in patients with ischemic heart disease, and the potential of NMR imaging for functional studies in various forms of heart disease. (orig.)

Heart failure with preserved ejection fraction: mechanisms, clinical features, and therapies.

Science.gov (United States)

Sharma, Kavita; Kass, David A

2014-06-20

The clinical syndrome comprising heart failure (HF) symptoms but with a left ventricular ejection fraction (EF) that is not diminished, eg, HF with preserved EF, is increasingly the predominant form of HF in the developed world, and soon to reach epidemic proportions. It remains among the most challenging of clinical syndromes for the practicing clinician and scientist alike, with a multitude of proposed mechanisms involving the heart and other organs and complex interplay with common comorbidities. Importantly, its morbidity and mortality are on par with HF with reduced EF, and as the list of failed treatments continues to grow, HF with preserved EF clearly represents a major unmet medical need. The field is greatly in need of a more unified approach to its definition and view of the syndrome that engages integrative and reserve pathophysiology beyond that related to the heart alone. We need to reflect on prior treatment failures and the message this is providing, and redirect our approaches likely with a paradigm shift in how the disease is viewed. Success will require interactions between clinicians, translational researchers, and basic physiologists. Here, we review recent translational and clinical research into HF with preserved EF and give perspectives on its evolving demographics and epidemiology, the role of multiorgan deficiencies, potential mechanisms that involve the heart and other organs, clinical trials, and future directions. © 2014 American Heart Association, Inc.

An optimized absorbing potential for ultrafast, strong-field problems

Science.gov (United States)

Yu, Youliang; Esry, B. D.

2018-05-01

Theoretical treatments of strong-field physics have long relied on the numerical solution of the time-dependent Schrödinger equation. The most effective such treatments utilize a discrete spatial representation—a grid. Since most strong-field observables relate to the continuum portion of the wave function, the boundaries of the grid—which act as hard walls and thus cause reflection—can substantially impact the observables. Special care thus needs to be taken. While there exist a number of attempts to solve this problem—e.g., complex absorbing potentials and masking functions, exterior complex scaling, and coordinate scaling—none of them are completely satisfactory. The first of these is arguably the most popular, but it consumes a substantial fraction of the computing resources in any given calculation. Worse, this fraction grows with the dimensionality of the problem. In addition, no systematic way to design such a potential has been used in the strong-field community. In this work, we address these issues and find a much better solution. By comparing with previous widely used absorbing potentials, we find a factor of 3–4 reduction in the absorption range, given the same level of absorption over a specified energy interval.

Reduced Dietary Sodium Intake Increases Heart Rate

DEFF Research Database (Denmark)

Graudal, Niels A; Hubeck-Graudal, Thorbjørn; Jürgens, Gesche

2016-01-01

Reduced dietary sodium intake (sodium reduction) increases heart rate in some studies of animals and humans. As heart rate is independently associated with the development of heart failure and increased risk of premature death a potential increase in heart rate could be a harmful side......-effect of sodium reduction. The purpose of the present meta-analysis was to investigate the effect of sodium reduction on heart rate. Relevant studies were retrieved from an updated pool of 176 randomized controlled trials (RCTs) published in the period 1973-2014. Sixty-three of the RCTs including 72 study...... populations reported data on heart rate. In a meta-analysis of these data sodium reduction increased heart rate with 1.65 beats per minute [95% CI: 1.19, 2.11], p heart rate. This effect was independent of baseline blood pressure. In conclusion sodium reduction...

Perspectives of Puerto Rican Adults about Heart Health and a Potential Community Program

Science.gov (United States)

Todorova, Irina L. G.; Tejada, Shirley; Castaneda-Sceppa, Carmen

2014-01-01

Background: Puerto Ricans are the second largest Hispanic group in the United States, and older adults have significant health disparities. Educational programs that address heart disease risk for this population have rarely been developed and implemented. Purpose: To address this gap, the Heart Healthy Initiative for Puerto Rican adults is being…

Effective potential in Lorentz-breaking field theory models

Energy Technology Data Exchange (ETDEWEB)

Baeta Scarpelli, A.P. [Centro Federal de Educacao Tecnologica, Nova Gameleira Belo Horizonte, MG (Brazil); Setor Tecnico-Cientifico, Departamento de Policia Federal, Belo Horizonte, MG (Brazil); Brito, L.C.T. [Universidade Federal de Lavras, Departamento de Fisica, Lavras, MG (Brazil); Felipe, J.C.C. [Universidade Federal de Lavras, Departamento de Fisica, Lavras, MG (Brazil); Universidade Federal dos Vales do Jequitinhonha e Mucuri, Instituto de Engenharia, Ciencia e Tecnologia, Veredas, Janauba, MG (Brazil); Nascimento, J.R.; Petrov, A.Yu. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, Paraiba (Brazil)

2017-12-15

We calculate explicitly the one-loop effective potential in different Lorentz-breaking field theory models. First, we consider a Yukawa-like theory and some examples of Lorentz-violating extensions of scalar QED. We observe, for the extended QED models, that the resulting effective potential converges to the known result in the limit in which Lorentz symmetry is restored. Besides, the one-loop corrections to the effective potential in all the cases we study depend on the background tensors responsible for the Lorentz-symmetry violation. This has consequences for physical quantities like, for example, in the induced mass due to the Coleman-Weinberg mechanism. (orig.)

Effective potential in Lorentz-breaking field theory models

International Nuclear Information System (INIS)

Baeta Scarpelli, A.P.; Brito, L.C.T.; Felipe, J.C.C.; Nascimento, J.R.; Petrov, A.Yu.

2017-01-01

We calculate explicitly the one-loop effective potential in different Lorentz-breaking field theory models. First, we consider a Yukawa-like theory and some examples of Lorentz-violating extensions of scalar QED. We observe, for the extended QED models, that the resulting effective potential converges to the known result in the limit in which Lorentz symmetry is restored. Besides, the one-loop corrections to the effective potential in all the cases we study depend on the background tensors responsible for the Lorentz-symmetry violation. This has consequences for physical quantities like, for example, in the induced mass due to the Coleman-Weinberg mechanism. (orig.)

A combined vector potential-scalar potential method for FE computation of 3D magnetic fields in electrical devices with iron cores

Science.gov (United States)

Wang, R.; Demerdash, N. A.

1991-01-01

A method of combined use of magnetic vector potential based finite-element (FE) formulations and magnetic scalar potential (MSP) based formulations for computation of three-dimensional magnetostatic fields is introduced. In this method, the curl-component of the magnetic field intensity is computed by a reduced magnetic vector potential. This field intensity forms the basic of a forcing function for a global magnetic scalar potential solution over the entire volume of the region. This method allows one to include iron portions sandwiched in between conductors within partitioned current-carrying subregions. The method is most suited for large-scale global-type 3-D magnetostatic field computations in electrical devices, and in particular rotating electric machinery.

Calcium-dependent arrhythmias in transgenic mice with heart failure.

Science.gov (United States)

London, Barry; Baker, Linda C; Lee, Joon S; Shusterman, Vladimir; Choi, Bum-Rak; Kubota, Toru; McTiernan, Charles F; Feldman, Arthur M; Salama, Guy

2003-02-01

Transgenic mice overexpressing the inflammatory cytokine tumor necrosis factor (TNF)-alpha (TNF-alpha mice) in the heart develop a progressive heart failure syndrome characterized by biventricular dilatation, decreased ejection fraction, atrial and ventricular arrhythmias on ambulatory telemetry monitoring, and decreased survival compared with nontransgenic littermates. Programmed stimulation in vitro with single extra beats elicits reentrant ventricular arrhythmias in TNF-alpha (n = 12 of 13 hearts) but not in control hearts. We performed optical mapping of voltage and Ca(2+) in isolated perfused ventricles of TNF-alpha mice to study the mechanisms that lead to the initiation and maintenance of the arrhythmias. When compared with controls, hearts from TNF-alpha mice have prolonged of action potential durations (action potential duration at 90% repolarization: 23 +/- 2 ms, n = 7, vs. 18 +/- 1 ms, n = 5; P < 0.05), no increased dispersion of refractoriness between apex and base, elevated diastolic and depressed systolic [Ca(2+)], and prolonged Ca(2+) transients (72 +/- 6 ms, n = 10, vs. 54 +/- 5 ms, n = 8; P < 0.01). Premature beats have diminished action potential amplitudes and conduct in a slow, heterogeneous manner. Lowering extracellular [Ca(2+)] normalizes conduction and prevents inducible arrhythmias. Thus both action potential prolongation and abnormal Ca(2+) handling may contribute to the initiation of reentrant arrhythmias in this heart failure model by mechanisms distinct from enhanced dispersion of refractoriness or triggered activity.

Expression of cardiac neural crest and heart genes isolated by modified differential display.

Science.gov (United States)

Martinsen, Brad J; Groebner, Nathan J; Frasier, Allison J; Lohr, Jamie L

2003-08-01

The invasion of the cardiac neural crest (CNC) into the outflow tract (OFT) and subsequent outflow tract septation are critical events during vertebrate heart development. We have performed four modified differential display screens in the chick embryo to identify genes that may be involved in CNC, OFT, secondary heart field, and heart development. The screens included differential display of RNA isolated from three different axial segments containing premigratory cranial neural crest cells; of RNA from distal outflow tract, proximal outflow tract, and atrioventricular tissue of embryonic chick hearts; and of RNA isolated from left and right cranial tissues, including the early heart fields. These screens have resulted in the identification of the five cDNA clones presented here, which are expressed in the cardiac neural crest, outflow tract and developing heart in patterns that are unique in heart development.

Valvular Heart Disease in Heart Failure

Directory of Open Access Journals (Sweden)

Giuseppe MC Rosano

2017-01-01

Full Text Available Structural valvular heart disease may be the cause of heart failure or may worsen the clinical status of patients with heart failure. Heart failure may also develop in patients treated with valve surgery. Patients with heart failure with valvular heart disease are at increased risk of events including sudden cardiac death. Before considering intervention (surgical or percutaneous all patients should receive appropriate medical and device therapy taking into account that vasodilators must be used with caution in patients with severe aortic stenosis. Numerous percutaneous and/or hybrid procedures have been introduced in the past few years and they are changing the management of valvular heart disease. In patients with heart failure and valvular heart disease, either primary or functional, the whole process of decision-making should be staged through a comprehensive evaluation of the risk– benefit ratio of different treatment strategies and should be made by a multidisciplinary ‘heart team’ with a particular expertise in valvular heart disease. The heart team should include heart failure cardiologists, cardiac surgeons/structural valve interventionists, imaging specialists, anaesthetists, geriatricians and intensive care specialists. This article will review recent developments and distill practical guidance in the management of this important heart failure co-morbidity.

Field and electric potential of conductors with fractal geometry

Energy Technology Data Exchange (ETDEWEB)

Assis, Thiago A de; Mota, Fernando de B; Miranda, Jose G V; Andrade, Roberto F S; Castilho, Caio M C de [Instituto de Fisica, Universidade Federal da Bahia, Campus Universitario da Federacao, 40210-340, Salvador (Brazil)

2007-11-28

In this study, the behavior of the electric field and its potential are investigated in a region bounded by a rough fractal surface and a distant plane. Both boundaries, maintained at distinct potential values, are assumed to be conductors and, as such, the electric potential is obtained by numerically solving Laplace's equation subject to the appropriate Dirichlet's condition. The rough boundaries, generated by the ballistic deposition and fractal Brownian motion methods, are characterized by the values of the surface roughness W and the local fractal dimension df = 3-{alpha}, where {alpha} is the usual roughness exponent. The equipotential surfaces, obtained from Laplace's equation, are characterized by these same parameters. Results presented show how df depends on the potential value, on the method used to generate the boundary and on W. The behavior of the electric field with respect to the equipotential surface is also considered. Its average intensity was found to increase as a function of the average distance from the equipotential to the fractal boundary; however, its intensity reaches a maximum before decreasing towards an asymptotic constant value, an effect that increases as the value of W increases.

Field and electric potential of conductors with fractal geometry

International Nuclear Information System (INIS)

Assis, Thiago A de; Mota, Fernando de B; Miranda, Jose G V; Andrade, Roberto F S; Castilho, Caio M C de

2007-01-01

In this study, the behavior of the electric field and its potential are investigated in a region bounded by a rough fractal surface and a distant plane. Both boundaries, maintained at distinct potential values, are assumed to be conductors and, as such, the electric potential is obtained by numerically solving Laplace's equation subject to the appropriate Dirichlet's condition. The rough boundaries, generated by the ballistic deposition and fractal Brownian motion methods, are characterized by the values of the surface roughness W and the local fractal dimension df = 3-α, where α is the usual roughness exponent. The equipotential surfaces, obtained from Laplace's equation, are characterized by these same parameters. Results presented show how df depends on the potential value, on the method used to generate the boundary and on W. The behavior of the electric field with respect to the equipotential surface is also considered. Its average intensity was found to increase as a function of the average distance from the equipotential to the fractal boundary; however, its intensity reaches a maximum before decreasing towards an asymptotic constant value, an effect that increases as the value of W increases

Investigating the Flow and Biomechanics of the Embryonic Zebrafish Heart

Science.gov (United States)

Johnson, Brennan; Garrity, Deborah; Dasi, Lakshmi

2010-11-01

Understanding flow and kinematic characteristics of the embryonic heart is a prerequisite to devise early intervention or detection methods in the context of congenital heart defects. In this study, the kinematics and fluid dynamics of the embryonic zebrafish heart were analyzed through the early stages of cardiac development (24-48 hours post-fertilization) in vivo using optical microscopy and high-speed video. Endocardial walls and individual blood cells were segmented from raw images and were tracked through the cardiac cycle. Particle tracking velocimetry analysis yielded quantitative blood cell velocity field, chamber volume, and flow rate information. It was seen that the pumping mechanism starts as a combined peristaltic and suction pump while the heart is in the tube configuration and transforms into a positive displacement pump after cardiac looping. Strong two-phase nature of the fluid is evident. This work provides us new understanding of the spatio-temporal characteristics of kinematics and blood cell velocity field inside the developing heart.

Smoking, Stress, and Coronary Heart Disease.

Science.gov (United States)

Epstein, Leonard H.; Perkins, Kenneth A.

1988-01-01

Focuses on the interrelation between stressors and smoking, and on its potential impact on coronary heart disease risk beyond that due to stressors or to smoking alone. Reviews evidence supporting the stress-smoking interrelationship, its relevance to the risk of heart disease, and mechanisms explaining why smokers smoke more during stress and why…

Olfactory Fear Conditioning Induces Field Potential Potentiation in Rat Olfactory Cortex and Amygdala

Science.gov (United States)

Messaoudi, Belkacem; Granjon, Lionel; Mouly, Anne-Marie; Sevelinges, Yannick; Gervais, Remi

2004-01-01

The widely used Pavlovian fear-conditioning paradigms used for studying the neurobiology of learning and memory have mainly used auditory cues as conditioned stimuli (CS). The present work assessed the neural network involved in olfactory fear conditioning, using olfactory bulb stimulation-induced field potential signal (EFP) as a marker of…

Tangible nanocomposites with diverse properties for heart valve application

Science.gov (United States)

Vignesh Vellayappan, Muthu; Balaji, Arunpandian; Priyadarshini Subramanian, Aruna; Aruna John, Agnes; Jaganathan, Saravana Kumar; Murugesan, Selvakumar; Mohandas, Hemanth; Supriyanto, Eko; Yusof, Mustafa

2015-06-01

Cardiovascular disease claims millions of lives every year throughout the world. Biomaterials are used widely for the treatment of this fatal disease. With the advent of nanotechnology, the use of nanocomposites has become almost inevitable in the field of biomaterials. The versatile properties of nanocomposites, such as improved durability and biocompatibility, make them an ideal choice for various biomedical applications. Among the various nanocomposites, polyhedral oligomeric silsesquioxane-poly(carbonate-urea)urethane, bacterial cellulose with polyvinyl alcohol, carbon nanotubes, graphene oxide and nano-hydroxyapatite nanocomposites have gained popularity as putative choices for biomaterials in cardiovascular applications owing to their superior properties. In this review, various studies performed utilizing these nanocomposites for improving the mechanical strength, anti-calcification potential and hemocompatibility of heart valves are reviewed and summarized. The primary motive of this work is to shed light on the emerging nanocomposites for heart valve applications. Furthermore, we aim to promote the prospects of these nanocomposites in the campaign against cardiovascular diseases.

Tangible nanocomposites with diverse properties for heart valve application

International Nuclear Information System (INIS)

Vellayappan, Muthu Vignesh; Balaji, Arunpandian; Subramanian, Aruna Priyadarshini; John, Agnes Aruna; Jaganathan, Saravana Kumar; Supriyanto, Eko; Yusof, Mustafa; Murugesan, Selvakumar; Mohandas, Hemanth

2015-01-01

Cardiovascular disease claims millions of lives every year throughout the world. Biomaterials are used widely for the treatment of this fatal disease. With the advent of nanotechnology, the use of nanocomposites has become almost inevitable in the field of biomaterials. The versatile properties of nanocomposites, such as improved durability and biocompatibility, make them an ideal choice for various biomedical applications. Among the various nanocomposites, polyhedral oligomeric silsesquioxane-poly(carbonate-urea)urethane, bacterial cellulose with polyvinyl alcohol, carbon nanotubes, graphene oxide and nano-hydroxyapatite nanocomposites have gained popularity as putative choices for biomaterials in cardiovascular applications owing to their superior properties. In this review, various studies performed utilizing these nanocomposites for improving the mechanical strength, anti-calcification potential and hemocompatibility of heart valves are reviewed and summarized. The primary motive of this work is to shed light on the emerging nanocomposites for heart valve applications. Furthermore, we aim to promote the prospects of these nanocomposites in the campaign against cardiovascular diseases. (review)

Novel experimental results in human cardiac electrophysiology: measurement of the Purkinje fibre action potential from the undiseased human heart.

Science.gov (United States)

Nagy, Norbert; Szél, Tamás; Jost, Norbert; Tóth, András; Gy Papp, Julius; Varró, András

2015-09-01

Data obtained from canine cardiac electrophysiology studies are often extrapolated to the human heart. However, it has been previously demonstrated that because of the lower density of its K(+) currents, the human ventricular action potential has a less extensive repolarization reserve. Since the relevance of canine data to the human heart has not yet been fully clarified, the aim of the present study was to determine for the first time the action potentials of undiseased human Purkinje fibres (PFs) and to compare them directly with those of dog PFs. All measurements were performed at 37 °C using the conventional microelectrode technique. At a stimulation rate of 1 Hz, the plateau potential of human PFs is more positive (8.0 ± 1.8 vs 8.6 ± 3.4 mV, n = 7), while the amplitude of the spike is less pronounced. The maximal rate of depolarization is significantly lower in human PKs than in canine PFs (406.7 ± 62 vs 643 ± 36 V/s, respectively, n = 7). We assume that the appreciable difference in the protein expression profiles of the 2 species may underlie these important disparities. Therefore, caution is advised when canine PF data are extrapolated to humans, and further experiments are required to investigate the characteristics of human PF repolarization and its possible role in arrhythmogenesis.

Potential scattering in the presence of a static magnetic field and a radiation field of arbitrary polarization

Science.gov (United States)

Ferrante, G.; Zarcone, M.; Nuzzo, S.; McDowell, M. R. C.

1982-05-01

Expressions are obtained for the total cross sections for scattering of a charged particle by a potential in the presence of a static uniform magnetic field and a radiation field of arbitrary polarization. For a Coulomb field this is closely related to the time reverse of photoionization of a neutral atom in a magnetic field, including multiphoton effects off-resonance. The model is not applicable when the radiation energy approaches one of the quasi-Landau state separations. The effects of radiation field polarization are examined in detail.

The evolution of heart gene delivery vectors

Science.gov (United States)

Wasala, Nalinda B.; Shin, Jin-Hong; Duan, Dongsheng

2012-01-01

Gene therapy holds promise for treating numerous heart diseases. A key premise for the success of cardiac gene therapy is the development of powerful gene transfer vehicles that can achieve highly efficient and persistent gene transfer specifically in the heart. Other features of an ideal vector include negligible toxicity, minimal immunogenicity and easy manufacturing. Rapid progress in the fields of molecular biology and virology has offered great opportunities to engineer various genetic materials for heart gene delivery. Several nonviral vectors (e.g. naked plasmids, plasmid lipid/polymer complexes and oligonucleotides) have been tested. Commonly used viral vectors include lentivirus, adenovirus and adeno-associated virus. Among these, adeno-associated virus has shown many attractive features for pre-clinical experimentation in animal models of heart diseases. We review the history and evolution of these vectors for heart gene transfer. PMID:21837689

Metabolic Modulators in Heart Disease: Past, Present, and Future.

Science.gov (United States)

Lopaschuk, Gary D

2017-07-01

Ischemic heart disease and heart failure are leading causes of mortality and morbidity worldwide. They continue to be major burden on health care systems throughout the world, despite major advances made over the past 40 years in developing new therapeutic approaches to treat these debilitating diseases. A potential therapeutic approach that has been underutilized in treating ischemic heart disease and heart failure is "metabolic modulation." Major alterations in myocardial energy substrate metabolism occur in ischemic heart disease and heart failure, and are associated with an energy deficit in the heart. A metabolic shift from mitochondrial oxidative metabolism to glycolysis, as well as an uncoupling between glycolysis and glucose oxidation, plays a crucial role in the development of cardiac inefficiency (oxygen consumed per work performed) and functional impairment in ischemic heart disease as well as in heart failure. This has led to the concept that optimizing energy substrate use with metabolic modulators can be a potentially promising approach to decrease the severity of ischemic heart disease and heart failure, primarily by improving cardiac efficiency. Two approaches for metabolic modulator therapy are to stimulate myocardial glucose oxidation and/or inhibit fatty acid oxidation. In this review, the past, present, and future of metabolic modulators as an approach to optimizing myocardial energy substrate metabolism and treating ischemic heart disease and heart failure are discussed. This includes a discussion of pharmacological interventions that target enzymes involved in fatty acid uptake, fatty acid oxidation, and glucose oxidation in the heart, as well as enzymes involved in ketone and branched chain amino acid catabolism in the heart. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

German disease management guidelines: surgical therapies for chronic heart failure.

Science.gov (United States)

Sindermann, J R; Klotz, S; Rahbar, K; Hoffmeier, A; Drees, G

2010-02-01

The German Disease Management Guideline "Chronic Heart Failure" intends to guide physicians working in the field of diagnosis and treatment of heart failure. The guideline provides a tool on the background of evidence based medicine. The following short review wants to give insights into the role of some surgical treatment options to improve heart failure, such as revascularization, ventricular reconstruction and aneurysmectomy, mitral valve reconstruction, ventricular assist devices and heart transplantation. (c) Georg Thieme Verlag KG Stuttgart-New York.

Heart Health - Brave Heart

Science.gov (United States)

... Bar Home Current Issue Past Issues Cover Story Heart Health Brave Heart Past Issues / Winter 2009 Table of Contents For ... you can have a good life after a heart attack." Lifestyle Changes Surviving—and thriving—after such ...

Quantum effects in external fields determined by potentials with point-like support

International Nuclear Information System (INIS)

Mamev, S.G.; Trunov, N.N.

1982-01-01

Exact expressions are obtained for the vacuum expectation values of the energy-momentum tensor of a scalar field in external potentials of the delta-function type. The conditions for the onset of the vacuum instability are found and the properties of the resulting condensate are studied. Particle production in the field of a nonstationary delta potential is studied

[Management of heart failure in cardiology and primary care (MICCAP) program: Improving the management of patients with heart failure].

Science.gov (United States)

Barrios, V; Escobar, C; Pallares, V; Egocheaga, M I; Lobos, J M; Bover, R; Gómez Doblas, J J; Cosín, J

2018-03-26

Despite current treatments, morbidity and mortality of patients with heart failure remain high. The late diagnosis of heart failure, the insufficient heart failure treatment (i.e. not using the appropriate drugs, prescribing lower doses of drugs than recommended, etc.), and a poor coordination between different health care levels, may explain, at least in part, these figures. The Management of Heart Failure in Cardiology and Primary Care (MICCAP) program has been developed with the aim of optimising the integrated management of patients with heart failure between Primary Care and Cardiology, through the improvement of coordination between both health care levels. This includes continuous medical education to reinforce the diagnostic and therapeutic skills of general practitioners in the field of heart failure. The rationale and objectives of the MICCAP program are summarised in this article. Copyright © 2018 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España, S.L.U. All rights reserved.

Analytic solution of the potential and electric field of a jet type drift chamber

Energy Technology Data Exchange (ETDEWEB)

Weltin, A

1988-02-15

Starting from the known two-dimensional potential of a multiwire proportional chamber, the analytic expressions of the potential and the electric field are derived for a jet type drift chamber with a central wire plane of alternating sense and potential wires. The design goal of any jet chamber, namely the periodicity of the electric drift field, is imposed as a boundary condition at the beginning. In this way, the formulae are short and can be easily evaluated. In particular, expressions are given for the mean potential of the central wire plane, the drift field and the wire surface fields. Moreover, wire cathodes frequently used in jet chambers are described by analytic expressions. For a given drift field the difference of the potential as compared to a continuous metal cathode is presented. These results allowed to construct a two-dimensional computer simulation of the full OPAL jet chamber with no explicit periodicity but all its boundaries. Using field shaping electrodes a geometrically short yet quite satisfactory termination of a sense wire plane is demonstrated. Finally an example is presented, which is calculated in detail.

Electric Potential and Electric Field Imaging with Dynamic Applications & Extensions

Science.gov (United States)

Generazio, Ed

2017-01-01

The technology and methods for remote quantitative imaging of electrostatic potentials and electrostatic fields in and around objects and in free space is presented. Electric field imaging (EFI) technology may be applied to characterize intrinsic or existing electric potentials and electric fields, or an externally generated electrostatic field made be used for volumes to be inspected with EFI. The baseline sensor technology (e-Sensor) and its construction, optional electric field generation (quasi-static generator), and current e- Sensor enhancements (ephemeral e-Sensor) are discussed. Critical design elements of current linear and real-time two-dimensional (2D) measurement systems are highlighted, and the development of a three dimensional (3D) EFI system is presented. Demonstrations for structural, electronic, human, and memory applications are shown. Recent work demonstrates that phonons may be used to create and annihilate electric dipoles within structures. Phonon induced dipoles are ephemeral and their polarization, strength, and location may be quantitatively characterized by EFI providing a new subsurface Phonon-EFI imaging technology. Results from real-time imaging of combustion and ion flow, and their measurement complications, will be discussed. Extensions to environment, Space and subterranean applications will be presented, and initial results for quantitative characterizing material properties are shown. A wearable EFI system has been developed by using fundamental EFI concepts. These new EFI capabilities are demonstrated to characterize electric charge distribution creating a new field of study embracing areas of interest including electrostatic discharge (ESD) mitigation, manufacturing quality control, crime scene forensics, design and materials selection for advanced sensors, combustion science, on-orbit space potential, container inspection, remote characterization of electronic circuits and level of activation, dielectric morphology of

Your heart might give away your emotions

DEFF Research Database (Denmark)

Laundav, David Kristian; Jensen, Camilla Birgitte Falk; Bækgaard, Per

2014-01-01

Estimating emotional responses to pictures based on heart rate measurements: Variations in Heart Rate serves as an important clinical health indicator, but potentially also as a window into cognitive reactions to presented stimuli, as a function of both stimuli, context and previous cognitive sta...

Extracellular Vesicles in Heart Disease: Excitement for the Future?

Directory of Open Access Journals (Sweden)

Kirsty M. Danielson

2014-01-01

Full Text Available Extracellular vesicles (EV, including exosomes, microvesicles and apoptotic bodies, are released from numerous cell types and are involved in intercellular communication, physiological functions and the pathology of disease. They have been shown to carry and transfer a wide range of cargo including proteins, lipids and nucleic acids. The role of EVs in cardiac physiology and heart disease is an emerging field that has produced intriguing findings in recent years. This review will outline what is currently known about EVs in the cardiovascular system, including cellular origins, functional roles and utility as biomarkers and potential therapeutics.

Superfield approach to calculation of effective potential in supersymmetric field theories

International Nuclear Information System (INIS)

Bukhbinder, I.L.; Kuzenko, S.M.; Yarevskaya, Zh.V.

1993-01-01

Superfield method of computing effective potential in supersymmetric field theories is suggested. The one-loop effective potential of the Wess-Zumino model is found. The prescription for obtaining multi-loop corrections is described

Foxf genes integrate tbx5 and hedgehog pathways in the second heart field for cardiac septation.

Directory of Open Access Journals (Sweden)

Andrew D Hoffmann

2014-10-01

Full Text Available The Second Heart Field (SHF has been implicated in several forms of congenital heart disease (CHD, including atrioventricular septal defects (AVSDs. Identifying the SHF gene regulatory networks required for atrioventricular septation is therefore an essential goal for understanding the molecular basis of AVSDs. We defined a SHF Hedgehog-dependent gene regulatory network using whole genome transcriptional profiling and GLI-chromatin interaction studies. The Forkhead box transcription factors Foxf1a and Foxf2 were identified as SHF Hedgehog targets. Compound haploinsufficiency for Foxf1a and Foxf2 caused atrioventricular septal defects, demonstrating the biological relevance of this regulatory network. We identified a Foxf1a cis-regulatory element that bound the Hedgehog transcriptional regulators GLI1 and GLI3 and the T-box transcription factor TBX5 in vivo. GLI1 and TBX5 synergistically activated transcription from this cis-regulatory element in vitro. This enhancer drove reproducible expression in vivo in the posterior SHF, the only region where Gli1 and Tbx5 expression overlaps. Our findings implicate Foxf genes in atrioventricular septation, describe the molecular underpinnings of the genetic interaction between Hedgehog signaling and Tbx5, and establish a molecular model for the selection of the SHF gene regulatory network for cardiac septation.

Visibility graph analysis of heart rate time series and bio-marker of congestive heart failure

Science.gov (United States)

Bhaduri, Anirban; Bhaduri, Susmita; Ghosh, Dipak

2017-09-01

Study of RR interval time series for Congestive Heart Failure had been an area of study with different methods including non-linear methods. In this article the cardiac dynamics of heart beat are explored in the light of complex network analysis, viz. visibility graph method. Heart beat (RR Interval) time series data taken from Physionet database [46, 47] belonging to two groups of subjects, diseased (congestive heart failure) (29 in number) and normal (54 in number) are analyzed with the technique. The overall results show that a quantitative parameter can significantly differentiate between the diseased subjects and the normal subjects as well as different stages of the disease. Further, the data when split into periods of around 1 hour each and analyzed separately, also shows the same consistent differences. This quantitative parameter obtained using the visibility graph analysis thereby can be used as a potential bio-marker as well as a subsequent alarm generation mechanism for predicting the onset of Congestive Heart Failure.

Thermodynamic potential with condensate fields in an SU(2) model of QCD

International Nuclear Information System (INIS)

Ebert, D.

1996-06-01

We calculate the thermodynamic potential of the quark-gluon plasma in an SU(2) model of QCD, taking into account the gluon condensate configuration with a constant A 4 -potential and a uniform chromomagnetic field H. Within this scheme the interplay of condensate fields, as well as the role of quarks in the possible dynamical stabilization of the system is investigated. (orig.)

Remote Monitoring of the Heart Condition of Athletes by Measuring the Cardiac Action Potential Propagation Time Using a Wireless Sensor Network

Directory of Open Access Journals (Sweden)

Amang Sudarsono

2016-04-01

Full Text Available Highly performing athletes are susceptible to cardiac damage of several kinds which may be irreversible. The monitoring of heart rate and ECG waveforms from such subjects by wireless sensor networks has been reported in health and sports care documents. However, a more decisive parameter for instant to instant changes would be the time of Cardiac Action Potential Propagation. This time, which can be between 15-20 ms would shoot suddenly in acute stress in highly performing athletes for short durations. Repeated incidents of such rising values will tend to cause irreversible damage to the heart. We developed the technique of measuring this time and reporting it through a wireless sensor network to monitoring station.

Application of positron emission tomography in the heart

International Nuclear Information System (INIS)

Anon.

1988-01-01

This report discusses experimental and clinical applications of positron emission tomography to the heart, including measurements of blood flow to the myocardium and studies of metabolism and experimental injury. Most initial clinical studies have concentrated on ischemic heart disease, but the technique also has potential for investigation of cardiomyopathies, studying the neural control of the heart, and evaluating the effects of drugs on cardiac tissues

Publication trends in cachexia and sarcopenia in elderly heart failure patients.

Science.gov (United States)

Springer, Jochen; Anker, Stefan D

2016-12-01

The loss of skeletal mass - sarcopenia and cachexia - is considered to be a major contributor to morbidity and mortality in chronic heart failure (CHF). Unfortunately, sarcopenia is generally considered to be a geriatric syndrome, but not necessarily seen as a comorbidity in CHF, even though it has a wide range of adverse health outcomes. While there were 15,574 publication with the title word "heart failure" in PubMed in the 5‑year period from 1 June 2011 to 31 May 2016, only 22 or 71 publications were found with the search combination "sarcopenia" or "cachexia" (title word) and "heart failure" (all fields), respectively. This shows very clearly that loss of muscle quality and function due to heart failure is still an underappreciated problem in the medical field.

FPGA Implementation of Heart Rate Monitoring System.

Science.gov (United States)

Panigrahy, D; Rakshit, M; Sahu, P K

2016-03-01

This paper describes a field programmable gate array (FPGA) implementation of a system that calculates the heart rate from Electrocardiogram (ECG) signal. After heart rate calculation, tachycardia, bradycardia or normal heart rate can easily be detected. ECG is a diagnosis tool routinely used to access the electrical activities and muscular function of the heart. Heart rate is calculated by detecting the R peaks from the ECG signal. To provide a portable and the continuous heart rate monitoring system for patients using ECG, needs a dedicated hardware. FPGA provides easy testability, allows faster implementation and verification option for implementing a new design. We have proposed a five-stage based methodology by using basic VHDL blocks like addition, multiplication and data conversion (real to the fixed point and vice-versa). Our proposed heart rate calculation (R-peak detection) method has been validated, using 48 first channel ECG records of the MIT-BIH arrhythmia database. It shows an accuracy of 99.84%, the sensitivity of 99.94% and the positive predictive value of 99.89%. Our proposed method outperforms other well-known methods in case of pathological ECG signals and successfully implemented in FPGA.

Hypoplastic left heart syndrome - a review of supportive percutaneous treatment.

Science.gov (United States)

Moszura, Tomasz; Góreczny, Sebastian; Dryżek, Paweł

2014-01-01

Due to the complex anatomical and haemodynamic consequences of hypoplastic left heart syndrome (HLHS), patients with the condition require multistage surgical and supportive interventional treatment. Percutaneous interventions may be required between each stage of surgical palliation, sometimes simultaneously with surgery as hybrid interventions, or after completion of multistage treatment. Recent advances in the field of interventional cardiology, including new devices and techniques, have significantly contributed to improving results of multistage HLHS palliation. Knowledge of the potential interventional options as well as the limitation of percutaneous interventions will enable the creation of safe and effective treatment protocols in this highly challenging group of patients. In this comprehensive review we discuss the types, goals, and potential complications of transcatheter interventions in patients with HLHS.

Potential of the test particle in the magnetic field. I

International Nuclear Information System (INIS)

Sestak, B.

1980-01-01

The problem of the test particle potential in an external homogeneous magnetic field is solved in an unmagnetized plasma. It is shown that for the case when the parallel velocity component of the test particle is greater than the thermal velocity of the background particles, the potential is of a Coulomb character while for the case where the parallel velocity component is less than the thermal velocity the potential is of a Debye character. The Larmor radius of the test particle appears as an additional parameter in these potentials. (author)

Separation of Electric Fields Into Potential and Inductive Parts, and Implications for Radial Diffusion

Science.gov (United States)

Chan, A. A.; Ilie, R.; Elkington, S. R.; Albert, J.; Huie, W.

2017-12-01

It has been traditional to separate radiation belt radial-diffusion coefficients into two contributions: an "electrostatic" diffusion coefficient, which is assumed to be due to a potential (non-inductive) electric field, and an "electromagnetic" diffusion coefficient , which is assumed to be due to the combined effect of an inductive electric field and the corresponding time-dependent magnetic field. One difficulty in implementing this separation when using magnetospheric fields obtained from measurements, or from MHD simulations, is that only the total electric field is given; the separation of the electric field into potential and inductive parts is not readily available. In this work we separate the electric field using a numerical method based on the Helmholtz decomposition of the total motional electric field calculated by the BATS-R-US MHD code. The inner boundary for the electric potential is based on the Ridley Ionospheric Model solution and we assume floating boundary conditions in the solar wind. Using different idealized solar wind drivers, including a solar wind density that is oscillating at a single frequency or with a broad spectrum of frequencies, we calculate potential and inductive electric fields, electric and magnetic power spectral densities, and corresponding radial diffusion coefficients. Simulations driven by idealized solar wind conditions show a clear separation of the potential and inductive contributions to the power spectral densities and diffusion coefficients. Simulations with more realistic solar wind drivers are underway to better assess the use of electrostatic and electromagnetic diffusion coefficients in understanding ULF wave-particle interactions in Earth's radiation belts.

Ionization from short-range potential under action of electromagnetic field of complex configuration

CERN Document Server

Rodionov, V N; Kravtsova, G A

2002-01-01

The transcendental equation for the complex energy is obtained on the basis of the exactly solvable 3D model of the short-acting potential and the Green time function in the intensive electromagnetic field, constituting the combination of the constant magnetic field and the circular-polarization wave field. The electron quasistationary states parameters in the delta-potential with an account of the action of the intensive external field of complex configuration are calculated. The problem on the possibility of stabilizing the bound states decay of the spinor and scalar particles through the intensive magnetic field is clarified. It is established that the obtained results regime the reexamination of the accepted notion on the stabilizing role of the strong magnetic field by the atoms ionization

"Mobile technology to improve heart failure outcomes: A proof of concept paper".

Science.gov (United States)

Athilingam, Ponrathi; Jenkins, Bradlee A; Zumpano, Heather; Labrador, Miguel A

2018-02-01

Heart failure (HF) causes significant symptom burden and human suffering with considerable economic burden due to hospital readmissions. Targeted interventions to encourage and support self-management behavior is warranted. To test the proof of concept of a mobile application (HeartMapp) in improving self-care management of patients with heart failure. An exploratory inquiry used a field study strategy with purposeful sampling and constant comparative analysis to test the proof of concept of HeartMapp using The Business Model Canvas framework. A total of 125 individuals, who were identified as potential candidates to use the HeartMapp completed the interview over a seven-week period in 2016. Constant comparative analysis indicated themes that Skilled Nursing Facilities had increased readmissions. Participants from Skilled Nursing Facilities reported concern on lack of staffing, star rating, and malpractice claims. Two types of patients were identified as early adapters of technology and those in denial. Health care facilities reported challenges on transitional care, nurses struggle with engagement of patients on self-care management. To avoid readmission penalty, hospitals task home care agencies to keep the patients home for 30-days. While home care agencies rely on remote telemonitoring reported that current telemonitoring devices are costly to maintain, thus exploring novel technology. The Business Model Canvas provided directions for future testing of HeartMapp for its usability as an adjunct device in home health setting to improve self-management and enhance communication with providers, and ultimately reduce readmissions. Copyright © 2017 Elsevier Inc. All rights reserved.

Recent clinical trials in valvular heart disease.

Science.gov (United States)

Kiss, Daniel; Anwaruddin, Saif

2017-07-01

With widespread adoption of transcatheter aortic valve replacement, there has been a change in the approach to management of valvular heart disease. New interest has taken hold in transcatheter therapies for valvular heart disease, as well as research into pathophysiology and progression of disease. Additionally, several key trials have further refined our understanding of surgical management of valvular heart disease. This review will elucidate recent clinical trial data leading to changes in practice. There have been several landmark trials expanding the indications for transcatheter aortic valve replacement. Additionally, although still early, trials are beginning to demonstrate the feasibility and safety of transcatheter mitral valves. Options for transcatheter management of right-sided valvular disease continue to evolve, and these are areas of active investigation. The emergence of novel therapies for valvular heart disease has expanded the management options available, allowing physicians to better individualize treatment of patients with valvular heart disease. This review will focus on the recent (within 2 years) trials in this field of interest.

Myoblast transplantation for heart repair: A review of the state of the field

Institute of Scientific and Technical Information of China (English)

Howard J. Leonhardt; Michael Brown

2006-01-01

Over 200 humans have been treated with myoblast transplantation for heart muscle repair since June 2000. Bioheart sponsored percutaneous delivery studies began in May 2001 in Europe. Approximately one third of the patients have exhibited substantial improvement in left ventricular ejection fraction (LVEF) of over 30% and two heart failure class improvements. Over 80% of the patients have exhibited one heart failure class improvement with moderate improvement of LVEF. Clinical trials seem to demonstrate a marked reduction in emergency hospitalizations in myoblast treated patients. Many years of careful studies have lead to randomized controlled studies that are enrolling patients now at numerous centers worldwide. A firm conclusion on the safety and efficacy of myoblast transplantation cannot be determined until these randomized studies are completed. Final results from randomized controlled studies should be available soon. (J Geriatr Cardiol 2006;3:165-7.)

[Definition of acute heart failure].

Science.gov (United States)

Metra, Marco; Carbone, Giorgio; Lombardi, Carlo; Borghi, Claudio; Vescovo, Giorgio

2014-02-01

Acute heart failure (AHF) is a potentially life-threatening condition that may arise as a deterioration of a previous heart failure or may be the first presentation of heart failure. Several causes or precipitating factors have been listed, as well as different mechanisms have been described, thus leading to a broad spectrum of clinical presentations. Symptoms and signs of AHF have a strong clinical and prognostic significance and are kept into consideration to guide disease management. In particular, a higher clinical severity or a worse prognosis are associated with lower blood pressure levels, fluid overload, evidence of myocardial ischemia or renal impairment. Putatively, interventions addressed to restore these factors may play a role in the management of AHF.

3D velocity field characterization of prosthetic heart valve with two different valve testers by means of stereo-PIV.

Science.gov (United States)

D'Avenio, Giuseppe; Grigioni, Mauro; Daniele, Carla; Morbiducci, Umberto; Hamilton, Kathrin

2015-01-01

Prosthetic heart valves can be associated to mechanical loading of blood, potentially linked to complications (hemolysis and thrombogenicity) which can be clinically relevant. In order to test such devices in pulsatile mode, pulse duplicators (PDs) have been designed and built according to different concepts. This study was carried out to compare anemometric measurements made on the same prosthetic device, with two widely used PDs. The valve (a 27-mm bileaflet valve) was mounted in the aortic section of the PD. The Sheffield University PD and the RWTH Aachen PD were selected as physical models of the circulation. These two PDs differ mainly in the vertical vs horizontal realization, and in the ventricular section, which in the RWTH PD allows for storage of potential energy in the elastic walls of the ventricle. A glassblown aorta, realized according to the geometric data of the same anatomical district in healthy individuals, was positioned downstream of the valve, obtaining 1:1 geometric similarity conditions. A NaI-glycerol-water solution of suitable kinematic viscosity and, at the same time, the proper refractive index, was selected. The flow field downstream of the valve was measured by means of the stereo-PIV (Particle Image Velocimetry) technique, capable of providing the complete 3D velocity field as well as the entire Reynolds stress tensor. The measurements were carried out at the plane intersecting the valve axis. A three-jet profile was clearly found in the plane crossing the leaflets, with both PDs. The extent of the typical recirculation zone in the Valsalva sinus was much larger in the RWTH PD, on account of the different duration of the swirling motion in the ventricular chamber, caused by the elasticity of the ventricle and its geometry. The comparison of the hemodynamical behaviour of the same bileaflet valve tested in two PDs demonstrated the role of the mock loop in affecting the valve performance.

Field differential equations for a potential flow from a Hamilton type variational principle

International Nuclear Information System (INIS)

Fierros Palacios, A.

1992-01-01

The same theoretical frame that was used to solve the problem of the field equations for a viscous fluid is utilized in this work. The purpose is to obtain the differential field equations for a potential flow from the Lagrangian formalism as in classical field theory. An action functional is introduced as a space-time integral over a region of three-dimensional Euclidean space, of a Lagrangian density as a function of certain field variables. A Hamilton type extremum action principle is postulated with adequate boundary conditions, and a set of differential field equations is derived. A particular Lagrangian density of the T-V type leads to the wave equation for the velocity potential. (Author)

Mean Field Limits for Interacting Diffusions in a Two-Scale Potential

Science.gov (United States)

Gomes, S. N.; Pavliotis, G. A.

2018-06-01

In this paper, we study the combined mean field and homogenization limits for a system of weakly interacting diffusions moving in a two-scale, locally periodic confining potential, of the form considered in Duncan et al. (Brownian motion in an N-scale periodic potential, arXiv:1605.05854, 2016b). We show that, although the mean field and homogenization limits commute for finite times, they do not, in general, commute in the long time limit. In particular, the bifurcation diagrams for the stationary states can be different depending on the order with which we take the two limits. Furthermore, we construct the bifurcation diagram for the stationary McKean-Vlasov equation in a two-scale potential, before passing to the homogenization limit, and we analyze the effect of the multiple local minima in the confining potential on the number and the stability of stationary solutions.

An open-access mobile compatible electronic patient register for rheumatic heart disease (‘eRegister’) based on the World Heart Federation’s framework for patient registers

Science.gov (United States)

van Dam, Joris; Tadmor, Brigitta; Spector, Jonathan; Musuku, John; Zühlke, Liesl J; Zühlke, Liesl J; Engel, Mark E; Mayosi, Bongani M; Nestle, Nick

2015-01-01

Summary Background Rheumatic heart disease (RHD) remains a major disease burden in low-resource settings globally. Patient registers have long been recognised to be an essential instrument in RHD control and elimination programmes, yet to date rely heavily on paper-based data collection and non-networked data-management systems, which limit their functionality. Objectives To assess the feasibility and potential benefits of producing an electronic RHD patient register. Methods We developed an eRegister based on the World Heart Federation’s framework for RHD patient registers using CommCare, an open-source, cloud-based software for health programmes that supports the development of customised data capture using mobile devices. Results The resulting eRegistry application allows for simultaneous data collection and entry by field workers using mobile devices, and by providers using computer terminals in clinics and hospitals. Data are extracted from CommCare and are securely uploaded into a cloud-based database that matches the criteria established by the WHF framework. The application can easily be tailored to local needs by modifying existing variables or adding new ones. Compared with traditional paper-based data-collection systems, the eRegister reduces the risk of data error, synchronises in real-time, improves clinical operations and supports management of field team operations. Conclusions The user-friendly eRegister is a low-cost, mobile, compatible platform for RHD treatment and prevention programmes based on materials sanctioned by the World Heart Federation. Readily adaptable to local needs, this paperless RHD patient register program presents many practical benefits. PMID:26444995

Epicardium-Derived Heart Repair

Directory of Open Access Journals (Sweden)

Anke M. Smits

2014-04-01

Full Text Available In the last decade, cell replacement therapy has emerged as a potential approach to treat patients suffering from myocardial infarction (MI. The transplantation or local stimulation of progenitor cells with the ability to form new cardiac tissue provides a novel strategy to overcome the massive loss of myocardium after MI. In this regard the epicardium, the outer layer of the heart, is a tractable local progenitor cell population for therapeutic pursuit. The epicardium has a crucial role in formation of the embryonic heart. After activation and migration into the developing myocardium, epicardial cells differentiate into several cardiac cells types. Additionally, the epicardium provides instructive signals for the growth of the myocardium and coronary angiogenesis. In the adult heart, the epicardium is quiescent, but recent evidence suggests that it becomes reactivated upon damage and recapitulates at least part of its embryonic functions. In this review we provide an update on the current knowledge regarding the contribution of epicardial cells to the adult mammalian heart during the injury response.

ESC Working Group on Valvular Heart Disease position paper--heart valve clinics: organization, structure, and experiences.

Science.gov (United States)

Lancellotti, Patrizio; Rosenhek, Raphael; Pibarot, Philippe; Iung, Bernard; Otto, Catherine M; Tornos, Pilar; Donal, Erwan; Prendergast, Bernard; Magne, Julien; La Canna, Giovanni; Piérard, Luc A; Maurer, Gerald

2013-06-01

With an increasing prevalence of patients with valvular heart disease (VHD), a dedicated management approach is needed. The challenges encountered are manifold and include appropriate diagnosis and quantification of valve lesion, organization of adequate follow-up, and making the right management decisions, in particular with regard to the timing and choice of interventions. Data from the Euro Heart Survey have shown a substantial discrepancy between guidelines and clinical practice in the field of VHD and many patients are denied surgery despite having clear indications. The concept of heart valve clinics (HVCs) is increasingly recognized as the way to proceed. At the same time, very few centres have developed such expertise, indicating that specific recommendations for the initial development and subsequent operating requirements of an HVC are needed. The aim of this position paper is to provide insights into the rationale, organization, structure, and expertise needed to establish and operate an HVC. Although the main goal is to improve the clinical management of patients with VHD, the impact of HVCs on education is of particular importance: larger patient volumes foster the required expertise among more senior physicians but are also fundamental for training new cardiologists, medical students, and nurses. Additional benefits arise from research opportunities resulting from such an organized structure and the delivery of standardized care protocols. The growing volume of patients with VHD, their changing characteristics, and the growing technological opportunities of refined diagnosis and treatment in addition to the potential dismal prognosis if overlooked mandate specialized evaluation and care by dedicated physicians working in a specialized environment that is called the HVC.

Potential Magnetic Field around a Helical Flux-rope Current Structure in the Solar Corona

OpenAIRE

Petrie, G. J. D.

2007-01-01

We consider the potential magnetic field associated with a helical electric line current flow, idealizing the near-potential coronal field within which a highly localized twisted current structure is embedded. It is found that this field has a significant axial component off the helical magnetic axis where there is no current flow, such that the flux winds around the axis. The helical line current field, in including the effects of flux rope writhe, is therefore more topologically complex tha...

Potential clinical relevance of the 'little brain' on the mammalian heart.

Science.gov (United States)

Armour, J A

2008-02-01

It is hypothesized that the heart possesses a nervous system intrinsic to it that represents the final relay station for the co-ordination of regional cardiac indices. This 'little brain' on the heart is comprised of spatially distributed sensory (afferent), interconnecting (local circuit) and motor (adrenergic and cholinergic efferent) neurones that communicate with others in intrathoracic extracardiac ganglia, all under the tonic influence of central neuronal command and circulating catecholamines. Neurones residing from the level of the heart to the insular cortex form temporally dependent reflexes that control overlapping, spatially determined cardiac indices. The emergent properties that most of its components display depend primarily on sensory transduction of the cardiovascular milieu. It is further hypothesized that the stochastic nature of such neuronal interactions represents a stabilizing feature that matches cardiac output to normal corporal blood flow demands. Thus, with regard to cardiac disease states, one must consider not only cardiac myocyte dysfunction but also the fact that components within this neuroaxis may interact abnormally to alter myocyte function. This review emphasizes the stochastic behaviour displayed by most peripheral cardiac neurones, which appears to be a consequence of their predominant cardiac chemosensory inputs, as well as their complex functional interconnectivity. Despite our limited understanding of the whole, current data indicate that the emergent properties displayed by most neurones comprising the cardiac neuroaxis will have to be taken into consideration when contemplating the targeting of its individual components if predictable, long-term therapeutic benefits are to accrue.

Primordial black holes from polynomial potentials in single field inflation

Science.gov (United States)

Hertzberg, Mark P.; Yamada, Masaki

2018-04-01

Within canonical single field inflation models, we provide a method to reverse engineer and reconstruct the inflaton potential from a given power spectrum. This is not only a useful tool to find a potential from observational constraints, but also gives insight into how to generate a large amplitude spike in density perturbations, especially those that may lead to primordial black holes (PBHs). In accord with other works, we find that the usual slow-roll conditions need to be violated in order to generate a significant spike in the spectrum. We find that a way to achieve a very large amplitude spike in single field models is for the classical roll of the inflaton to overshoot a local minimum during inflation. We provide an example of a quintic polynomial potential that implements this idea and leads to the observed spectral index, observed amplitude of fluctuations on large scales, significant PBH formation on small scales, and is compatible with other observational constraints. We quantify how much fine-tuning is required to achieve this in a family of random polynomial potentials, which may be useful to estimate the probability of PBH formation in the string landscape.

Cell migration during heart regeneration in zebrafish.

Science.gov (United States)

Tahara, Naoyuki; Brush, Michael; Kawakami, Yasuhiko

2016-07-01

Zebrafish possess the remarkable ability to regenerate injured hearts as adults, which contrasts the very limited ability in mammals. Although very limited, mammalian hearts do in fact have measurable levels of cardiomyocyte regeneration. Therefore, elucidating mechanisms of zebrafish heart regeneration would provide information of naturally occurring regeneration to potentially apply to mammalian studies, in addition to addressing this biologically interesting phenomenon in itself. Studies over the past 13 years have identified processes and mechanisms of heart regeneration in zebrafish. After heart injury, pre-existing cardiomyocytes dedifferentiate, enter the cell cycle, and repair the injured myocardium. This process requires interaction with epicardial cells, endocardial cells, and vascular endothelial cells. Epicardial cells envelope the heart, while endocardial cells make up the inner lining of the heart. They provide paracrine signals to cardiomyocytes to regenerate the injured myocardium, which is vascularized during heart regeneration. In addition, accumulating results suggest that local migration of these major cardiac cell types have roles in heart regeneration. In this review, we summarize the characteristics of various heart injury methods used in the research community and regeneration of the major cardiac cell types. Then, we discuss local migration of these cardiac cell types and immune cells during heart regeneration. Developmental Dynamics 245:774-787, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Right heart dysfunction and failure in heart failure with preserved ejection fraction: mechanisms and management. Position statement on behalf of the Heart Failure Association of the European Society of Cardiology.

Science.gov (United States)

Gorter, Thomas M; van Veldhuisen, Dirk J; Bauersachs, Johann; Borlaug, Barry A; Celutkiene, Jelena; Coats, Andrew J S; Crespo-Leiro, Marisa G; Guazzi, Marco; Harjola, Veli-Pekka; Heymans, Stephane; Hill, Loreena; Lainscak, Mitja; Lam, Carolyn S P; Lund, Lars H; Lyon, Alexander R; Mebazaa, Alexandre; Mueller, Christian; Paulus, Walter J; Pieske, Burkert; Piepoli, Massimo F; Ruschitzka, Frank; Rutten, Frans H; Seferovic, Petar M; Solomon, Scott D; Shah, Sanjiv J; Triposkiadis, Filippos; Wachter, Rolf; Tschöpe, Carsten; de Boer, Rudolf A

2018-01-01

There is an unmet need for effective treatment strategies to reduce morbidity and mortality in patients with heart failure with preserved ejection fraction (HFpEF). Until recently, attention in patients with HFpEF was almost exclusively focused on the left side. However, it is now increasingly recognized that right heart dysfunction is common and contributes importantly to poor prognosis in HFpEF. More insights into the development of right heart dysfunction in HFpEF may aid to our knowledge about this complex disease and may eventually lead to better treatments to improve outcomes in these patients. In this position paper from the Heart Failure Association of the European Society of Cardiology, the Committee on Heart Failure with Preserved Ejection Fraction reviews the prevalence, diagnosis, and pathophysiology of right heart dysfunction and failure in patients with HFpEF. Finally, potential treatment strategies, important knowledge gaps and future directions regarding the right side in HFpEF are discussed. © 2017 The Authors. European Journal of Heart Failure © 2017 European Society of Cardiology.

Validity of the Elite HRV Smartphone Application for Examining Heart Rate Variability in a Field-Based Setting.

Science.gov (United States)

Perrotta, Andrew S; Jeklin, Andrew T; Hives, Ben A; Meanwell, Leah E; Warburton, Darren E R

2017-08-01

Perrotta, AS, Jeklin, AT, Hives, BA, Meanwell, LE, and Warburton, DER. Validity of the elite HRV smartphone application for examining heart rate variability in a field-based setting. J Strength Cond Res 31(8): 2296-2302, 2017-The introduction of smartphone applications has allowed athletes and practitioners to record and store R-R intervals on smartphones for immediate heart rate variability (HRV) analysis. This user-friendly option should be validated in the effort to provide practitioners confidence when monitoring their athletes before implementing such equipment. The objective of this investigation was to examine the relationship and validity between a vagal-related HRV index, rMSSD, when derived from a smartphone application accessible with most operating systems against a frequently used computer software program, Kubios HRV 2.2. R-R intervals were recorded immediately upon awakening over 14 consecutive days using the Elite HRV smartphone application. R-R recordings were then exported into Kubios HRV 2.2 for analysis. The relationship and levels of agreement between rMSSDln derived from Elite HRV and Kubios HRV 2.2 was examined using a Pearson product-moment correlation and a Bland-Altman Plot. An extremely large relationship was identified (r = 0.92; p smartphone HRV application may offer a reliable platform when assessing parasympathetic modulation.

Comparison of potential field solutions for Carrington Rotation 2144

Science.gov (United States)

Hayashi, Keiji; Yang, Shangbin; Deng, Yuagyong

2016-02-01

We examined differences among the coronal magnetic field structures derived with the potential field source surface (PFSS) model for Carrington Rotation 2144, from 21 November to 19 December 2013. We used the synoptic maps of solar photospheric magnetic field from four observatories, the Huairou Solar Observing Station (HSOS), Global Oscillation Network Group (GONG), Helioseismic Magnetic Imager (HMI), and Wilcox Solar Observatory (WSO). We tested two smoothing methods, Gaussian and boxcar averaging, and correction of unbalanced net magnetic flux. The solutions of three-dimensional coronal magnetic field are significantly different each other. An open-field region derived with HSOS data agrees best with the corresponding coronal hole observed by Solar Dynamics Observatories/Atmospheric Imaging Assembly, while HMI data yielded best agreements with the near-Earth OMNI database. The GONG data overall gave agreements as good as the HMI. The PFSS calculations using WSO data were least sensitive to the choices we examined in this work. Differences in PFSS solutions using different choices and parameters in smoothing imply that the photospheric magnetic field distributions with size of several degrees at midlatitude and low-latitude regions can be decisive, at least, in the examined period. To better determine the global solar corona, therefore, further evaluation of influences from compact bipolar magnetic field is needed.

Flat structure and potential vector fields related with algebraic solutions to Painlevé VI equation

Directory of Open Access Journals (Sweden)

Mitsuo Kato

2018-01-01

Full Text Available A potential vector field is a solution of an extended WDVV equation which is a generalization of a WDVV equation. It is expected that potential vector fields corresponding to algebraic solutions of Painlevé VI equation can be written by using polynomials or algebraic functions explicitly. The purpose of this paper is to construct potential vector fields corresponding to more than thirty non-equivalent algebraic solutions.

System overview of the fully implantable destination therapy--ReinHeart-total artificial heart.

Science.gov (United States)

Pelletier, Benedikt; Spiliopoulos, Sotirios; Finocchiaro, Thomas; Graef, Felix; Kuipers, Kristin; Laumen, Marco; Guersoy, Dilek; Steinseifer, Ulrich; Koerfer, Reiner; Tenderich, Gero

2015-01-01

Owing to the lack of suitable allografts, the demand for long-term mechanical circulatory support in patients with biventricular end-stage heart failure is rising. Currently available Total Artificial Heart (TAH) systems consist of pump units with only limited durability, percutaneous tubes and bulky external equipment that limit the quality of life. Therefore we are focusing on the development of a fully implantable, highly durable destination therapy total artificial heart. The ReinHeart-TAH system consists of a passively filling pump unit driven by a low-wear linear drive between two artificial ventricles, an implantable control unit and a compliance chamber. The TAH is powered by a transcutaneous energy transmission system. The flow distribution inside the ventricles was analysed by fluid structure interaction simulation and particle image velocimetry measurements. Along with durability tests, the hydrodynamic performance and flow balance capability were evaluated in a mock circulation loop. Animal trials are ongoing. Based on fluid structure interaction simulation and particle image velocimetry, blood stagnation areas have been significantly reduced. In the mock circulation loop the ReinHeart-TAH generated a cardiac output of 5 l/min at an operating frequency of 120 bpm and an aortic pressure of 120/80 mmHg. The highly effective preload sensitivity of the passively filling ventricles allowed the sensorless integration of the Frank Starling mechanism. The ReinHeart-TAH effectively replaced the native heart's function in animals for up to 2 days. In vitro and in vivo testing showed a safe and effective function of the ReinHeart-TAH system. This has the potential to become an alternative to transplantation. However, before a first-in-man implant, chronic animal trials still have to be completed. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

[Atrial fibrillation concomitant with valvular heart disease].

Science.gov (United States)

Ishii, Yosuke

2013-01-01

Patients with valvular heart disease frequently have atrial fibrillation(AF) due to elevated pressure and dilatation of the left and right atria and pulmonary veins. Guidelines for valvular heart disease and AF recommend that surgical treatment for the valvular heart disease should be performed concomitantly with AF surgery. The Full-Maze procedure has evolved into the gold standard of treatment for medically refractory AF. In addition to the pulmonary vein isolation, the right and left atrial incisions of the Full-Maze procedure are designed to block potential macroreentrant pathways. According to the mechanisms of AF with valvular heart disease, the Full-Maze procedure is more effective for the patients than the pulmonary vein isolation alone.

Preattentive processing of heart cues and the perception of heart symptoms in congenital heart disease.

Science.gov (United States)

Karsdorp, Petra A; Kindt, Merel; Everaerd, Walter; Mulder, Barbara J M

2007-08-01

The present study was aimed at clarifying whether preattentive processing of heart cues results in biased perception of heart sensations in patients with congenital heart disease (ConHD) who are also highly trait anxious. Twenty-six patients with ConHD and 22 healthy participants categorized heart-related (heart rate) or neutral sensations (constant vibration) as either heart or neutral. Both sensations were evoked using a bass speaker that was attached on the chest of the participant. Before each physical sensation, a subliminal heart-related or neutral prime was presented. Biased perception of heart-sensations would become evident by a delayed categorization of the heart-related sensations. In line with the prediction, a combination of high trait anxiety and ConHD resulted in slower responses after a heart-related sensation that was preceded by a subliminal heart cue. Preattentive processing of harmless heart cues may easily elicit overperception of heart symptoms in highly trait anxious patients with ConHD.

A peripheral blood transcriptome biomarker test to diagnose functional recovery potential in advanced heart failure.

Science.gov (United States)

Deng, Mario C

2018-05-08

Heart failure (HF) is a complex clinical syndrome that causes systemic hypoperfusion and failure to meet the body's metabolic demands. In an attempt to compensate, chronic upregulation of the sympathetic nervous system and renin-angiotensin-aldosterone leads to further myocardial injury, HF progression and reduced O 2 delivery. This triggers progressive organ dysfunction, immune system activation and profound metabolic derangements, creating a milieu similar to other chronic systemic diseases and presenting as advanced HF with severely limited prognosis. We hypothesize that 1-year survival in advanced HF is linked to functional recovery potential (FRP), a novel clinical composite parameter that includes HF severity, secondary organ dysfunction, co-morbidities, frailty, disabilities as well as chronological age and that can be diagnosed by a molecular biomarker.

Localization of heart vectors produced by epicardial burns and ectopic stimuli; validation of a dipole ranging method.

Science.gov (United States)

Ideker, R E; Bandura, J P; Larsen, R A; Cox, J W; Keller, F W; Brody, D A

1975-01-01

Location of the equivalent cardiac dipole has been estimated but not fully verified in several laboratories. To test the accuracy of such a procedure, injury vectors were produced in 14 isolated, perfused rabbit hearts by epicardial searing. Strongly dipolar excitation fronts were produced in 6 additional hearts by left ventricular pacing. Twenty computer-processed signals, derived from surface electrodes on a spherical electrolyte-filled tank containing the test preparation, were optimally fitted with a locatable cardiac dipole that accounted for over 99% of the root-mean-square surface potential. For the 14 burns (mean radius 5.0 mm), the S-T injury dipole was located 3.4 plus or minus 0.7 (SD) mm from the burn center. For the 6 paced hearts, the dipole early in the ectopic beat was located 3.7 mm (range 2.6 to 4.6 mm) from the stimulating electrode. Phase inhomogeneities within the chamber appeared to have a small but predictable effect on dipole site determination. The study demonstrates that equivalent dipole location can be determined with acceptable accuracy from potential measurements of the external cardiac field.

Acoustic heart. Interpretation of Phonocardiograms by computer

International Nuclear Information System (INIS)

Granados, J; Tavera, F; Velázquez, J M; Hernández, R T; Morales, A; López, G

2015-01-01

In the field of Cardiology have been identified several heart pathologies associated with problems in valves and narrowing in veins. Each case is associated with a specific sound emitted by the heart, detected in cardiac auscultation. On the Phonocardiogram, sound is visualized as a peak in the wave. In the Optics Laboratory of the Universidad Autonoma Metropolitana – Azcapotzalco, we have developed a simulation of the Phonocardiograms of heart sounds associated with the main pathologies and a computer program of recognition of images that allows you to quickly identify the respective diseases. This is a novel way to analyze Phonocardiograms and the foundation for building a portable non-invasive cardiac diagnostic computerized analyzer system

Intense laser field effects on a Woods-Saxon potential quantum well

Science.gov (United States)

Restrepo, R. L.; Morales, A. L.; Akimov, V.; Tulupenko, V.; Kasapoglu, E.; Ungan, F.; Duque, C. A.

2015-11-01

This paper presents the results of the theoretical study of the effects of non-resonant intense laser field and electric and magnetic fields on the optical properties in an quantum well (QW) make with Woods-Saxon potential profile. The electric field and intense laser field are applied along the growth direction of the Woods-Saxon quantum well and the magnetic field is oriented perpendicularly. To calculate the energy and the wave functions of the electron in the Woods-Saxon quantum well, the effective mass approximation and the method of envelope wave function are used. The confinement in the Woods-Saxon quantum well is changed drastically by the application of intense laser field or either the effect of electric and magnetic fields. The optical properties are calculated using the compact density matrix.

Sum rules for the ed - NN scattering reactions and microscopic potential field-theoretical approach

International Nuclear Information System (INIS)

Machivariani, A.I.

1996-01-01

The connections between the equal-time commutators of nucleon and photon field-operators and relativistic potential approach of ed - NN scattering equations is established. Namely, it is demonstrated that: 1) equal-time commutator between nucleon field operators generated completeness condition for NN interaction functions, 2) the off-mass shell contributions in γd - NN exchange currents or in microscopic NN potential are determined by equal time commutator between nucleon field operator and photon or nucleon source operators, and 3) equal-time commutators between source operators produce sum rules for same vertex functions and effective potentials [ru

Severe right heart failure in a patient with Grave's disease.

Science.gov (United States)

Xenopoulos, N P; Braden, G A; Applegate, R J

1996-11-01

This brief report presents a patient with isolated right heart failure and two rare underlying causes, hyperthyroidism and dysplastic tricuspid valve. Repair of the tricuspid valve and treatment of the hyperthyroidism were both essential for successful treatment of the right heart failure. Most important, recrudescence of hyperthyroidism in this patient was associated with reappearance of florid right heart failure. This report provides further information about a potential linkage of hyperthyroidism and severe right heart failure.

A physics-based potential and electric field model of a nanoscale ...

Indian Academy of Sciences (India)

... paper, we have developed a physics-based model for surface potential, channel potential, electric field and drain current for AlGaN/GaN high electron mobility transistor with high-K gate dielectric using two-dimensional Poisson equation under full depletion approximation with the inclusion of effect of polarization charges.

CONSTRAINING THE NFW POTENTIAL WITH OBSERVATIONS AND MODELING OF LOW SURFACE BRIGHTNESS GALAXY VELOCITY FIELDS

International Nuclear Information System (INIS)

Kuzio de Naray, Rachel; McGaugh, Stacy S.; Mihos, J. Christopher

2009-01-01

We model the Navarro-Frenk-White (NFW) potential to determine if, and under what conditions, the NFW halo appears consistent with the observed velocity fields of low surface brightness (LSB) galaxies. We present mock DensePak Integral Field Unit (IFU) velocity fields and rotation curves of axisymmetric and nonaxisymmetric potentials that are well matched to the spatial resolution and velocity range of our sample galaxies. We find that the DensePak IFU can accurately reconstruct the velocity field produced by an axisymmetric NFW potential and that a tilted-ring fitting program can successfully recover the corresponding NFW rotation curve. We also find that nonaxisymmetric potentials with fixed axis ratios change only the normalization of the mock velocity fields and rotation curves and not their shape. The shape of the modeled NFW rotation curves does not reproduce the data: these potentials are unable to simultaneously bring the mock data at both small and large radii into agreement with observations. Indeed, to match the slow rise of LSB galaxy rotation curves, a specific viewing angle of the nonaxisymmetric potential is required. For each of the simulated LSB galaxies, the observer's line of sight must be along the minor axis of the potential, an arrangement that is inconsistent with a random distribution of halo orientations on the sky.

Cannabis co-administration potentiates MDMA effects on temperature and heart rate

NARCIS (Netherlands)

Dumont, G.; Kramers, C.; Sweep, E.; Touw, D.; Van Hasselt, J.; De Kam, M.; Van Gerven, J.; Buitelaar, J.; Verkes, R.J.

2009-01-01

3,4-methylenedioxymethamphetamine (MDMA or “ecstasy”) is a frequently used club-drug in Western societies. Ecstasy users generally are multi-drug users, and cannabis (THC) is commonly combined with MDMA. MDMA is a potent psychostimulant, increasing heart rate, blood pressure and body temperature.

Predicting local field potentials with recurrent neural networks.

Science.gov (United States)

Kim, Louis; Harer, Jacob; Rangamani, Akshay; Moran, James; Parks, Philip D; Widge, Alik; Eskandar, Emad; Dougherty, Darin; Chin, Sang Peter

2016-08-01

We present a Recurrent Neural Network using LSTM (Long Short Term Memory) that is capable of modeling and predicting Local Field Potentials. We train and test the network on real data recorded from epilepsy patients. We construct networks that predict multi-channel LFPs for 1, 10, and 100 milliseconds forward in time. Our results show that prediction using LSTM outperforms regression when predicting 10 and 100 millisecond forward in time.

Everolimus in Heart Transplantation: An Update

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Stephan W. Hirt

2013-01-01

Full Text Available The evidence base relating to the use of everolimus in heart transplantation has expanded considerably in recent years, providing clinically relevant information regarding its use in clinical practice. Unless there are special considerations to take into account, all de novo heart transplant patients can be regarded as potential candidates for immunosuppression with everolimus and reduced-exposure calcineurin inhibitor therapy. Caution about the use of everolimus immediately after transplantation should be exercised in certain patients with the risk of severe proteinuria, with poor wound healing, or with uncontrolled severe hyperlipidemia. Initiation of everolimus in the early phase aftertransplant is not advisable in patients with severe pretransplant end-organ dysfunction or in patients on a left ventricular assist device beforetransplant who are at high risk of infection or of wound healing complications. The most frequent reason for introducing everolimus in maintenance heart transplant patients is to support minimization or withdrawal of calcineurin inhibitor therapy, for example, due to impaired renal function or malignancy. Due to its potential to inhibit the progression of cardiac allograft vasculopathy and to reduce cytomegalovirus infection, everolimus should be initiated as soon as possible after heart transplantation. Immediate and adequate reduction of CNI exposure is mandatory from the start of everolimus therapy.

Motion Planning for Omnidirectional Wheeled Mobile Robot by Potential Field Method

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Weihao Li

2017-01-01

Full Text Available In this paper, potential field method has been used to navigate a three omnidirectional wheels’ mobile robot and to avoid obstacles. The potential field method is used to overcome the local minima problem and the goals nonreachable with obstacles nearby (GNRON problem. For further consideration, model predictive control (MPC has been used to incorporate motion constraints and make the velocity more realistic and flexible. The proposed method is employed based on the kinematic model and dynamics model of the mobile robot in this paper. To show the performance of proposed control scheme, simulation studies have been carried to perform the motion process of mobile robot in specific workplace.

Cardiac telomere length in heart development, function, and disease.

Science.gov (United States)

Booth, S A; Charchar, F J

2017-07-01

Telomeres are repetitive nucleoprotein structures at chromosome ends, and a decrease in the number of these repeats, known as a reduction in telomere length (TL), triggers cellular senescence and apoptosis. Heart disease, the worldwide leading cause of death, often results from the loss of cardiac cells, which could be explained by decreases in TL. Due to the cell-specific regulation of TL, this review focuses on studies that have measured telomeres in heart cells and critically assesses the relationship between cardiac TL and heart function. There are several lines of evidence that have identified rapid changes in cardiac TL during the onset and progression of heart disease as well as at critical stages of development. There are also many factors, such as the loss of telomeric proteins, oxidative stress, and hypoxia, that decrease cardiac TL and heart function. In contrast, antioxidants, calorie restriction, and exercise can prevent both cardiac telomere attrition and the progression of heart disease. TL in the heart is also indicative of proliferative potential and could facilitate the identification of cells suitable for cardiac rejuvenation. Although these findings highlight the involvement of TL in heart function, there are important questions regarding the validity of animal models, as well as several confounding factors, that need to be considered when interpreting results and planning future research. With these in mind, elucidating the telomeric mechanisms involved in heart development and the transition to disease holds promise to prevent cardiac dysfunction and potentiate regeneration after injury. Copyright © 2017 the American Physiological Society.

Comprehensive microRNA profiling reveals potential augmentation of the IL1 pathway in rheumatic heart valve disease.

Science.gov (United States)

Lu, Qiyu; Sun, Yi; Duan, Yuyin; Li, Bin; Xia, Jianming; Yu, Songhua; Zhang, Guimin

2018-03-16

Valvular heart disease is a leading cause of cardiovascular mortality, especially in China. More than a half of valvular heart diseases are caused by acute rheumatic fever. microRNA is involved in many physiological and pathological processes. However, the miRNA profile of the rheumatic valvular heart disease is unknown. This research is to discuss microRNAs and their target gene pathways involved in rheumatic heart valve disease. Serum miRNA from one healthy individual and four rheumatic heart disease patients were sequenced. Specific differentially expressed miRNAs were quantified by Q-PCR in 40 patients, with 20 low-to-moderate rheumatic mitral valve stenosis patients and 20 severe mitral valve stenosis patients. The target relationship between certain miRNA and predicted target genes were analysis by Luciferase reporter assay. The IL-1β and IL1R1 expression levels were analyzed by immunohistochemistry and western blot in the mitral valve from surgery of mitral valve replacement. The results showed that 13 and 91 miRNAs were commonly upregulated or downregulated in all four patients. Nine miRNAs, 1 upregulated and 8 downregulated, that had a similar fold change in all 4 patients were selected for quantitative PCR verification. The results showed similar results from miRNA sequencing. Within these 9 tested miRNAs, hsa-miR-205-3p and hsa-miR-3909 showed a low degree of dispersion between the members of each group. Hsa miR-205-3p and hsa-miR-3909 were predicted to target the 3'UTR of IL-1β and IL1R1 respectively. This was verified by luciferase reporter assays. Immunohistochemistry and Western blot results showed that the mitral valve from rheumatic valve heart disease showed higher levels of IL- 1β and IL1R1 expression compared with congenital heart valve disease. This suggested a difference between rheumatic heart valve disease and other types of heart valve diseases, with more inflammatory responses in the former. In the present study, by next generation

Deregulated Cardiac Specific MicroRNAs in Postnatal Heart Growth

Directory of Open Access Journals (Sweden)

Pujiao Yu

2016-01-01

Full Text Available The heart is recognized as an organ that is terminally differentiated by adulthood. However, during the process of human development, the heart is the first organ with function in the embryo and grows rapidly during the postnatal period. MicroRNAs (miRNAs, miRs, as regulators of gene expression, play important roles during the development of multiple systems. However, the role of miRNAs in postnatal heart growth is still unclear. In this study, by using qRT-PCR, we compared the expression of seven cardiac- or muscle-specific miRNAs that may be related to heart development in heart tissue from mice at postnatal days 0, 3, 8, and 14. Four miRNAs—miR-1a-3p, miR-133b-3p, miR-208b-3p, and miR-206-3p—were significantly decreased while miR-208a-3p was upregulated during the postnatal heart growth period. Based on these results, GeneSpring GX was used to predict potential downstream targets by performing a 3-way comparison of predictions from the miRWalk, PITA, and microRNAorg databases. Gene Ontology (GO and Kyoto Encyclopedia of Genes and Genomes (KEGG analysis were used to identify potential functional annotations and signaling pathways related to postnatal heart growth. This study describes expression changes of cardiac- and muscle-specific miRNAs during postnatal heart growth and may provide new therapeutic targets for cardiovascular diseases.

A physics-based potential and electric field model of a nanoscale ...

Indian Academy of Sciences (India)

In this paper, we have developed a physics-based model for surface potential, channel potential, electric field and drain current for AlGaN/GaN high electron mobility transistor with high-K gate dielectric using two-dimensional Poisson equation under full depletion approximation with the inclusion of effect of polarization ...

Women's Heart Disease: Heart Attack Symptoms

Science.gov (United States)

... of this page please turn JavaScript on. Feature: Women's Heart Disease Heart Attack Symptoms Past Issues / Winter ... most common heart attack symptom in men and women is chest pain or discomfort. However, women also ...

Expression, regulation and putative nutrient-sensing function of taste GPCRs in the heart.

Directory of Open Access Journals (Sweden)

Simon R Foster

Full Text Available G protein-coupled receptors (GPCRs are critical for cardiovascular physiology. Cardiac cells express >100 nonchemosensory GPCRs, indicating that important physiological and potential therapeutic targets remain to be discovered. Moreover, there is a growing appreciation that members of the large, distinct taste and odorant GPCR families have specific functions in tissues beyond the oronasal cavity, including in the brain, gastrointestinal tract and respiratory system. To date, these chemosensory GPCRs have not been systematically studied in the heart. We performed RT-qPCR taste receptor screens in rodent and human heart tissues that revealed discrete subsets of type 2 taste receptors (TAS2/Tas2 as well as Tas1r1 and Tas1r3 (comprising the umami receptor are expressed. These taste GPCRs are present in cultured cardiac myocytes and fibroblasts, and by in situ hybridization can be visualized across the myocardium in isolated cardiac cells. Tas1r1 gene-targeted mice (Tas1r1(Cre/Rosa26(tdRFP strikingly recapitulated these data. In vivo taste receptor expression levels were developmentally regulated in the postnatal period. Intriguingly, several Tas2rs were upregulated in cultured rat myocytes and in mouse heart in vivo following starvation. The discovery of taste GPCRs in the heart opens an exciting new field of cardiac research. We predict that these taste receptors may function as nutrient sensors in the heart.

Insulin resistance and exercise tolerance in heart failure patients

DEFF Research Database (Denmark)

Snoer, Martin; Monk-Hansen, Tea; Olsen, Rasmus Huan

2012-01-01

Insulin resistance has been linked to exercise intolerance in heart failure patients. The aim of this study was to assess the potential role of coronary flow reserve (CFR), endothelial function and arterial stiffness in explaining this linkage.......Insulin resistance has been linked to exercise intolerance in heart failure patients. The aim of this study was to assess the potential role of coronary flow reserve (CFR), endothelial function and arterial stiffness in explaining this linkage....

Actionable Metabolic Pathways in Heart Failure and Cancer—Lessons From Cancer Cell Metabolism

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Anja Karlstaedt

2018-06-01

Full Text Available Recent advances in cancer cell metabolism provide unprecedented opportunities for a new understanding of heart metabolism and may offer new approaches for the treatment of heart failure. Key questions driving the cancer field to understand how tumor cells reprogram metabolism and to benefit tumorigenesis are also applicable to the heart. Recent experimental and conceptual advances in cancer cell metabolism provide the cardiovascular field with the unique opportunity to target metabolism. This review compares cancer cell metabolism and cardiac metabolism with an emphasis on strategies of cellular adaptation, and how to exploit metabolic changes for therapeutic benefit.

The heart tube forms and elongates through dynamic cell rearrangement coordinated with foregut extension.

Science.gov (United States)

Kidokoro, Hinako; Yonei-Tamura, Sayuri; Tamura, Koji; Schoenwolf, Gary C; Saijoh, Yukio

2018-03-29

In the initiation of cardiogenesis, the heart primordia transform from bilateral flat sheets of mesoderm into an elongated midline tube. Here, we discover that this rapid architectural change is driven by actomyosin-based oriented cell rearrangement and resulting dynamic tissue reshaping (convergent extension, CE). By labeling clusters of cells spanning the entire heart primordia, we show that the heart primordia converge toward the midline to form a narrow tube, while extending perpendicularly to rapidly lengthen it. Our data for the first time visualize the process of early heart tube formation from both the medial (second) and lateral (first) heart fields, revealing that both fields form the early heart tube by essentially the same mechanism. Additionally, the adjacent endoderm coordinately forms the foregut through previously unrecognized movements that parallel those of the heart mesoderm and elongates by CE. In conclusion, our data illustrate how initially two-dimensional flat primordia rapidly change their shapes and construct the three-dimensional morphology of emerging organs in coordination with neighboring morphogenesis. © 2018. Published by The Company of Biologists Ltd.

A method to improve the B0 homogeneity of the heart in vivo.

Science.gov (United States)

Jaffer, F A; Wen, H; Balaban, R S; Wolff, S D

1996-09-01

A homogeneous static (B0) magnetic field is required for many NMR experiments such as echo planar imaging, localized spectroscopy, and spiral scan imaging. Although semi-automated techniques have been described to improve the B0 field homogeneity, none has been applied to the in vivo heart. The acquisition of cardiac field maps is complicated by motion, blood flow, and chemical shift artifact from epicardial fat. To overcome these problems, an ungated three-dimensional (3D) chemical shift image (CSI) was collected to generate a time and motion-averaged B0 field map. B0 heterogeneity in the heart was minimized by using a previous algorithm that solves for the optimal shim coil currents for an input field map, using up to third-order current-bounded shims (1). The method improved the B0 homogenelty of the heart in all 11 normal volunteers studied. After application of the algorithm to the unshimmed cardiac field maps, the standard deviation of proton frequency decreased by 43%, the magnitude 1H spectral linewidth decreased by 24%, and the peak-peak gradient decreased by 35%. Simulations of the high-order (second- and third-order) shims in B0 field correction of the heart show that high order shims are important, resulting for nearly half of the improvement in homogeneity for several subjects. The T2* of the left ventricular anterior wall before and after field correction was determined at 4.0 Tesis. Finally, results show that cardiac shimming is of benefit in cardiac 31P NMR spectroscopy and cardiac echo planar imaging.

Potential and flux field landscape theory. I. Global stability and dynamics of spatially dependent non-equilibrium systems.

Science.gov (United States)

Wu, Wei; Wang, Jin

2013-09-28

We established a potential and flux field landscape theory to quantify the global stability and dynamics of general spatially dependent non-equilibrium deterministic and stochastic systems. We extended our potential and flux landscape theory for spatially independent non-equilibrium stochastic systems described by Fokker-Planck equations to spatially dependent stochastic systems governed by general functional Fokker-Planck equations as well as functional Kramers-Moyal equations derived from master equations. Our general theory is applied to reaction-diffusion systems. For equilibrium spatially dependent systems with detailed balance, the potential field landscape alone, defined in terms of the steady state probability distribution functional, determines the global stability and dynamics of the system. The global stability of the system is closely related to the topography of the potential field landscape in terms of the basins of attraction and barrier heights in the field configuration state space. The effective driving force of the system is generated by the functional gradient of the potential field alone. For non-equilibrium spatially dependent systems, the curl probability flux field is indispensable in breaking detailed balance and creating non-equilibrium condition for the system. A complete characterization of the non-equilibrium dynamics of the spatially dependent system requires both the potential field and the curl probability flux field. While the non-equilibrium potential field landscape attracts the system down along the functional gradient similar to an electron moving in an electric field, the non-equilibrium flux field drives the system in a curly way similar to an electron moving in a magnetic field. In the small fluctuation limit, the intrinsic potential field as the small fluctuation limit of the potential field for spatially dependent non-equilibrium systems, which is closely related to the steady state probability distribution functional, is

Apparatus and method for transfer of information by means of a curl-free magnetic vector potential field

International Nuclear Information System (INIS)

Gelinas, R.C.

1984-01-01

A system for transmission of information using a curl-free magnetic vector potential radiation field. The system includes current-carrying apparatus for generating a magnetic vector potential field with a curl-free component coupled to apparatus for modulating the current applied to the field generating apparatus. Receiving apparatus includes a detector with observable properties that vary with the application of an applied curl-free magnetic vector potential field. Analyzing apparatus for determining the information content of modulation imposed on the curl-free vector potential field can be established in materials that are not capable of transmitting more common electromagnetic radiation

Parallel computation of electrostatic potentials and fields in technical geometries on SUPRENUM

International Nuclear Information System (INIS)

Alef, M.

1990-02-01

The programs EPOTZR und EFLDZR have been developed in order to compute electrostatic potentials and the corresponding fields in technical geometries (example: Diode geometry for optimum focussing of ion beams in pulsed high-current ion diodes). The Poisson equation is discretized in a two-dimensional boundary-fitted grid in the (r,z)-plane and solved using multigrid methods. The z- and r-components of the field are determined by numerical differentiation of the potential. This report contains the user's guide of the SUPRENUM versions EPOTZR-P and EFLDZR-P. (orig./HP) [de

Chelation for Coronary Heart Disease

Science.gov (United States)

... more rare are serious and potentially fatal side effects that can include heart failure, a sudden drop in blood pressure, abnormally low calcium levels in the blood (hypocalcemia), permanent kidney damage, and bone marrow depression (blood ...

Cardiovascular magnetic resonance of the charcoal heart

Directory of Open Access Journals (Sweden)

Grill Howard

2008-07-01

Full Text Available Abstract We report a case of malignant melanoma metastasis to the heart presenting as complete heart block. The highlight of the case is to demonstrate that silent cardiac metastasis is not uncommon and CMR has the potential to characterize these cardiac metastases and should be used routinely as a screening tool for those cancers with a high chance of cardiac involvement.

Heart murmurs

Science.gov (United States)

Chest sounds - murmurs; Heart sounds - abnormal; Murmur - innocent; Innocent murmur; Systolic heart murmur; Diastolic heart murmur ... The heart has 4 chambers: Two upper chambers (atria) Two lower chambers (ventricles) The heart has valves that close ...

A Multiagent Potential Field-Based Bot for Real-Time Strategy Games

Directory of Open Access Journals (Sweden)

Johan Hagelbäck

2009-01-01

Full Text Available Bots for real-time strategy (RTS games may be very challenging to implement. A bot controls a number of units that will have to navigate in a partially unknown environment, while at the same time avoid each other, search for enemies, and coordinate attacks to fight them down. Potential fields are a technique originating from the area of robotics where it is used in controlling the navigation of robots in dynamic environments. Although attempts have been made to transfer the technology to the gaming sector, assumed problems with efficiency and high costs for implementation have made the industry reluctant to adopt it. We present a multiagent potential field-based bot architecture that is evaluated in two different real-time strategy game settings and compare them, both in terms of performance, and in terms of softer attributes such as configurability with other state-of-the-art solutions. We show that the solution is a highly configurable bot that can match the performance standards of traditional RTS bots. Furthermore, we show that our approach deals with Fog of War (imperfect information about the opponent units surprisingly well. We also show that a multiagent potential field-based bot is highly competitive in a resource gathering scenario.

Prospective Heart Tracking for Whole-heart Magnetic Resonance Angiography

Science.gov (United States)

Moghari, Mehdi H.; Geva, Tal; Powell, Andrew J.

2015-01-01

Purpose To develop a prospective respiratory-gating technique (Heart-NAV) for use with contrast-enhanced 3D inversion recovery (IR) whole-heart magnetic resonance angiography (MRA) acquisitions that directly tracks heart motion without creating image inflow artifact. Methods With Heart-NAV, 1 of the startup pulses for the whole-heart steady-state free precession MRA sequence is used to collect the centerline of k-space, and its 1-dimensional reconstruction is fed into the standard diaphragm-navigator (NAV) signal analysis process to prospectively gate and track respiratory-induced heart displacement. Ten healthy volunteers underwent non-contrast whole-heart MRA acquisitions using the conventional diaphragm-NAV and Heart-NAV with 5 and 10 mm acceptance windows in a 1.5T scanner. Five patients underwent contrast-enhanced IR whole-heart MRA using a diaphragm-NAV and Heart-NAV with a 5 mm acceptance window. Results For non-contrast whole-heart MRA with both the 5 and 10 mm acceptance windows, Heart-NAV yielded coronary artery vessel sharpness and subjective visual scores that were not significantly different than those using a conventional diaphragm-NAV. Scan time for Heart-NAV was 10% shorter (p<0.05). In patients undergoing contrast-enhanced IR whole-heart MRA, inflow artifact was seen with the diaphragm-NAV but not with Heart-NAV. Conclusion Compared to a conventional diaphragm-NAV, Heart-NAV achieves similar image quality in a slightly shorter scan time and eliminates inflow artifact. PMID:26843458

"The Heart Game": Using Gamification as Part of a Telerehabilitation Program for Heart Patients.

Science.gov (United States)

Dithmer, Marcus; Rasmussen, Jack Ord; Grönvall, Erik; Spindler, Helle; Hansen, John; Nielsen, Gitte; Sørensen, Stine Bæk; Dinesen, Birthe

2016-02-01

The aim of this article is to describe the development and testing of a prototype application ("The Heart Game") using gamification principles to assist heart patients in their telerehabilitation process in the Teledialog project. A prototype game was developed via user-driven innovation and tested on 10 patients 48-89 years of age and their relatives for a period of 2 weeks. The application consisted of a series of daily challenges given to the patients and relatives and was based on several gamification principles. A triangulation of data collection techniques (interviews, participant observations, focus group interviews, and workshop) was used. Interviews with three healthcare professionals and 10 patients were carried out over a period of 2 weeks in order to evaluate the use of the prototype. The heart patients reported the application to be a useful tool as a part of their telerehabilitation process in everyday life. Gamification and gameful design principles such as leaderboards, relationships, and achievements engaged the patients and relatives. The inclusion of a close relative in the game motivated the patients to perform rehabilitation activities. "The Heart Game" concept presents a new way to motivate heart patients by using technology as a social and active approach to telerehabilitation. The findings show the potential of using gamification for heart patients as part of a telerehabilitation program. The evaluation indicated that the inclusion of the patient's spouse in the rehabilitation activities could be an effective strategy. A major challenge in using gamification for heart patients is avoiding a sense of defeat while still adjusting the level of difficulty to the individual patient.

The potential application of stem cell in dentistry

Directory of Open Access Journals (Sweden)

Ketut Suardita

2006-12-01

Full Text Available Stem cells are generally defined as cells that have the capacity to self-renewal and differentiate to specialize cell. There are two kinds of stem cell, embryonic stem cell and adult stem cells. Stem cell therapy has been used to treat diseases including Parkinson’s and Alzheimer’s diseases, spinal cord injury, stroke, burns, heart diseases, diabetes, osteoarthritis, and rheumatoid arthritis. Stem cells were found in dental pulp, periodontal ligament, and alveolar bone marrow. Because of their potential in medical therapy, stem cells were used to regenerate lost or damage teeth and periodontal structures. This article discusses the potential application of stem cells for dental field.

Cancer Therapy Targeting the HER2-PI3K Pathway: Potential Impact on the Heart

Directory of Open Access Journals (Sweden)

Giannoula Lakka Klement

2012-06-01

Full Text Available The HER2-PI3K pathway is the one of the most mutated pathways in cancer. Several drugs targeting the major kinases of this pathway have been approved by the Food and Drug Administration and many are being tested in clinical trials for the treatment of various cancers. However, the HER2-PI3K pathway is also pivotal for maintaining the physiological function of the heart, especially in the presence of cardiac stress. Clinical studies have shown that in patients treated with doxorubicin concurrently with Trastuzumab, a monoclonal antibody that blocks the HER2 receptor, the New York Heart Association class III/IV heart failure was significantly increased compared to those who were treated with doxorubicin alone (16 vs. 3%. Studies in transgenic mice have also shown that other key kinases of this pathway, such as PI3Kα, PDK1, Akt and mTOR, are important for protecting the heart from ischemia-reperfusion and aortic stenosis induced cardiac dysfunction. Studies, however, have also shown that inhibition of PI3Kγ improve cardiac function of a failing heart. In addition, results from transgenic mouse models are not always consistent with the outcome of the pharmacological inhibition of this pathway. Here, we will review these findings and discuss how we can address the cardiac side-effects caused by inhibition of this important pathway in both cancer and cardiac biology.

Radiation-induced damage of the Wistar Rat heart

International Nuclear Information System (INIS)

Cilliers, G.D.; Lochner, A.

1993-01-01

A time sequence study was performed on Wistar rats to investigate the early effects of radiation on the mechanical function and energy metabolism of the heart. Two series of rats were exposed to 20 Gy electron irradiation to a field including the heart and approximately a third of the lungs. The hearts were excised at varying time intervals (8-180 days) post irradiation. In one series of hearts the mechanical function was measured using the isolated perfused working rat heart model. At the end of the perfusion the hearts were freeze-clamped for analysis of the high energy phosphate contents (ATP, ADP, AMP and creatine phosphate). In the second series, mitochondria were isolated and the oxidative phosphorylation function measured polarographically (substrate: glutamate). Maximal depression of mechanical function was observed at 60 days post irradiation. Thereafter the work performance of these hearts improved significantly, almost reaching control levels after 180 days. The mitochondrial oxidative phosphorylation function (as measured on the total mitochondrial population) was significantly depressed 30-120 days post irradiation. As in the case of the mechanical changes, the depression was transient and after 180 days post irradiation, values similar to those of controls were obtained. Myocardial high energy phosphates remained unaltered throughout the experiment. (author)

Microarray Expression Profile of Circular RNAs in Heart Tissue of Mice with Myocardial Infarction-Induced Heart Failure

Directory of Open Access Journals (Sweden)

Hong-Jin Wu

2016-06-01

Full Text Available Background/Aims: Myocardial infarction (MI is a serious complication of atherosclerosis associated with increasing mortality attributable to heart failure. This study is aimed to assess the global changes in and characteristics of the transcriptome of circular RNAs (circRNAs in heart tissue during MI induced heart failure (HF. Methods: Using a post-myocardial infarction (MI model of HF in mice, we applied microarray assay to examine the transcriptome of circRNAs deregulated in the heart during HF. We confirmed the changes in circRNAs by quantitative PCR. Results: We revealed and confirmed a number of circRNAs that were deregulated during HF, which suggests a potential role of circRNAs in HF. Conclusions: The distinct expression patterns of circulatory circRNAs during HF indicate that circRNAs may actively respond to stress and thus serve as biomarkers of HF diagnosis and treatment.

The CopenHeartSF trial—comprehensive sexual rehabilitation programme for male patients with implantable cardioverter defibrillator or ischaemic heart disease and impaired sexual function

DEFF Research Database (Denmark)

Johansen, Pernille Palm; Zwisler, Ann-Dorthe; Svendsen, Jesper Hastrup

2013-01-01

Sexuality is an important part of people's physical and mental health. Patients with heart disease often suffer from sexual dysfunction. Sexual dysfunction has a negative impact on quality of life and well-being in persons with heart disease, and sexual dysfunction is associated with anxiety...... and depression. Treatment and care possibilities seem to be lacking. Studies indicate that non-pharmacological interventions such as exercise training and psychoeducation possess the potential of reducing sexual dysfunction in patients with heart disease. The CopenHeartSF trial will investigate the effect...

FUNCTIONALLY UNIVENTRICULAR HEARTS: IMPACT OF PRE-NATAL DIAGNOSIS

Directory of Open Access Journals (Sweden)

Antonio Francesco Corno

2015-02-01

Full Text Available Within the last few decades the pre-natal echocardiographic diagnosis of congenital heart defects has made substantial progresses, particularly for the identification of complex malformation. Functionally univentricular hearts categorize a huge variety of heart malformations. Since no one of the patients with these congenital heart defects can ever undergo a bi-ventricular type of repair, early recognition and decision-making from the neonatal period are required in order to allow for appropriate multiple-step diagnostic and treatment procedures, either of interventional cardiology and/or surgery, on the pathway of univentricular heart. In the literature strong disagreements exist about the potential impact of the pre-natal diagnosis on the early and late outcomes of complex congenital heart defects. This review of the recent reports has been undertaken to better understand the impact of pre-natal diagnosis in functionally univentricular hearts taking into consideration the following topics:•pre-natal screening•outcomes and survival•general morbidity•neurologic and developmental consequences•pregnancy management and delivery planning•resources utilization and costs/benefits issues•ethical implications, parents counseling, interruption of pregnancy versus treatment

Exposure of the Heart in Breast Cancer Radiation Therapy: A Systematic Review of Heart Doses Published During 2003 to 2013

International Nuclear Information System (INIS)

Taylor, Carolyn W.; Wang, Zhe; Macaulay, Elizabeth; Jagsi, Reshma; Duane, Frances; Darby, Sarah C.

2015-01-01

Purpose: Breast cancer radiation therapy cures many women, but where the heart is exposed, it can cause heart disease. We report a systematic review of heart doses from breast cancer radiation therapy that were published during 2003 to 2013. Methods and Materials: Eligible studies were those reporting whole-heart dose (ie, dose averaged over the whole heart). Analyses considered the arithmetic mean of the whole-heart doses for the CT plans for each regimen in each study. We termed this “mean heart dose.” Results: In left-sided breast cancer, mean heart dose averaged over all 398 regimens reported in 149 studies from 28 countries was 5.4 Gy (range, <0.1-28.6 Gy). In regimens that did not include the internal mammary chain (IMC), average mean heart dose was 4.2 Gy and varied with the target tissues irradiated. The lowest average mean heart doses were from tangential radiation therapy with either breathing control (1.3 Gy; range, 0.4-2.5 Gy) or treatment in the lateral decubitus position (1.2 Gy; range, 0.8-1.7 Gy), or from proton radiation therapy (0.5 Gy; range, 0.1-0.8 Gy). For intensity modulated radiation therapy mean heart dose was 5.6 Gy (range, <0.1-23.0 Gy). Where the IMC was irradiated, average mean heart dose was around 8 Gy and varied little according to which other targets were irradiated. Proton radiation therapy delivered the lowest average mean heart dose (2.6 Gy, range, 1.0-6.0 Gy), and tangential radiation therapy with a separate IMC field the highest (9.2 Gy, range, 1.9-21.0 Gy). In right-sided breast cancer, the average mean heart dose was 3.3 Gy based on 45 regimens in 23 studies. Conclusions: Recent estimates of typical heart doses from left breast cancer radiation therapy vary widely between studies, even for apparently similar regimens. Maneuvers to reduce heart dose in left tangential radiation therapy were successful. Proton radiation therapy delivered the lowest doses. Inclusion of the IMC doubled typical heart dose.

Pharmacogenetics: progress, pitfalls and clinical potential for coronary heart disease.

Science.gov (United States)

Humphries, Steve E; Hingorani, Aroon

2006-02-01

Much has been written about the potential of pharmacogenetic testing to inform therapy based on an individual's genetic makeup, and to decide the most effective choice of available drugs, or to avoid dangerous side effects. Currently, there is little hard data for either in the field of cardiovascular disease. The usual approach has been opportunistic use of drug trials in unrelated patients, and to look for differences in response or outcome by "candidate gene" genotype, for example genes coding for drug metabolising enzymes (activators and metabolisers), and enzymes and receptors involved in lipid metabolism, adrenergic response, etc. As with all association studies, initially promising results have often failed the test of replication in larger studies, and the relationship between the CETP Taq-I variant and response to statins has now been disproved. The strongest data to date is the report [Chasman, D.I., Posada, D., Subrahmanyan, L., Cook, N.R., Stanton Jr., V.P., Ridker, P.M., 2004. Pharmacogenetic study of statin therapy and cholesterol reduction. J. Am. Med. Assoc. 291, 2821-2827] of a poorer cholesterol-lowering response to Pravastatin in the 7% of patients carrying a certain haplotype of the HMG CoA reductase gene (14% fall versus 19%), but if this is overcome simply by a higher dose, it is of little clinical relevance. Currently, the best example of avoiding side effects is determining genotype at the CYP2C9 locus with respect of warfarin treatment, since carriers for functional variants (>20% of the population) require lower doses for optimal anticoagulation, and homozygotes, although rare, may well experience serious bleeding if given a usual dose. The full potential of this field will only be realised with much further work.

Exploring uncertainty in the Earth Sciences - the potential field perspective

Science.gov (United States)

Saltus, R. W.; Blakely, R. J.

2013-12-01

Interpretation of gravity and magnetic anomalies is mathematically non-unique because multiple theoretical solutions are possible. The mathematical label of 'non-uniqueness' can lead to the erroneous impression that no single interpretation is better in a geologic sense than any other. The purpose of this talk is to present a practical perspective on the theoretical non-uniqueness of potential field interpretation in geology. There are multiple ways to approach and constrain potential field studies to produce significant, robust, and definitive results. For example, a smooth, bell-shaped gravity profile, in theory, could be caused by an infinite set of physical density bodies, ranging from a deep, compact, circular source to a shallow, smoothly varying, inverted bell-shaped source. In practice, however, we can use independent geologic or geophysical information to limit the range of possible source densities and rule out many of the theoretical solutions. We can further reduce the theoretical uncertainty by careful attention to subtle anomaly details. For example, short-wavelength anomalies are a well-known and theoretically established characteristic of shallow geologic sources. The 'non-uniqueness' of potential field studies is closely related to the more general topic of scientific uncertainty in the Earth sciences and beyond. Nearly all results in the Earth sciences are subject to significant uncertainty because problems are generally addressed with incomplete and imprecise data. The increasing need to combine results from multiple disciplines into integrated solutions in order to address complex global issues requires special attention to the appreciation and communication of uncertainty in geologic interpretation.

Effects of an electric field on the confined hydrogen atom in a parabolic potential well

International Nuclear Information System (INIS)

Xie Wenfang

2009-01-01

Using the perturbation method, the confined hydrogen atom by a parabolic potential well is investigated. The binding energy of the confined hydrogen atom in a parabolic potential well is calculated as a function of the confined potential radius and as a function of the intensity of an applied electric field. It is shown that the binding energy of the confined hydrogen atom is highly dependent on the confined potential radius and the intensity of an applied electric field.

Heart Failure

Science.gov (United States)

Heart failure is a condition in which the heart can't pump enough blood to meet the body's needs. Heart failure does not mean that your heart has stopped ... and shortness of breath Common causes of heart failure are coronary artery disease, high blood pressure and ...

Respiratory gating and multi field technique radiotherapy for esophageal cancer

International Nuclear Information System (INIS)

Ohta, Atsushi; Kaidu, Motoki; Tanabe, Satoshi

2017-01-01

To investigate the effects of a respiratory gating and multi field technique on the dose-volume histogram (DVH) in radiotherapy for esophageal cancer. Twenty patients who underwent four-dimensional computed tomography for esophageal cancer were included. We retrospectively created the four treatment plans for each patient, with or without the respiratory gating and multi field technique: No gating-2-field, No gating-4-field, Gating-2-field, and Gating-4-field plans. We compared the DVH parameters of the lung and heart in the No gating-2-field plan with the other three plans.Result In the comparison of the parameters in the No gating-2-field plan, there are significant differences in the Lung V 5Gy , V 20Gy , mean dose with all three plans and the Heart V 25Gy -V 40Gy with Gating-2-field plan, V 35Gy , V 40Gy , mean dose with No Gating-4-field plan and V 30Gy -V 40Gy , and mean dose with Gating-4-field plan. The lung parameters were smaller in the Gating-2-field plan and larger in the No gating-4-field and Gating-4-field plans. The heart parameters were all larger in the No gating-2-field plan. The lung parameters were reduced by the respiratory gating technique and increased by the multi field technique. The heart parameters were reduced by both techniques. It is important to select the optimal technique according to the risk of complications. (author)

Cardiovascular fluid dynamics. Methods for flow and pressure field analysis from magnetic resonance imaging

International Nuclear Information System (INIS)

Ebbers, T.

2001-01-01

Cardiovascular blood flow is highly complex and incompletely understood. Blood flow patterns are expected to influence the opening and closing of normal and prosthetic heart valves, the efficiency of cardiac filling and ejection, and the resistance to thrombus formation within the heart. Conventional diagnostic techniques are poorly suited to the study of the three-dimensional (3D) blood flow patterns in the heart chambers and large vessels. Noninvasive methods have also been inadequate in studying intracardiac pressure differences, which are the driving force of flow and are critical in the evaluation of many cardiovascular abnormalities. This thesis focuses on the development of non-invasive methods for analysis of 3D cardiovascular blood flow. Simultaneous study of cardiovascular fluid dynamics allowed knowledge exchange across the two disciplines, facilitating the development process and broadening the applicability of the methods. A time-resolved 3D phase-contrast Magnetic Resonance Imaging (MRI) technique was used to acquire the velocity vector field in a 3D volume encompassing the entire heart or a large vessel. Cardiovascular blood flow patterns were visualized by use of particle traces, which revealed, for instance, vortical flow patterns in the left atrium. By applying the Navier-Stokes equation along a user-defined line in the 3D velocity vector field, the relative pressure could be obtained as an excellent supplement to the flow pattern visualization. Using a delineation of the blood pool, the time-varying 3D relative pressure field in the human left ventricle was obtained from the velocity field by use of the pressure Poisson equation. A delineation of the heart muscle, a task that is almost impossible to perform on 3D MRI either automatically or manually, was also achieved by usage of particle traces. This segmentation allows automatic calculation of the 3D relative pressure field, as well as calculation of well-established parameters such as

Cardiovascular fluid dynamics. Methods for flow and pressure field analysis from magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Ebbers, T

2001-05-01

Cardiovascular blood flow is highly complex and incompletely understood. Blood flow patterns are expected to influence the opening and closing of normal and prosthetic heart valves, the efficiency of cardiac filling and ejection, and the resistance to thrombus formation within the heart. Conventional diagnostic techniques are poorly suited to the study of the three-dimensional (3D) blood flow patterns in the heart chambers and large vessels. Noninvasive methods have also been inadequate in studying intracardiac pressure differences, which are the driving force of flow and are critical in the evaluation of many cardiovascular abnormalities. This thesis focuses on the development of non-invasive methods for analysis of 3D cardiovascular blood flow. Simultaneous study of cardiovascular fluid dynamics allowed knowledge exchange across the two disciplines, facilitating the development process and broadening the applicability of the methods. A time-resolved 3D phase-contrast Magnetic Resonance Imaging (MRI) technique was used to acquire the velocity vector field in a 3D volume encompassing the entire heart or a large vessel. Cardiovascular blood flow patterns were visualized by use of particle traces, which revealed, for instance, vortical flow patterns in the left atrium. By applying the Navier-Stokes equation along a user-defined line in the 3D velocity vector field, the relative pressure could be obtained as an excellent supplement to the flow pattern visualization. Using a delineation of the blood pool, the time-varying 3D relative pressure field in the human left ventricle was obtained from the velocity field by use of the pressure Poisson equation. A delineation of the heart muscle, a task that is almost impossible to perform on 3D MRI either automatically or manually, was also achieved by usage of particle traces. This segmentation allows automatic calculation of the 3D relative pressure field, as well as calculation of well-established parameters such as

Heart MRI

Science.gov (United States)

Magnetic resonance imaging - cardiac; Magnetic resonance imaging - heart; Nuclear magnetic resonance - cardiac; NMR - cardiac; MRI of the heart; Cardiomyopathy - MRI; Heart failure - MRI; Congenital heart disease - MRI

Brain derived neurotrophic factor contributes to the cardiogenic potential of adult resident progenitor cells in failing murine heart.

Directory of Open Access Journals (Sweden)

Rasmita Samal

Full Text Available Resident cardiac progenitor cells show homing properties when injected into the injured but not to the healthy myocardium. The molecular background behind this difference in behavior needs to be studied to elucidate how adult progenitor cells can restore cardiac function of the damaged myocardium. Since the brain derived neurotrophic factor (BDNF moderates cardioprotection in injured hearts, we focused on delineating its regulatory role in the damaged myocardium.Comparative gene expression profiling of freshly isolated undifferentiated Sca-1 progenitor cells derived either from heart failure transgenic αMHC-CyclinT1/Gαq overexpressing mice or wildtype littermates revealed transcriptional variations. Bdnf expression was up regulated 5-fold during heart failure which was verified by qRT-PCR and confirmed at protein level. The migratory capacity of Sca-1 cells from transgenic hearts was improved by 15% in the presence of 25 ng/ml BDNF. Furthermore, BDNF-mediated effects on Sca-1 cells were studied via pulsed Stable Isotope Labeling of Amino acids in Cell Culture (pSILAC proteomics approach. After BDNF treatment significant differences between newly synthesized proteins in Sca-1 cells from control and transgenic hearts were observed for CDK1, SRRT, HDGF, and MAP2K3 which are known to regulate cell cycle, survival and differentiation. Moreover BDNF repressed the proliferation of Sca-1 cells from transgenic hearts.Comparative profiling of resident Sca-1 cells revealed elevated BDNF levels in the failing heart. Exogenous BDNF (i stimulated migration, which might improve the homing ability of Sca-1 cells derived from the failing heart and (ii repressed the cell cycle progression suggesting its potency to ameliorate heart failure.

New Trends in Heart Regeneration: A Review

Directory of Open Access Journals (Sweden)

Kochegarov A

2016-11-01

Full Text Available In this review, we focus on new approaches that could lead to the regeneration of heart muscle and the restoration of cardiac muscle function derived from newly-formed cardiomyocytes. Various strategies for the production of cardiomyocytes from embryonic stem cells, induced pluripotent stem cells, adult bone marrow stem cells and cardiac spheres from human heart biopsies are described. Pathological conditions which lead to atherosclerosis and coronary artery disease often are followed by myocardial infarction causing myocardial cell death. After cell death, there is very little self-regeneration of the cardiac muscle tissue, which is replaced by non-contractile connective tissue, thus weakening the ability of the heart muscle to contract fully and leading to heart failure. A number of experimental research approaches to stimulate heart muscle regeneration with the hope of regaining normal or near normal heart function in the damaged heart muscle have been attempted. Some of these very interesting studies have used a variety of stem cell types in combination with potential cardiogenic differentiation factors in an attempt to promote differentiation of new cardiac muscle for possible future use in the clinical treatment of patients who have suffered heart muscle damage from acute myocardial infarctions or related cardiovascular diseases. Although progress has been made in recent years relative to promoting the differentiation of cardiac muscle tissue from non-muscle cells, much work remains to be done for this technology to be used routinely in translational clinical medicine to treat patients with damaged heart muscle tissue and return such individuals to pre-heart-attack activity levels.

'A Change of Heart': Racial Politics, Scientific Metaphor and Coverage of 1968 Interracial Heart Transplants in the African American Press.

Science.gov (United States)

Koretzky, Maya Overby

2017-05-01

This paper explores the African American response to an interracial heart transplant in 1968 through a close reading of the black newspaper press. This methodological approach provides a window into African American perceptions of physiological difference between the races, or lack thereof, as it pertained to both personal identity and race politics. Coverage of the first interracial heart transplant, which occurred in apartheid South Africa, was multifaceted. Newspapers lauded the transplant as evidence of physiological race equality while simultaneously mobilising the language of differing 'black' and 'white' hearts to critique racist politics through the metaphor of a 'change of heart'. While interracial transplant created the opportunity for such political commentary, its material reality-potential exploitation of black bodies for white gain-was increasingly a cause for concern, especially after a contentious heart transplant from a black to a white man in May 1968 in the American South.

Inversion of potential-field data for layers with uneven thickness

OpenAIRE

Caratori Tontini, F.; Cocchi, L.; Carmisciano, C.; Stefanelli, P.

2008-01-01

AB: Inversion of large-scale potential-field anomalies, aimed at determining density or magnetization, is usually made in the Fourier domain. The commonly adopted geometry is based on a layer of constant thickness, characterized by a bottom surface at a fixed distance from the top surface.....

Brain-Heart Interaction: Cardiac Complications After Stroke.

Science.gov (United States)

Chen, Zhili; Venkat, Poornima; Seyfried, Don; Chopp, Michael; Yan, Tao; Chen, Jieli

2017-08-04

Neurocardiology is an emerging specialty that addresses the interaction between the brain and the heart, that is, the effects of cardiac injury on the brain and the effects of brain injury on the heart. This review article focuses on cardiac dysfunction in the setting of stroke such as ischemic stroke, brain hemorrhage, and subarachnoid hemorrhage. The majority of post-stroke deaths are attributed to neurological damage, and cardiovascular complications are the second leading cause of post-stroke mortality. Accumulating clinical and experimental evidence suggests a causal relationship between brain damage and heart dysfunction. Thus, it is important to determine whether cardiac dysfunction is triggered by stroke, is an unrelated complication, or is the underlying cause of stroke. Stroke-induced cardiac damage may lead to fatality or potentially lifelong cardiac problems (such as heart failure), or to mild and recoverable damage such as neurogenic stress cardiomyopathy and Takotsubo cardiomyopathy. The role of location and lateralization of brain lesions after stroke in brain-heart interaction; clinical biomarkers and manifestations of cardiac complications; and underlying mechanisms of brain-heart interaction after stroke, such as the hypothalamic-pituitary-adrenal axis; catecholamine surge; sympathetic and parasympathetic regulation; microvesicles; microRNAs; gut microbiome, immunoresponse, and systemic inflammation, are discussed. © 2017 American Heart Association, Inc.

Heart Health - Heart Disease: Symptoms, Diagnosis, Treatment

Science.gov (United States)

... Bar Home Current Issue Past Issues Cover Story Heart Health Heart Disease: Symptoms, Diagnosis, Treatment Past Issues / Winter 2009 ... of this page please turn Javascript on. Most heart attacks happen when a clot in the coronary ...

Heart rate measurement based on face video sequence

Science.gov (United States)

Xu, Fang; Zhou, Qin-Wu; Wu, Peng; Chen, Xing; Yang, Xiaofeng; Yan, Hong-jian

2015-03-01

This paper proposes a new non-contact heart rate measurement method based on photoplethysmography (PPG) theory. With this method we can measure heart rate remotely with a camera and ambient light. We collected video sequences of subjects, and detected remote PPG signals through video sequences. Remote PPG signals were analyzed with two methods, Blind Source Separation Technology (BSST) and Cross Spectral Power Technology (CSPT). BSST is a commonly used method, and CSPT is used for the first time in the study of remote PPG signals in this paper. Both of the methods can acquire heart rate, but compared with BSST, CSPT has clearer physical meaning, and the computational complexity of CSPT is lower than that of BSST. Our work shows that heart rates detected by CSPT method have good consistency with the heart rates measured by a finger clip oximeter. With good accuracy and low computational complexity, the CSPT method has a good prospect for the application in the field of home medical devices and mobile health devices.

Local Field Potentials: Myths and Misunderstandings

Directory of Open Access Journals (Sweden)

Oscar Herreras

2016-12-01

Full Text Available The intracerebral local field potential (LFP is a measure of brain activity that reflects the highly dynamic flow of information across neural networks. This is a composite signal that receives contributions from multiple neural sources, yet interpreting its nature and significance may be hindered by several confounding factors and technical limitations. By and large, the main factor defining the amplitude of LFPs is the geometry of the current sources, over and above the degree of synchronization or the properties of the media. As such, similar levels of activity may result in potentials that differ in several orders of magnitude in different populations. The geometry of these sources has been experimentally inaccessible until intracerebral high density recordings enabled the co-activating sources to be revealed. Without this information, it has proven difficult to interpret a century’s worth of recordings that used temporal cues alone, such as event or spike related potentials and frequency bands. As such, a collection of biophysically ill-founded concepts have been considered legitimate, which can now be corrected in the light of recent advances. The relationship of LFPs to their sources is often counterintuitive. For instance, most LFP activity is not local but remote, it may be larger further from rather than close to the source, the polarity does not define its excitatory or inhibitory nature, and the amplitude may increase when source’s activity is reduced. As technological developments foster the use of LFPs, the time is now ripe to raise awareness of the need to take into account spatial aspects of these signals and of the errors derived from neglecting to do so.

Heart Health: The Heart Truth Campaign 2009

Science.gov (United States)

... Bar Home Current Issue Past Issues Cover Story Heart Health The Heart Truth Campaign 2009 Past Issues / Winter 2009 Table ... one of the celebrities supporting this year's The Heart Truth campaign. Both R&B singer Ashanti (center) ...

Women's Heart Disease: Heart Disease Risk Factors

Science.gov (United States)

... this page please turn JavaScript on. Feature: Women's Heart Disease Heart Disease Risk Factors Past Issues / Winter 2014 Table ... or habits may raise your risk for coronary heart disease (CHD). These conditions are known as risk ...

Worsening renal function in heart failure: the need for a consensus definition.

Science.gov (United States)

Sheerin, Noella J; Newton, Phillip J; Macdonald, Peter S; Leung, Dominic Y C; Sibbritt, David; Spicer, Stephen Timothy; Johnson, Kay; Krum, Henry; Davidson, Patricia M

2014-07-01

Acute decompensated heart failure is a common cause of hospitalisation. This is a period of vulnerability both in altered pathophysiology and also the potential for iatrogenesis due to therapeutic interventions. Renal dysfunction is often associated with heart failure and portends adverse outcomes. Identifying heart failure patients at risk of renal dysfunction is important in preventing progression to chronic kidney disease or worsening renal function, informing adjustment to medication management and potentially preventing adverse events. However, there is no working or consensus definition in international heart failure management guidelines for worsening renal function. In addition, there appears to be no concordance or adaptation of chronic kidney disease guidelines by heart failure guideline development groups for the monitoring of chronic kidney disease in heart failure. Our aim is to encourage the debate for an agreed definition given the prognostic impact of worsening renal function in heart failure. We present the case for the uptake of the Acute Kidney Injury Network criteria for acute kidney injury with some minor alterations. This has the potential to inform study design and meta-analysis thereby building the knowledgebase for guideline development. Definition consensus supports data element, clinical registry and electronic algorithm innovation as instruments for quality improvement and clinical research for better patient outcomes. In addition, we recommend all community managed heart failure patients have their baseline renal function classified and routinely monitored in accordance with established renal guidelines to help identify those at increased risk for worsening renal function or progression to chronic kidney disease. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

“The Heart Game”: Using Gamification as Part of a Telerehabilitation Program for Heart Patients

Science.gov (United States)

Dithmer, Marcus; Grönvall, Erik; Spindler, Helle; Hansen, John; Nielsen, Gitte; Sørensen, Stine Bæk; Dinesen, Birthe

2016-01-01

Abstract Objective: The aim of this article is to describe the development and testing of a prototype application (“The Heart Game”) using gamification principles to assist heart patients in their telerehabilitation process in the Teledialog project. Materials and Methods: A prototype game was developed via user-driven innovation and tested on 10 patients 48–89 years of age and their relatives for a period of 2 weeks. The application consisted of a series of daily challenges given to the patients and relatives and was based on several gamification principles. A triangulation of data collection techniques (interviews, participant observations, focus group interviews, and workshop) was used. Interviews with three healthcare professionals and 10 patients were carried out over a period of 2 weeks in order to evaluate the use of the prototype. Results: The heart patients reported the application to be a useful tool as a part of their telerehabilitation process in everyday life. Gamification and gameful design principles such as leaderboards, relationships, and achievements engaged the patients and relatives. The inclusion of a close relative in the game motivated the patients to perform rehabilitation activities. Conclusions: “The Heart Game” concept presents a new way to motivate heart patients by using technology as a social and active approach to telerehabilitation. The findings show the potential of using gamification for heart patients as part of a telerehabilitation program. The evaluation indicated that the inclusion of the patient's spouse in the rehabilitation activities could be an effective strategy. A major challenge in using gamification for heart patients is avoiding a sense of defeat while still adjusting the level of difficulty to the individual patient. PMID:26579590

ASD Closure in Structural Heart Disease.

Science.gov (United States)

Wiktor, Dominik M; Carroll, John D

2018-04-17

While the safety and efficacy of percutaneous ASD closure has been established, new data have recently emerged regarding the negative impact of residual iatrogenic ASD (iASD) following left heart structural interventions. Additionally, new devices with potential advantages have recently been studied. We will review here the potential indications for closure of iASD along with new generation closure devices and potential late complications requiring long-term follow-up. With the expansion of left-heart structural interventions and large-bore transseptal access, there has been growing experience gained with management of residual iASD. Some recently published reports have implicated residual iASD after these procedures as a potential source of diminished clinical outcomes and mortality. Additionally, recent trials investigating new generation closure devices as well as expanding knowledge regarding late complications of percutaneous ASD closure have been published. While percutaneous ASD closure is no longer a novel approach to managing septal defects, there are several contemporary issues related to residual iASD following large-bore transseptal access and new generation devices which serve as an impetus for this review. Ongoing attention to potential late complications and decreasing their incidence with ongoing study is clearly needed.

The auxiliary field method and approximate analytical solutions of the Schroedinger equation with exponential potentials

Energy Technology Data Exchange (ETDEWEB)

Silvestre-Brac, Bernard [LPSC Universite Joseph Fourier, Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, Avenue des Martyrs 53, F-38026 Grenoble-Cedex (France); Semay, Claude; Buisseret, Fabien [Groupe de Physique Nucleaire Theorique, Universite de Mons-Hainaut, Academie universitaire Wallonie-Bruxelles, Place du Parc 20, B-7000 Mons (Belgium)], E-mail: silvestre@lpsc.in2p3.fr, E-mail: claude.semay@umh.ac.be, E-mail: fabien.buisseret@umh.ac.be

2009-06-19

The auxiliary field method is a new and efficient way to compute approximate analytical eigenenergies of the Schroedinger equation. This method has already been successfully applied to the case of central potentials of power-law and logarithmic forms. In the present work, we show that the Schroedinger equation with exponential potentials of the form -{alpha}r{sup {lambda}}exp(-{beta}r) can also be analytically solved by using the auxiliary field method. Closed formulae giving the critical heights and the energy levels of these potentials are presented. Special attention is drawn to the Yukawa potential and the pure exponential potential.

The auxiliary field method and approximate analytical solutions of the Schroedinger equation with exponential potentials

International Nuclear Information System (INIS)

Silvestre-Brac, Bernard; Semay, Claude; Buisseret, Fabien

2009-01-01

The auxiliary field method is a new and efficient way to compute approximate analytical eigenenergies of the Schroedinger equation. This method has already been successfully applied to the case of central potentials of power-law and logarithmic forms. In the present work, we show that the Schroedinger equation with exponential potentials of the form -αr λ exp(-βr) can also be analytically solved by using the auxiliary field method. Closed formulae giving the critical heights and the energy levels of these potentials are presented. Special attention is drawn to the Yukawa potential and the pure exponential potential

An analytical expression of electric potential and field of organic thin film transistors

International Nuclear Information System (INIS)

Pankalla, S; Glesner, M

2012-01-01

The two-dimensional electric potential and field of an organic thin-film transistor (OTFT) is derived by conformal mapping using the Schwarz-Christoffel-transformation of the Poisson equation. In this paper we compare this analytical closed-form solution to field simulation results from Silvaco TCAD. Inter alia the potential close to the surface is calculated and we found excellent accordance to the numerical simulations and thus proofed its usability for charge transport calculations. Thus, it is used for calculation of the drain-source-current in the channel.

Association of plasma uric acid with ischaemic heart disease and blood pressure

DEFF Research Database (Denmark)

Palmer, Tom M; Nordestgaard, Børge G; Benn, Marianne

2013-01-01

To assess the associations between both uric acid levels and hyperuricaemia, with ischaemic heart disease and blood pressure, and to explore the potentially confounding role of body mass index.......To assess the associations between both uric acid levels and hyperuricaemia, with ischaemic heart disease and blood pressure, and to explore the potentially confounding role of body mass index....

NS5806 partially restores action potential duration but fails to ameliorate calcium transient dysfunction in a computational model of canine heart failure

DEFF Research Database (Denmark)

Maleckar, Mary M; Lines, Glenn T; Koivumäki, Jussi T

2014-01-01

AIMS: The study investigates how increased Ito, as mediated by the activator NS5806, affects excitation-contraction coupling in chronic heart failure (HF). We hypothesized that restoring spike-and-dome morphology of the action potential (AP) to a healthy phenotype would be insufficient to restore...... the intracellular Ca(2) (+) transient (CaT), due to HF-induced remodelling of Ca(2+) handling. METHODS AND RESULTS: An existing mathematical model of the canine ventricular myocyte was modified to incorporate recent experimental data from healthy and failing myocytes, resulting in models of both healthy and HF...... ionic processes with a focus on calcium transients (CaT), how these were altered in HF across the ventricular wall, and the subsequent effects of varying compound concentration in HF. Heart failure model variants recapitulated a characteristic increase in AP duration (APD) in the disease...

Myocardial Polyploidization Creates a Barrier to Heart Regeneration in Zebrafish.

Science.gov (United States)

González-Rosa, Juan Manuel; Sharpe, Michka; Field, Dorothy; Soonpaa, Mark H; Field, Loren J; Burns, Caroline E; Burns, C Geoffrey

2018-02-26

Correlative evidence suggests that polyploidization of heart muscle, which occurs naturally in post-natal mammals, creates a barrier to heart regeneration. Here, we move beyond a correlation by demonstrating that experimental polyploidization of zebrafish cardiomyocytes is sufficient to suppress their proliferative potential during regeneration. Initially, we determined that zebrafish myocardium becomes susceptible to polyploidization upon transient cytokinesis inhibition mediated by dominant-negative Ect2. Using a transgenic strategy, we generated adult animals containing mosaic hearts composed of differentially labeled diploid and polyploid-enriched cardiomyocyte populations. Diploid cardiomyocytes outcompeted their polyploid neighbors in producing regenerated heart muscle. Moreover, hearts composed of equivalent proportions of diploid and polyploid cardiomyocytes failed to regenerate altogether, demonstrating that a critical percentage of diploid cardiomyocytes is required to achieve heart regeneration. Our data identify cardiomyocyte polyploidization as a barrier to heart regeneration and suggest that mobilizing rare diploid cardiomyocytes in the human heart will improve its regenerative capacity. Copyright © 2018 Elsevier Inc. All rights reserved.

Noninvasive Measurement of EKG Properties of 3D Artificial Heart Muscle

Directory of Open Access Journals (Sweden)

Betsy H. Salazar

2017-06-01

Full Text Available Developing and testing a custom fabricated 16-electrode noninvasive direct contact system was necessary to assess the electrical properties of bioengineered heart muscle and to further evaluate the efficacy of cardiac constructs. By culturing neonatal rat primary cardiac cells on a fibrin gel, we constructed 3D artificial heart muscle (3D-AHM, as described in previous studies, which were used in validating this novel system. Electrical and mechanical functional assessment of the tissues was performed, which yielded contractile forces of the tissues, electrical field potential characteristics, and tissue conduction velocities (CV (20–170 cm/s. Immunohistological evaluation revealed the formation of cardiac tissue structures and cardiomyocyte proliferation. EKG data analysis also yielded time delays between signals in the range of 0–38 ms with electrical maps showing some evidence of synchronous contraction within the fabricated tissues. This study demonstrates the effectiveness and practicality of our novel EKG measuring system to acquire distinct electrical metrics of 3D-AHM, which will aid in increasing the viability and applicability of cardiac tissue constructs.

Stem cell therapy for end-stage heart failure : indispensable role for the cell?

NARCIS (Netherlands)

Vrijsen, K. R.; Chamuleau, S. A. J.; Noort, W. A.; Doevendans, P. A.; Sluijter, J. P. G.

2009-01-01

Purpose of review For heart failure patients, the urgent need for heart transplantation exceeds the availability of donor hearts. Therefore, cell transplantation has emerged as an interesting and potential solution. This review will focus on the capability of different types of stem cells to

Renal Denervation for Chronic Heart Failure: Background and Pathophysiological Rationale.

Science.gov (United States)

Böhm, Michael; Ewen, Sebastian; Mahfoud, Felix

2017-01-01

The activation of the sympathetic nervous system is associated with cardiovascular hospitalizations and death in heart failure. Renal denervation has been shown to effectively reduce sympathetic overdrive in certain patients with uncontrolled hypertension. Pilot trials investigating renal denervation as a potential treatment approach for heart failure were initiated. Heart failure comorbidities like obstructive sleep apnea, metabolic syndrome and arrhythmias could also be targets for renal denervation, because these occurrences are also mediated by the activation of the sympathetic nervous system. Therefore, renal denervation in heart failure is worthy of further investigation, although its effectiveness still has to be proven. Herein, we describe the pathophysiological rationale and the effect of renal denervation on surrogates of the heart failure syndrome.

EDITORIAL: Focus on Heart and Mind

Science.gov (United States)

Bodenschatz, Eberhard; Wolf, Fred

2008-01-01

Among the organs of our body, the function of heart and brain are unique in that their operation emerges from the collective dynamics of millions of strongly interacting cells well organized in their geometrical structure and connectivity. In the heart muscle the propagation of a nonlinear wave pulse, the cardiac action potential, controls the contraction. Usually the propagation is well-organized both in space and time and the heart functions as an efficient biological pump. Instabilities triggered by diseased tissue but also by dynamical heterogeneities, may, however, induce cardiac arrhythmia and fibrillation, where the pacemaker looses control to dynamically generated, high-frequency self-excitation of the muscle. In this state the coherence of contraction is lost and may lead within minutes to death. The appearance of arrhythmias can be associated with topological singularities, the so called spiral or scroll waves, and how the occurrence of this malfunctioning pattern-formation process can be understood is a dominant subject of current research. This is all the more important as cardiac arrhythmias and fibrillation are the main cause of premature death in the developed world. Similarly, in the brain the propagation of a nonlinear wave pulse, namely the neural action potential, is at the basis of the computational and memory power of the brain, i.e. what determines the workings of our 'minds'. Here, however, due to the high degree of interconnectivity and topological complexity of the neuronal network, the coordinated activity of millions of interacting nerve cells is more complex, although the basic principles of action potential generation at the level of each cell are quite similar. The currently emerging field of network dynamical systems is largely driven by the mathematical challenge and the steady stream of novel dynamical phenomena that results from the interplay of local nonlinear dynamics and complex network structure in models of biological neuronal

Heart Diseases

Science.gov (United States)

... you're like most people, you think that heart disease is a problem for others. But heart disease is the number one killer in the ... of disability. There are many different forms of heart disease. The most common cause of heart disease ...

Heart Transplantation

Science.gov (United States)

A heart transplant removes a damaged or diseased heart and replaces it with a healthy one. The healthy heart comes from a donor who has died. It is the last resort for people with heart failure when all other treatments have failed. The ...

MHODE: a local-homogeneity theory for improved source-parameter estimation of potential fields

Science.gov (United States)

Fedi, Maurizio; Florio, Giovanni; Paoletti, Valeria

2015-08-01

We describe a multihomogeneity theory for source-parameter estimation of potential fields. Similar to what happens for random source models, where the monofractal scaling-law has been generalized into a multifractal law, we propose to generalize the homogeneity law into a multihomogeneity law. This allows a theoretically correct approach to study real-world potential fields, which are inhomogeneous and so do not show scale invariance, except in the asymptotic regions (very near to or very far from their sources). Since the scaling properties of inhomogeneous fields change with the scale of observation, we show that they may be better studied at a set of scales than at a single scale and that a multihomogeneous model is needed to explain its complex scaling behaviour. In order to perform this task, we first introduce fractional-degree homogeneous fields, to show that: (i) homogeneous potential fields may have fractional or integer degree; (ii) the source-distributions for a fractional-degree are not confined in a bounded region, similarly to some integer-degree models, such as the infinite line mass and (iii) differently from the integer-degree case, the fractional-degree source distributions are no longer uniform density functions. Using this enlarged set of homogeneous fields, real-world anomaly fields are studied at different scales, by a simple search, at any local window W, for the best homogeneous field of either integer or fractional-degree, this yielding a multiscale set of local homogeneity-degrees and depth estimations which we call multihomogeneous model. It is so defined a new technique of source parameter estimation (Multi-HOmogeneity Depth Estimation, MHODE), permitting retrieval of the source parameters of complex sources. We test the method with inhomogeneous fields of finite sources, such as faults or cylinders, and show its effectiveness also in a real-case example. These applications show the usefulness of the new concepts, multihomogeneity and

Quark number density and susceptibility calculation with one correction in mean field potential

International Nuclear Information System (INIS)

Singh, S. Somorendro

2016-01-01

We calculate quark number density and susceptibility of a model which has one loop correction in mean field potential. The calculation shows continuous increasing in the number density and susceptibility up to the temperature T = 0.4 GeV. Then the value of number density and susceptibility approach to the lattice result for higher value of temperature. The result indicates that the calculated values of the model fit well and the result increase the temperature to reach the lattice data with the one loop correction in the mean field potential. (author)

Green's functions potential fields on surfaces

CERN Document Server

Melnikov, Yuri A

2017-01-01

This book is comprehensive in its classical mathematical physics presentation, providing the reader with detailed instructions for obtaining Green's functions from scratch. Green's functions is an instrument easily accessible to practitioners who are engaged in design and exploitation of machines and structures in modern engineering practice. To date, there are no books available on the market that are devoted to the Green's function formalism for equations covered in this volume. The reader, with an undergraduate background in applied mathematics, can become an active user of the Green's function approach. For the first time, Green's functions are discussed for a specific class of problems dealing with potential fields induced in thin-wall structures and therefore, the reader will have first-hand access to a novel issue. This Work is accessible to researchers in applied mathematics, mechanics, and relevant disciplines such as engineering, as well as to upper level undergraduates and graduate students.

Vasopressin and Vasopressin Antagonists in Heart Failure

DEFF Research Database (Denmark)

Vishram-Nielsen, Julie K; Gustafsson, Finn

2017-01-01

Despite the introduction of multiple new pharmacological agents over the past three decades in the field of heart failure (HF), overall prognosis remains poor. Hyponatremia is prevalent in HF patients and has been suggested as a contributor to poor response to standard therapy. Elevated levels...... by the V2 receptors in the renal collecting tubules. The optimal use of VRAs is yet to be determined, especially in patients with congestive HF. Although long-term effects on improvement in mortality have not been shown in the Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study with Tolvaptan...

2013 update on congenital heart disease, clinical cardiology, heart failure, and heart transplant.

Science.gov (United States)

Subirana, M Teresa; Barón-Esquivias, Gonzalo; Manito, Nicolás; Oliver, José M; Ripoll, Tomás; Lambert, Jose Luis; Zunzunegui, José L; Bover, Ramon; García-Pinilla, José Manuel

2014-03-01

This article presents the most relevant developments in 2013 in 3 key areas of cardiology: congenital heart disease, clinical cardiology, and heart failure and transplant. Within the area of congenital heart disease, we reviewed contributions related to sudden death in adult congenital heart disease, the importance of specific echocardiographic parameters in assessing the systemic right ventricle, problems in patients with repaired tetralogy of Fallot and indication for pulmonary valve replacement, and confirmation of the role of specific factors in the selection of candidates for Fontan surgery. The most recent publications in clinical cardiology include a study by a European working group on correct diagnostic work-up in cardiomyopathies, studies on the cost-effectiveness of percutaneous aortic valve implantation, a consensus document on the management of type B aortic dissection, and guidelines on aortic valve and ascending aortic disease. The most noteworthy developments in heart failure and transplantation include new American guidelines on heart failure, therapeutic advances in acute heart failure (serelaxin), the management of comorbidities such as iron deficiency, risk assessment using new biomarkers, and advances in ventricular assist devices. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

Coppicing potential of Eucalyptus nitens : results from a field survey ...

African Journals Online (AJOL)

In order to determine factors which could have a positive influence on the coppicing potential of Eucalyptus nitens , a field survey was carried out at Draycott, near Estcourt in the KwaZulu-Natal Midlands. Five measures of the ability to coppice (stump survival, height of coppice, number of dominant shoots, coppicing ...

Pediatric heart surgery

Science.gov (United States)

Heart surgery - pediatric; Heart surgery for children; Acquired heart disease; Heart valve surgery - children ... There are many kinds of heart defects. Some are minor, and others are more serious. Defects can occur inside the heart or in the large blood vessels ...

Hypertrophy of neurons within cardiac ganglia in human, canine, and rat heart failure: the potential role of nerve growth factor.

Science.gov (United States)

Singh, Sanjay; Sayers, Scott; Walter, James S; Thomas, Donald; Dieter, Robert S; Nee, Lisa M; Wurster, Robert D

2013-08-19

Autonomic imbalances including parasympathetic withdrawal and sympathetic overactivity are cardinal features of heart failure regardless of etiology; however, mechanisms underlying these imbalances remain unknown. Animal model studies of heart and visceral organ hypertrophy predict that nerve growth factor levels should be elevated in heart failure; whether this is so in human heart failure, though, remains unclear. We tested the hypotheses that neurons in cardiac ganglia are hypertrophied in human, canine, and rat heart failure and that nerve growth factor, which we hypothesize is elevated in the failing heart, contributes to this neuronal hypertrophy. Somal morphology of neurons from human (579.54±14.34 versus 327.45±9.17 μm(2); Phearts (767.80±18.37 versus 650.23±9.84 μm(2); Pneurons from spontaneously hypertensive rat hearts (327.98±3.15 versus 271.29±2.79 μm(2); Pneurons in cardiac ganglia compared with controls. Western blot analysis shows that nerve growth factor levels in the explanted, failing human heart are 250% greater than levels in healthy donor hearts. Neurons from cardiac ganglia cultured with nerve growth factor are significantly larger and have greater dendritic arborization than neurons in control cultures. Hypertrophied neurons are significantly less excitable than smaller ones; thus, hypertrophy of vagal postganglionic neurons in cardiac ganglia would help to explain the parasympathetic withdrawal that accompanies heart failure. Furthermore, our observations suggest that nerve growth factor, which is elevated in the failing human heart, causes hypertrophy of neurons in cardiac ganglia.

Total Artificial Heart as Bridge to Heart Transplantation in Chagas Cardiomyopathy: Case Report.

Science.gov (United States)

Ruzza, A; Czer, L S C; De Robertis, M; Luthringer, D; Moriguchi, J; Kobashigawa, J; Trento, A; Arabia, F

2016-01-01

Chagas disease (CD) is becoming an increasingly recognized cause of dilated cardiomyopathy outside of Latin America, where it is endemic, due to population shifts and migration. Heart transplantation (HTx) is a therapeutic option for end-stage cardiomyopathy due to CD, but may be considered a relative contraindication due to potential reactivation of the causative organism with immunosuppression therapy. The total artificial heart (TAH) can provide mechanical circulatory support in decompensated patients with severe biventricular dysfunction until the time of HTx, while avoiding immunosuppressive therapy and removing the organ most affected by the causative organism. We report herein a patient with CD and severe biventricular dysfunction, who had mechanical circulatory support with a TAH for more than 6 months, followed by successful orthotopic HTx and treatment with benznidazole for 3 months. The patient had no evidence of recurrent disease in the transplanted heart based on endomyocardial biopsy up to 1 year post-transplantation, and remains alive more than 30 months after insertion of a TAH and 24 months after HTx. Copyright © 2016 Elsevier Inc. All rights reserved.

Vacuum stability of a general scalar potential of a few fields

Energy Technology Data Exchange (ETDEWEB)

Kannike, Kristjan [NICPB, Tallinn (Estonia)

2016-06-15

We calculate analytical vacuum stability or bounded from below conditions for general scalar potentials of a few fields. After a brief review of copositivity, we show how to find positivity conditions for more complicated potentials. We discuss the vacuum stability conditions of the general potential of two real scalars, without and with the Higgs boson included in the potential. As further examples, we give explicit vacuum stability conditions for the two Higgs doublet model with no explicit CP breaking, and for the Z{sub 3} scalar dark matter with an inert doublet and a complex singlet. We give a short overview of positivity conditions for tensors of quartic couplings via tensor eigenvalues. (orig.)

Syndecans in heart fibrosis.

Science.gov (United States)

Lunde, Ida G; Herum, Kate M; Carlson, Cathrine C; Christensen, Geir

2016-09-01

Heart disease is a deadly syndrome affecting millions worldwide. It reflects an unmet clinical need, and the disease mechanisms are poorly understood. Cardiac fibrosis is central to heart disease. The four-membered family of transmembrane proteoglycans, syndecan-1 to -4, is believed to regulate fibrosis. We review the current literature concerning syndecans in cardiac fibrosis. Syndecan expression is up-regulated in response to pro-inflammatory stimuli in various forms of heart disease with fibrosis. Mice lacking syndecan-1 and -4 show reduced activation of pro-fibrotic signaling and increased cardiac rupture upon infarction indicating an important role for these molecules. Whereas the short cytoplasmic tail of syndecans regulates signaling, their extracellular part, substituted with heparan sulfate glycosaminoglycan chains, binds a plethora of extracellular matrix (ECM) molecules involved in fibrosis, e.g., collagens, growth factors, cytokines, and immune cell adhesion proteins. Full-length syndecans induce pro-fibrotic signaling, increasing the expression of collagens, myofibroblast differentiation factors, ECM enzymes, growth factors, and immune cell adhesion molecules, thereby also increasing cardiac stiffness and preventing cardiac rupture. Upon pro-inflammatory stimuli, syndecan ectodomains are enzymatically released from heart cells (syndecan shedding). Shed ectodomains affect the expression of ECM molecules, promoting ECM degradation and cardiac rupture upon myocardial infarction. Blood levels of shed syndecan-1 and -4 ectodomains are associated with hospitalization, mortality, and heart remodeling in patients with heart failure. Improved understanding of syndecans and their modifying enzymes in cardiac fibrosis might contribute to the development of compounds with therapeutic potential, and enzymatically shed syndecan ectodomains might constitute a future prognostic tool for heart diseases with fibrosis. Graphical Abstract Graphical abstract summarizing

An open access database for the evaluation of heart sound algorithms.

Science.gov (United States)

Liu, Chengyu; Springer, David; Li, Qiao; Moody, Benjamin; Juan, Ricardo Abad; Chorro, Francisco J; Castells, Francisco; Roig, José Millet; Silva, Ikaro; Johnson, Alistair E W; Syed, Zeeshan; Schmidt, Samuel E; Papadaniil, Chrysa D; Hadjileontiadis, Leontios; Naseri, Hosein; Moukadem, Ali; Dieterlen, Alain; Brandt, Christian; Tang, Hong; Samieinasab, Maryam; Samieinasab, Mohammad Reza; Sameni, Reza; Mark, Roger G; Clifford, Gari D

2016-12-01

In the past few decades, analysis of heart sound signals (i.e. the phonocardiogram or PCG), especially for automated heart sound segmentation and classification, has been widely studied and has been reported to have the potential value to detect pathology accurately in clinical applications. However, comparative analyses of algorithms in the literature have been hindered by the lack of high-quality, rigorously validated, and standardized open databases of heart sound recordings. This paper describes a public heart sound database, assembled for an international competition, the PhysioNet/Computing in Cardiology (CinC) Challenge 2016. The archive comprises nine different heart sound databases sourced from multiple research groups around the world. It includes 2435 heart sound recordings in total collected from 1297 healthy subjects and patients with a variety of conditions, including heart valve disease and coronary artery disease. The recordings were collected from a variety of clinical or nonclinical (such as in-home visits) environments and equipment. The length of recording varied from several seconds to several minutes. This article reports detailed information about the subjects/patients including demographics (number, age, gender), recordings (number, location, state and time length), associated synchronously recorded signals, sampling frequency and sensor type used. We also provide a brief summary of the commonly used heart sound segmentation and classification methods, including open source code provided concurrently for the Challenge. A description of the PhysioNet/CinC Challenge 2016, including the main aims, the training and test sets, the hand corrected annotations for different heart sound states, the scoring mechanism, and associated open source code are provided. In addition, several potential benefits from the public heart sound database are discussed.

Classification of hemispheric monthly mean stratospheric potential vorticity fields

Directory of Open Access Journals (Sweden)

R. Huth

Full Text Available Monthly mean NCEP reanalysis potential vorticity fields at the 650 K isentropic level over the Northern and Southern Hemispheres between 1979 and 1997 were studied using multivariate analysis tools. Principal component analysis in the T-mode was applied to demonstrate the validity of such statistical techniques for the study of stratospheric dynamics and climatology. The method, complementarily applied to both the raw and anomaly fields, was useful in determining and classifying the characteristics of winter and summer PV fields on both hemispheres, in particular, the well-known differences in the behaviour and persistence of the polar vortices. It was possible to identify such features as sudden warming events in the Northern Hemisphere and final warming dates in both hemispheres. The stratospheric impact of other atmospheric processes, such as volcanic eruptions, also identified though the results, must be viewed at this stage as tentative. An interesting change in behaviour around 1990 was detected over both hemispheres.

Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; general circulation; climatology

Heart transplantation and arterial elasticity

Directory of Open Access Journals (Sweden)

Colvin-Adams M

2013-12-01

healthy population. Furthermore, cardiac allograft vasculopathy is associated with a significant reduction in SAE, suggesting a potential use in screening heart transplant recipients at risk for developing this complication.Keywords: heart transplant, endothelial function, arterial elasticity, cardiac allograft vasculopathy

Combined heart-kidney transplantation after total artificial heart insertion.

Science.gov (United States)

Ruzza, A; Czer, L S C; Ihnken, K A; Sasevich, M; Trento, A; Ramzy, D; Esmailian, F; Moriguchi, J; Kobashigawa, J; Arabia, F

2015-01-01

We present the first single-center report of 2 consecutive cases of combined heart and kidney transplantation after insertion of a total artificial heart (TAH). Both patients had advanced heart failure and developed dialysis-dependent renal failure after implantation of the TAH. The 2 patients underwent successful heart and kidney transplantation, with restoration of normal heart and kidney function. On the basis of this limited experience, we consider TAH a safe and feasible option for bridging carefully selected patients with heart and kidney failure to combined heart and kidney transplantation. Recent FDA approval of the Freedom driver may allow outpatient management at substantial cost savings. The TAH, by virtue of its capability of providing pulsatile flow at 6 to 10 L/min, may be the mechanical circulatory support device most likely to recover patients with marginal renal function and advanced heart failure. Copyright © 2015 Elsevier Inc. All rights reserved.

Activation delay-induced mechanical dyssynchrony in single-ventricle heart disease

DEFF Research Database (Denmark)

Forsha, Daniel; Risum, Niels; Barker, Piers

2017-01-01

We present the case of an infant with a single functional ventricle who developed ventricular dysfunction and heart failure due to an electrical activation delay and dyssynchrony. Earlier recognition of this potentially reversible aetiology may have changed her poor outcome.......We present the case of an infant with a single functional ventricle who developed ventricular dysfunction and heart failure due to an electrical activation delay and dyssynchrony. Earlier recognition of this potentially reversible aetiology may have changed her poor outcome....

New pharmacological and technological management strategies in heart failure

Directory of Open Access Journals (Sweden)

Chaudhry SP

2017-03-01

Full Text Available Sunit-Preet Chaudhry,1 Garrick C Stewart2 1Division of Cardiology, St Vincent Indianapolis, Indianapolis, IN, 2Division of Cardiovascular Medicine, Center for Advanced Heart Disease, Brigham and Women’s Hospital, Boston, MA, USA Abstract: Heart failure is a complex clinical syndrome resulting from impairment of ventricular filling or ejection of blood associated with symptoms of dyspnea, fatigue, as well as peripheral and/or pulmonary edema. This syndrome is progressive and characterized by worsening quality of life despite escalating levels of care, affecting 5.7 million Americans with an annual cost of over $30 billion US dollars. Treatment for this syndrome has evolved over three distinct eras: the nonpharmacological era, the pharmacological era, and the device era, with the focus shifting from symptomatic relief to decreasing morbidity and mortality. Over the past 10 years, the field has undergone a renaissance, with the development of new pharmacologic, hemodynamic monitoring, and device therapies proven to improve outcomes in patients with heart failure. This article will review several recent innovations in the management of patients with heart failure. Keywords: heart failure, heart-assist devices, disease management

Recruitment of aged donor heart with pharmacological stress echo. A case report

Directory of Open Access Journals (Sweden)

Bombardini Tonino

2006-01-01

Full Text Available Abstract Background The heart transplant is a treatment of the heart failure, which is not responding to medications, and its efficiency is already proved: unfortunately, organ donation is a limiting step of this life-saving procedure. To counteract heart donor shortage, we should screen aged potential donor hearts for initial cardiomyopathy and functionally significant coronary artery disease. Donors with a history of cardiac disease are generally excluded. Coronary angiography is recommended for most male donors older than 45 years and female donors older than 50 years to evaluate coronary artery stenoses. A simpler way to screen aged potential donor hearts for initial cardiomyopathy and functionally significant coronary artery disease should be stress echocardiography. Case report A marginal donor (A 57 year old woman meeting legal requirements for brain death underwent a transesophageal (TE Dipyridamole stress echo (6 minutes accelerated protocol to rule out moderate or severe heart and coronary artery disease. Wall motion was normal at baseline and at peak stress (WMSI = 1 at baseline and peak stress, without signs of stress inducible ischemia. The pressure/volume ratio was 9.6 mmHg/ml/m2 at baseline, increasing to 14 mmHg/ml/m2 at peak stress, demonstrating absence of latent myocardial dysfunction. The marginal donor heart was transplanted to a recipient "marginal" for co-morbidity ( a 63 year old man with multiple myeloma and cardiac amyloidosis , chronic severe heart failure, NYHA class IV. Postoperative treatment and early immunosuppressant regimen were performed according to standard protocols. The transplanted heart was assessed normal for dimensions and ventricular function at transthoracic (TT echocardiography on post-transplant day 7. Coronary artery disease was ruled out at coronary angiography one month after transplant; left ventriculography showed normal global and segmental LV function of the transplanted heart. Conclusion For

Heart irradiation as a risk factor for radiation pneumonitis

International Nuclear Information System (INIS)

Huang, Ellen X.; El Naqa, Issam; Deasy, Joseph O.; Bradley, Jeffrey D.; Hope, Andrew J.; Lindsay, Patricia E.; Trovo, Marco

2011-01-01

Purpose. To investigate the potential role of incidental heart irradiation on the risk of radiation pneumonitis (RP) for patients receiving definitive radiation therapy for non-small-cell lung cancer (NSCLC). Material and methods. Two hundred and nine patient datasets were available for this study. Heart and lung dose-volume parameters were extracted for modeling, based on Monte Carlo-based heterogeneity corrected dose distributions. Clinical variables tested included age, gender, chemotherapy, pre-treatment weight-loss, performance status, and smoking history. The risk of RP was modeled using logistic regression. Results. The most significant univariate variables were heart related, such as heart heart V65 (percent volume receiving at least 65 Gy) (Spearman Rs = 0.245, p < 0.001). The best-performing logistic regression model included heart D10 (minimum dose to the hottest 10% of the heart), lung D35, and maximum lung dose (Spearman Rs 0.268, p < 0.0001). When classified by predicted risk, the RP incidence ratio between the most and least risky 1/3 of treatments was 4.8. The improvement in risk modeling using lung and heart variables was better than using lung variables alone. Conclusions. These results suggest a previously unsuspected role of heart irradiation in many cases of RP

What Is New in Heart Failure Management in 2017? Update on ACC/AHA Heart Failure Guidelines.

Science.gov (United States)

Bozkurt, Biykem

2018-04-17

The goal of this paper is to provide a summary of the new recommendations in the most recent 2017 ACC/AHA/HFSA Focused Update of the 2013 ACCF/AHA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Failure Society of America. The intent is to provide the background and the supporting evidence for the recommendations and to provide practical guidance for management strategies in treatment of heart failure patients. In the 2017 ACC/AHA/HFSA Focused Update of HF guidelines, important additions include new information on biomarkers, specifically on the topics of the diagnostic, prognostic role of natriuretic peptides in heart failure, and the role of natriuretic peptides in screening in patients high risk for HF and prevention of HF. There are important recommendations for treatment of patients with HF with reduced EF (HFrEF), including the beneficial role of angiotensin receptor blocker and neprilysin inhibition (ARNI) treatment in reducing outcomes including mortality, ivabradine in reducing heart failure hospitalizations in stable HFrEF patients with sinus rhythm and heart rate ≥ 70 bpm despite β-blockers. In patients with HF with preserved EF (HFpEF), though there are no studies demonstrating survival benefit, potential benefit with aldosterone antagonism in reducing HF hospitalizations is noted. In treatment of comorbidities, optimization of blood pressure control to less than 130 mmHg is recommended in hypertensive patients to prevent HF or in patients with hypertension and HFrEF or HFpEF. In addition to recognition on the potential role of treatment of iron deficiency anemia to improve symptoms and functional capacity, caution against use of adaptive servo-ventilation in patients with HFrEF and central sleep apnea and against use of erythropoietin stimulating agents in patients with HFrEF is provided. There are new treatment

Emerging role of liver X receptors in cardiac pathophysiology and heart failure.

Science.gov (United States)

Cannon, Megan V; van Gilst, Wiek H; de Boer, Rudolf A

2016-01-01

Liver X receptors (LXRs) are master regulators of metabolism and have been studied for their pharmacological potential in vascular and metabolic disease. Besides their established role in metabolic homeostasis and disease, there is mounting evidence to suggest that LXRs may exert direct beneficial effects in the heart. Here, we aim to provide a conceptual framework to explain the broad mode of action of LXRs and how LXR signaling may be an important local and systemic target for the treatment of heart failure. We discuss the potential role of LXRs in systemic conditions associated with heart failure, such as hypertension, diabetes, and renal and vascular disease. Further, we expound on recent data that implicate a direct role for LXR activation in the heart, for its impact on cardiomyocyte damage and loss due to ischemia, and effects on cardiac hypertrophy, fibrosis, and myocardial metabolism. Taken together, the accumulating evidence supports the notion that LXRs may represent a novel therapeutic target for the treatment of heart failure.

Electric Potential and Electric Field Imaging with Dynamic Applications: 2017 Research Award Innovation

Science.gov (United States)

Generazio, Ed

2017-01-01

The technology and methods for remote quantitative imaging of electrostatic potentials and electrostatic fields in and around objects and in free space is presented. Electric field imaging (EFI) technology may be applied to characterize intrinsic or existing electric potentials and electric fields, or an externally generated electrostatic field may be used for illuminating volumes to be inspected with EFI. The baseline sensor technology (e-Sensor) and its construction, optional electric field generation (quasi-static generator), and current e- Sensor enhancements (ephemeral e-Sensor) are discussed. Critical design elements of current linear and real-time two-dimensional (2D) measurement systems are highlighted, and the development of a three dimensional (3D) EFI system is presented. Demonstrations for structural, electronic, human, and memory applications are shown. Recent work demonstrates that phonons may be used to create and annihilate electric dipoles within structures. Phonon induced dipoles are ephemeral and their polarization, strength, and location may be quantitatively characterized by EFI providing a new subsurface Phonon-EFI imaging technology. Initial results from real-time imaging of combustion and ion flow, and their measurement complications, will be discussed. These new EFI capabilities are demonstrated to characterize electric charge distribution creating a new field of study embracing areas of interest including electrostatic discharge (ESD) mitigation, crime scene forensics, design and materials selection for advanced sensors, combustion science, on-orbit space potential, container inspection, remote characterization of electronic circuits and level of activation, dielectric morphology of structures, tether integrity, organic molecular memory, atmospheric science, and medical diagnostic and treatment efficacy applications such as cardiac polarization wave propagation and electromyography imaging.

Surgical approach to end-stage heart failure.

Science.gov (United States)

Klotz, Stefan; Scheld, Hans H

2011-02-01

End-stage heart failure is a challenging disease with growing incidence. With decreasing heart transplant rates worldwide organ preserving therapies become, again, of interest. The purpose of the present review is to examine the potential challenges of surgical therapies in patients with end-stage heart failure. The gold-standard for end-stage heart failure is and will be cardiac transplantation. However, due to organ shortage this therapy is limited to a few patients. Therefore implantation of ventricular assist devices (VADs) or long-term minimal-invasive partial support devices will increase. Improvements in device design with smaller devices, easier implantation techniques, and modified anticoagulation outcome and long-term success will likely improve. In addition, good quality of life as destination therapy is almost available. Organ conservation surgery (coronary artery bypass grafting and surgical ventricular restoration or surgical repair of mitral valve regurgitation) in end-stage heart failure patients could not prove the expected results. Transcatheter or minimal-invasive approaches of these therapies might become routine in the near future. Due to the overwhelming outcome rates, cardiac transplantation is the most established surgical therapy for end-stage heart failure. VAD therapy is increasing and minimized VADs might further open the market for destination therapy/permanent support.

Exact time-dependent exchange-correlation potentials for strong-field electron dynamics

International Nuclear Information System (INIS)

Lein, Manfred; Kuemmel, Stephan

2005-01-01

By solving the time-dependent Schroedinger equation and inverting the time-dependent Kohn-Sham scheme we obtain the exact time-dependent exchange-correlation potential of density-functional theory for the strong-field dynamics of a correlated system. We demonstrate that essential features of the exact exchange-correlation potential can be related to derivative discontinuities in stationary density-functional theory. Incorporating the discontinuity in a time-dependent density-functional calculation greatly improves the description of the ionization process

Healthy Body, Happy Heart: Improve Your Heart Health

Science.gov (United States)

... November 2017 Print this issue Healthy Body, Happy Heart Improve Your Heart Health En español Send us your comments Every moment of the day, your heart is pumping blood throughout your body. In silent ...

Renal Denervation for Chronic Heart Failure: Background and Pathophysiological Rationale

Science.gov (United States)

Ewen, Sebastian; Mahfoud, Felix

2017-01-01

The activation of the sympathetic nervous system is associated with cardiovascular hospitalizations and death in heart failure. Renal denervation has been shown to effectively reduce sympathetic overdrive in certain patients with uncontrolled hypertension. Pilot trials investigating renal denervation as a potential treatment approach for heart failure were initiated. Heart failure comorbidities like obstructive sleep apnea, metabolic syndrome and arrhythmias could also be targets for renal denervation, because these occurrences are also mediated by the activation of the sympathetic nervous system. Therefore, renal denervation in heart failure is worthy of further investigation, although its effectiveness still has to be proven. Herein, we describe the pathophysiological rationale and the effect of renal denervation on surrogates of the heart failure syndrome. PMID:28154583

Transmural recording of shock potential gradient fields, early postshock activations, and refibrillation episodes associated with external defibrillation of long-duration ventricular fibrillation in swine.

Science.gov (United States)

Allred, James D; Killingsworth, Cheryl R; Allison, J Scott; Dosdall, Derek J; Melnick, Sharon B; Smith, William M; Ideker, Raymond E; Walcott, Gregory P

2008-11-01

Knowledge of the shock potential gradient (nablaV) and postshock activation is limited to internal defibrillation of short-duration ventricular fibrillation (SDVF). The purpose of this study was to determine these variables after external defibrillation of long-duration VF (LDVF). In six pigs, 115-20 plunge needles with three to six electrodes each were inserted to record throughout both ventricles. After the chest was closed, the biphasic defibrillation threshold (DFT) was determined after 20 seconds of SDVF with external defibrillation pads. After 7 minutes of LDVF, defibrillation shocks that were less than or equal to the SDVF DFT strength were given. For DFT shocks (1632 +/- 429 V), the maximum minus minimum ventricular voltage (160 +/- 100 V) was 9.8% of the shock voltage. Maximum cardiac nablaV (28.7 +/- 17 V/cm) was 4.7 +/- 2.0 times the minimum nablaV (6.2 +/- 3.5 V/cm). Although LDVF did not increase the DFT in five of the six pigs, it significantly lengthened the time to earliest postshock activation following defibrillation (1.6 +/- 2.2 seconds for SDVF and 4.9 +/- 4.3 seconds for LDVF). After LDVF, 1.3 +/- 0.8 episodes of spontaneous refibrillation occurred per animal, but there was no refibrillation after SDVF. Compared with previous studies of internal defibrillation, during external defibrillation much less of the shock voltage appears across the heart and the shock field is much more even; however, the minimum nablaV is similar. Compared with external defibrillation of SDVF, the biphasic external DFT for LDVF is not increased; however, time to earliest postshock activation triples. Refibrillation is common after LDVF but not after SDVF in these normal hearts, indicating that LDVF by itself can cause refibrillation without requiring preexisting heart disease.

Drift motion of a charged particle in the crossed axial magnetic and radial electric fields, and the electric field of a rotating potential wave

International Nuclear Information System (INIS)

Eliseev, Yu.N.; Stepanov, K.N.

1983-01-01

In the drift motion approximation solution of the problem is obtained on the motion of a nonrelativistic charged particle in the crossed axial magnetic and radial electric fields, and the electric field of a rotating potential wave under cherenkov and modified cyclotron resonances. The static radial electric field potential is supposed to be close to the parabolic one. The drift motion equations and their integrals are preseOted. The experimentally obtained effect of plasma ionic component division in the crossed fields under the excitation of ion cyclotron oscillations is explained with the help of the theory developed in the paper

Coronary heart disease after radiotherapy for peptic ulcer disease

International Nuclear Information System (INIS)

Carr, Zhanat A.; Land, Charles E.; Kleinerman, Ruth A.; Weinstock, Robert W.; Stovall, Marilyn; Griem, Melvin L.; Mabuchi, Kiyohiko

2005-01-01

Purpose: To evaluate the risk of coronary heart disease (CHD) and cerebrovascular disease after radiotherapy (RT) for peptic ulcer disease. Methods and materials: Peptic ulcer disease patients treated with RT (n = 1859) or by other means (n = 1860) at the University of Chicago Medical Center between 1936 and 1965, were followed through 1997. The observed numbers of cause-specific deaths were compared with the expected numbers from the general population rates. During RT, 5% of the heart was in the treatment field and the remainder of the heart mostly received scattered radiation. A volume-weighted cardiac dose was computed to describe the average tissue dose to the entire organ. We used Cox proportional hazards regression analysis to analyze the CHD and cerebrovascular disease risk associated with RT, adjusting for confounding factors. Results: Greater than expected CHD mortality was observed among the irradiated patients. The irradiated patients received volume-weighted cardiac doses ranging from 1.6 to 3.9 Gy and the portion of the heart directly in the field received doses of 7.6-18.4 Gy. The CHD risk increased with the cardiac dose (p trend = 0.01). The cerebrovascular disease risk was not associated with the surrogate carotid dose. Conclusion: The excess CHD risk in patients undergoing RT for peptic ulcer disease decades previously indicates the need for long-term follow-up for cardiovascular disease after chest RT

Hydroxytyrosol and its complex forms (secoiridoids) modulate aorta and heart proteome in healthy rats: Potential cardio-protective effects.

Science.gov (United States)

Catalán, Úrsula; Rubió, Laura; López de Las Hazas, Maria-Carmen; Herrero, Pol; Nadal, Pedro; Canela, Núria; Pedret, Anna; Motilva, Maria-José; Solà, Rosa

2016-10-01

Hydroxytyrosol (HT) is the major phenolic compound in virgin olive oil (VOO) in both free and complex forms (secoiridoids; SEC). Proteomics of cardiovascular tissues such as aorta or heart represents a promising tool to uncover the mechanisms of action of phenolic compounds in healthy animals. Twelve female Wistar rats were separated into three groups: a standard diet and two diets supplemented in phenolic compounds (HT and SEC) adjusted to 5 mg/kg/day during 21 days. Proteomic analyses of aorta and heart tissues were performed by nano-LC and MS. Ingenuity Pathway Analysis was used to generate interaction networks. HT or SEC modulated aorta and heart proteome compared to the standard diet. The top-scored networks were related to Cardiovascular System. HT and SEC downregulated proteins related to proliferation and migration of endothelial cells and occlusion of blood vessels in aorta and proteins related to heart failure in heart tissue. SEC showed higher fold change values compared to HT, attributed to higher concentration of HT detected in heart tissue. Changes at proteomic level in cardiovascular tissues may partially account for the underlying mechanisms of VOO phenols cardiovascular protection being the SEC effects higher than free HT. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Influence of external magnetic field, finite-size effects and chemical potential on the phase transition of a complex scalar field

Energy Technology Data Exchange (ETDEWEB)

Cavalcanti, E.; Castro, E.; Malbouisson, A.P.C. [Centro Brasileiro de Pesquisas Fisicas/MCTI, Rio de Janeiro, RJ (Brazil); Linhares, C.A. [Universidade do Estado do Rio de Janeiro, Instituto de Fisica, Rio de Janeiro, RJ (Brazil)

2017-10-15

A scalar model is built, as a quantum field theory defined on a toroidal topology, to describe a phase transition in films subjected to periodic boundary conditions and influenced by an external and constant magnetic field. Criticality is studied and the relations between the critical temperature, the film thickness, the magnetic field strength and the chemical potential are investigated. Since the model describes a second-order phase transition a comparison with the Ginzburg-Landau theory is made. (orig.)

Spherical Magnetic Vortex in an External Potential Field: A Dissipative Contraction

Science.gov (United States)

Solov'ev, A. A.

2013-09-01

We consider the dissipative evolution of a spherical magnetic vortex with a force-free internal structure, located in a resistive medium and held in equilibrium by the potential external field. The magnetic field inside the sphere is force-free (the model of Chandrasekhar in Proc. Natl. Acad. Sci. 42, 1, 1956). Topologically, it is a set of magnetic toroids enclosed in spherical layers. A new exact MHD solution has been derived, describing a slow, uniform, radial compression of a magnetic spheroid under the pressure of an ambient field, when the plasma density and pressure are growing inside it. There is no dissipation in the potential field outside the sphere, but inside the sphere, where the current density can be high enough, the magnetic energy is continuously converted into heat. Joule dissipation lowers the magnetic pressure inside the sphere, which balances the pressure of the ambient field. This results in radial contraction of the magnetic sphere with a speed defined by the conductivity of the plasma and the characteristic spatial scale of the magnetic field inside the sphere. Formally, the sphere shrinks to zero within a finite time interval (magnetic collapse). The time of compression can be relatively small, within a day, even for a sphere with a radius of about 1 Mm, if the magnetic helicity trapped initially in the sphere (which is proportional to the number of magnetic toroids in the sphere) is quite large. The magnetic system is open along its axis of symmetry. On this axis, the magnetic and electric fields are strictly radial and sign-variable along the radius, so the plasma will be ejected along the axis of magnetic sphere outwards in both directions (as jets) at a rate much higher than the diffusive one, and the charged particles will be accelerated unevenly, in spurts, creating quasi-regular X-ray spikes. The applications of the solution to solar flares are discussed.

Electrophysiological and structural remodeling in heart failure modulate arrhythmogenesis. 2D simulation study.

Directory of Open Access Journals (Sweden)

Juan F Gomez

Full Text Available Heart failure is operationally defined as the inability of the heart to maintain blood flow to meet the needs of the body and it is the final common pathway of various cardiac pathologies. Electrophysiological remodeling, intercellular uncoupling and a pro-fibrotic response have been identified as major arrhythmogenic factors in heart failure.In this study we investigate vulnerability to reentry under heart failure conditions by incorporating established electrophysiological and anatomical remodeling using computer simulations.The electrical activity of human transmural ventricular tissue (5 cm × 5 cm was simulated using the human ventricular action potential model Grandi et al. under control and heart failure conditions. The MacCannell et al. model was used to model fibroblast electrical activity, and their electrotonic interactions with myocytes. Selected degrees of diffuse fibrosis and variations in intercellular coupling were considered and the vulnerable window (VW for reentry was evaluated following cross-field stimulation.No reentry was observed in normal conditions or in the presence of HF ionic remodeling. However, defined amount of fibrosis and/or cellular uncoupling were sufficient to elicit reentrant activity. Under conditions where reentry was generated, HF electrophysiological remodeling did not alter the width of the VW. However, intermediate fibrosis and cellular uncoupling significantly widened the VW. In addition, biphasic behavior was observed, as very high fibrotic content or very low tissue conductivity hampered the development of reentry. Detailed phase analysis of reentry dynamics revealed an increase of phase singularities with progressive fibrotic components.Structural remodeling is a key factor in the genesis of vulnerability to reentry. A range of intermediate levels of fibrosis and intercellular uncoupling can combine to favor reentrant activity.

Enlarged Heart

Science.gov (United States)

... rheumatic fever, a heart defect, infections (infectious endocarditis), connective tissue disorders, certain medications or radiation treatments for cancer, your heart may enlarge. Disease of the heart ...

The radiology of prosthetic heart valves

International Nuclear Information System (INIS)

Steiner, R.M.; Flicker, S.

1985-01-01

The development of prosthetic heart valves in the late 1950s ushered in a new era in the treatment of heart disease. The radiologist has an important role to play preoperatively in the diagnosis of valvular heart disease. Radiology is valuable in identification of the implanted prosthetic valve and recognition of complications associated with valve implantation. Radiologists must be familiar with the imaging techniques best suited to evaluate the function of the valve prosthesis in question. In this chapter the authors discuss the radiographic approach to the evaluation of the status of patients for valve replacement and the imaging problems peculiar to the types of valves in current use. The relative value of plain-film radiography, fluoroscopy, videorecording and cinerecording, and aortography is addressed, as well as the potential value of magnetic resonance imaging and subsecond dynamic computed tomography

Women's Heart Disease: Join the Heart Truth Community

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... this page please turn JavaScript on. Feature: Women's Heart Disease Join The Heart Truth Community Past Issues / Winter 2014 Table of Contents National Symbol The centerpiece of The Heart Truth ® is The Red Dress ® which was introduced ...

Gravitational and electromagnetic potentials of the stationary Einstein-Maxwell field equations

International Nuclear Information System (INIS)

Jones, T.C.

1979-01-01

Associated with the stationary Einstein-Maxwell field equations is an infinite hierarchy of potentials. The basic characteristics of these potentials are examined in general and then in greater detail for the particular case of the Reissner-Nordstrom metric. Thier essential utility in the process of solution generation is elucidated, and the necessary equations for solution generation are developed. Appropriate generating functions, which contain the complete infinite hierarchy of potentials, are developed and analyzed. Particular attention is paid to the inherent gauge freedom of these generating functions. Two methods of solution generation, which yield asymptotically flat solutions in vacuum, are generalized to include electromagnetism. One method, using potentials consistent with the Harrison transformation and the Reissner-Nordstrom metric, is discussed in detail, and its resultant difficulties are explored

Screening for Coronary Heart Disease with Electrocardiography

Science.gov (United States)

... resting and completely still or while you are exercising. ECG is used to see whether the heart is beating and functioning normally. Potential Benefits and Harms The Task Force reviewed evidence to ...

On-orbit assembly of a team of flexible spacecraft using potential field based method

Science.gov (United States)

Chen, Ti; Wen, Hao; Hu, Haiyan; Jin, Dongping

2017-04-01

In this paper, a novel control strategy is developed based on artificial potential field for the on-orbit autonomous assembly of four flexible spacecraft without inter-member collision. Each flexible spacecraft is simplified as a hub-beam model with truncated beam modes in the floating frame of reference and the communication graph among the four spacecraft is assumed to be a ring topology. The four spacecraft are driven to a pre-assembly configuration first and then to the assembly configuration. In order to design the artificial potential field for the first step, each spacecraft is outlined by an ellipse and a virtual leader of circle is introduced. The potential field mainly depends on the attitude error between the flexible spacecraft and its neighbor, the radial Euclidian distance between the ellipse and the circle and the classical Euclidian distance between the centers of the ellipse and the circle. It can be demonstrated that there are no local minima for the potential function and the global minimum is zero. If the function is equal to zero, the solution is not a certain state, but a set. All the states in the set are corresponding to the desired configurations. The Lyapunov analysis guarantees that the four spacecraft asymptotically converge to the target configuration. Moreover, the other potential field is also included to avoid the inter-member collision. In the control design of the second step, only small modification is made for the controller in the first step. Finally, the successful application of the proposed control law to the assembly mission is verified by two case studies.

Heart Health: Learn the Truth About Your Heart

Science.gov (United States)

... Bar Home Current Issue Past Issues Cover Story Heart Health Learn the Truth About Your Heart Past Issues / Winter 2009 Table of Contents For ... turn Javascript on. Photo: iStock February is American Heart Month. Now is the time to make sure ...

Pacing and Defibrillators in Complex Congenital Heart Disease

Science.gov (United States)

Chubb, Henry; O’Neill, Mark; Rosenthal, Eric

2016-01-01

Device therapy in the complex congenital heart disease (CHD) population is a challenging field. There is a myriad of devices available, but none designed specifically for the CHD patient group, and a scarcity of prospective studies to guide best practice. Baseline cardiac anatomy, prior surgical and interventional procedures, existing tachyarrhythmias and the requirement for future intervention all play a substantial role in decision making. For both pacing systems and implantable cardioverter defibrillators, numerous factors impact on the merits of system location (endovascular versus non-endovascular), lead positioning, device selection and device programming. For those with Fontan circulation and following the atrial switch procedure there are also very specific considerations regarding access and potential complications. This review discusses the published guidelines, device indications and the best available evidence for guidance of device implantation in the complex CHD population. PMID:27403295

A NEW TECHNIQUE FOR THE PHOTOSPHERIC DRIVING OF NON-POTENTIAL SOLAR CORONAL MAGNETIC FIELD SIMULATIONS

Energy Technology Data Exchange (ETDEWEB)

Weinzierl, Marion; Yeates, Anthony R. [Department of Mathematical Sciences, Durham University, South Road, Durham DH1 3LE (United Kingdom); Mackay, Duncan H. [School of Mathematics and Statistics, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9SS (United Kingdom); Henney, Carl J.; Arge, C. Nick, E-mail: marion.weinzierl@durham.ac.uk [Air Force Research Lab/Space Vehicles Directorate, 3550 Aberdeen Avenue SE, Kirtland AFB, NM (United States)

2016-05-20

In this paper, we develop a new technique for driving global non-potential simulations of the Sun’s coronal magnetic field solely from sequences of radial magnetic maps of the solar photosphere. A primary challenge to driving such global simulations is that the required horizontal electric field cannot be uniquely determined from such maps. We show that an “inductive” electric field solution similar to that used by previous authors successfully reproduces specific features of the coronal field evolution in both single and multiple bipole simulations. For these cases, the true solution is known because the electric field was generated from a surface flux-transport model. The match for these cases is further improved by including the non-inductive electric field contribution from surface differential rotation. Then, using this reconstruction method for the electric field, we show that a coronal non-potential simulation can be successfully driven from a sequence of ADAPT maps of the photospheric radial field, without including additional physical observations which are not routinely available.

Hypertrophy of Neurons Within Cardiac Ganglia in Human, Canine, and Rat Heart Failure: The Potential Role of Nerve Growth Factor

OpenAIRE

Singh, Sanjay; Sayers, Scott; Walter, James S.; Thomas, Donald; Dieter, Robert S.; Nee, Lisa M.; Wurster, Robert D.

2013-01-01

Background Autonomic imbalances including parasympathetic withdrawal and sympathetic overactivity are cardinal features of heart failure regardless of etiology; however, mechanisms underlying these imbalances remain unknown. Animal model studies of heart and visceral organ hypertrophy predict that nerve growth factor levels should be elevated in heart failure; whether this is so in human heart failure, though, remains unclear. We tested the hypotheses that neurons in cardiac ganglia are hyper...

Mending broken hearts : Cardiac regeneration in zebrafish

NARCIS (Netherlands)

kruse, fabian

2017-01-01

Cardiovascular disease is the leading global cause of death, accounting for more than 30% of all deaths. It claims more lives than all forms of cancer combined. Bearing these facts in mind, research in this field is direly needed. A heart attack, also known as myocardial infarction (MI), happens

Electromagnetic fields produced by incubators influence heart rate variability in newborns.

Science.gov (United States)

Bellieni, C V; Acampa, M; Maffei, M; Maffei, S; Perrone, S; Pinto, I; Stacchini, N; Buonocore, G

2008-07-01

Incubators are largely used to preserve preterm and sick babies from postnatal stressors, but their motors produce high electromagnetic fields (EMFs). Newborns are chronically exposed to these EMFs, but no studies about their effects on the fragile developing neonatal structure exist. To verify whether the exposure to incubator motor electric power may alter autonomous nervous system activity in newborns. Heart rate variability (HRV) of 43 newborns in incubators was studied. The study group comprised 27 newborns whose HRV was studied throughout three 5-minute periods: with incubator motor on, off, and on again, respectively. Mean HRV values obtained during each period were compared. The control group comprised 16 newborns with constantly unrecordable EMF and exposed to changes in background noise, similar to those provoked by the incubator motor. Mean (SD) total power and the high-frequency (HF) component of HRV increased significantly (from 87.1 (76.2) ms2 to 183.6 (168.5) ms2) and the mean low-frequency (LF)/HF ratio decreased significantly (from 2.0 (0.5) to 1.5 (0.6)) when the incubator motor was turned off. Basal values (HF = 107.1 (118.1) ms2 and LF/HF = 1.9 (0.6)) were restored when incubators were turned on again. The LF spectral component of HRV showed a statistically significant change only in the second phase of the experiment. Changes in background noise did not provoke any significant change in HRV. EMFs produced by incubators influence newborns' HRV, showing an influence on their autonomous nervous system. More research is needed to assess possible long-term consequences, since premature newborns may be exposed to these high EMFs for months.

The potential for satellite and marginal field developments on the Norwegian continental shelf

International Nuclear Information System (INIS)

Raustein, O.; Abrahamsen, L.E.; Einang, G.

1994-01-01

Norway is faced with decreasing field sizes in hostile waters. On the other hand, approximately 620 billion 1993-NOK have been invested in field installations and transport systems. These installations will have significant available processing and transport capacity in the future, and thus represent a valuable infrastructure. This paper describes the resource situation and the installed infrastructure on the Norwegian Continental Shelf. Then the potential of still maintaining a high activity level in field developments is outlined

Recognition and Management of Sleep-Disordered Breathing in Chronic Heart Failure

Science.gov (United States)

Kikta, Donald; Khayat, Rami

2013-01-01

It is increasingly recognized that sleep-disordered breathing (SDB) is a common modifiable risk factor for cardiovascular disease with significant impact on morbidity and potentially mortality. SDB is highly prevalent in patients with systolic or diastolic heart failure. A high index of suspicion is necessary to diagnose SDB in patients with heart failure because the vast majority of affected patients do not report daytime symptoms. Recent clinical trials have demonstrated improvement in heart function, exercise tolerance, and quality of life after treatment of SDB in patients with heart failure. Accumulating evidence suggests that treatment of SDB should complement the established pharmacologic therapy for chronic heart failure. However, mortality benefit has yet to be demonstrated. PMID:21086079

Congenital heart disease and chromossomopathies detected by the karyotype

Directory of Open Access Journals (Sweden)

Patrícia Trevisan

2014-06-01

Full Text Available OBJECTIVE: To review the relationship between congenital heart defects and chromosomal abnormalities detected by the karyotype.DATA SOURCES: Scientific articles were searched in MEDLINE database, using the descriptors "karyotype" OR "chromosomal" OR "chromosome" AND "heart defects, congenital". The research was limited to articles published in English from 1980 on.DATA SYNTHESIS: Congenital heart disease is characterized by an etiologically heterogeneous and not well understood group of lesions. Several researchers have evaluated the presence of chromosomal abnormalities detected by the karyotype in patients with congenital heart disease. However, most of the articles were retrospective studies developed in Europe and only some of the studied patients had a karyotype exam. In this review, only one study was conducted in Latin America, in Brazil. It is known that chromosomal abnormalities are frequent, being present in about one in every ten patients with congenital heart disease. Among the karyotype alterations in these patients, the most important is the trisomy 21 (Down syndrome. These patients often have associated extra-cardiac malformations, with a higher risk of morbidity and mortality, which makes heart surgery even more risky.CONCLUSIONS: Despite all the progress made in recent decades in the field of cytogenetic, the karyotype remains an essential tool in order to evaluate patients with congenital heart disease. The detailed dysmorphological physical examination is of great importance to indicate the need of a karyotype.

Congenital heart disease and chromossomopathies detected by the karyotype

Science.gov (United States)

Trevisan, Patrícia; Rosa, Rafael Fabiano M.; Koshiyama, Dayane Bohn; Zen, Tatiana Diehl; Paskulin, Giorgio Adriano; Zen, Paulo Ricardo G.

2014-01-01

OBJECTIVE: To review the relationship between congenital heart defects and chromosomal abnormalities detected by the karyotype. DATA SOURCES: Scientific articles were searched in MEDLINE database, using the descriptors "karyotype" OR "chromosomal" OR "chromosome" AND "heart defects, congenital". The research was limited to articles published in English from 1980 on. DATA SYNTHESIS: Congenital heart disease is characterized by an etiologically heterogeneous and not well understood group of lesions. Several researchers have evaluated the presence of chromosomal abnormalities detected by the karyotype in patients with congenital heart disease. However, most of the articles were retrospective studies developed in Europe and only some of the studied patients had a karyotype exam. In this review, only one study was conducted in Latin America, in Brazil. It is known that chromosomal abnormalities are frequent, being present in about one in every ten patients with congenital heart disease. Among the karyotype alterations in these patients, the most important is the trisomy 21 (Down syndrome). These patients often have associated extra-cardiac malformations, with a higher risk of morbidity and mortality, which makes heart surgery even more risky. CONCLUSIONS: Despite all the progress made in recent decades in the field of cytogenetic, the karyotype remains an essential tool in order to evaluate patients with congenital heart disease. The detailed dysmorphological physical examination is of great importance to indicate the need of a karyotype. PMID:25119760

Report of the American Heart Association (AHA) Scientific Sessions 2012, Los Angeles.

Science.gov (United States)

Fujita, Jun

2013-01-01

The American Heart Association (AHA) Scientific Sessions were held for the first time in Los Angeles in 2012, with the most up-to-date basic and clinical science in the field presented and heard by physicians, research scientists, students, and paramedical personnel from 100 countries. Japan accounted for the second highest number of submitted abstracts and the Japanese Circulation Society actively contributed to the success of the AHA Scientific Sessions this year. The Late-Breaking Clinical Trial sessions comprised 27 clinical studies presented in the main hall. The FREEDOM study revealed the superiority of using a coronary artery bypass graft for diabetic multivessel coronary artery diseases over percutaneous coronary intervention using a drug-eluting stent. A new peptide hormone, serelaxin, improved dyspnea in heart failure patients and significantly reduced mortality rates according to the RELAX-AHF study. In the basic sciences, primary necrosis in mitochondria was the hot topic, while genetics, including genome-wide association studies, and epigenetics were strong features of the basic and clinical cardiovascular (CV) science. It was also clear that regenerative medicine is now part of mainstream CV research, with several clinical trials underway and many basic research projects ongoing around the world. Induced pluripotent stem cells in particular have the potential to change CV medicine, and will underpin the next era of regenerative medicine and personal therapies for heart diseases.

Smart pillow for heart-rate monitoring using a fiber optic sensor

Science.gov (United States)

Chen, Zhihao; Teo, Ju Teng; Ng, Soon Huat; Yim, Huiqing

2011-03-01

In this paper, we propose and demonstrate a new method to monitor heart rate using fiber optic microbending based sensor for in-bed non-intrusive monitoring. The sensing system consists of transmitter, receiver, sensor mat, National Instrument (NI) data acquisition (DAQ) card and a computer for signal processing. The sensor mat is embedded inside a commercial pillow. The heart rate measurement system shows an accuracy of +/-2 beats, which has been successfully demonstrated in a field trial. The key technological advantage of our system is its ability to measure heart rate with no preparation and minimal compliance by the patient.

Nonlinear analysis of heart rate variability in patients with eating disorders

NARCIS (Netherlands)

Vigo, Daniel E.; Castro, Mariana N.; Dorpinghaus, Andrea; Weidema, Hylke; Cardinali, Daniel P.; Siri, Leonardo Nicola; Rovira, Bernardo; Fahrer, Rodolfo D.; Nogues, Martin; Leiguarda, Ramon C.; Guinjoan, Salvador M.

2008-01-01

Patients with anorexia nervosa or bulimia nervosa often have signs of autonomic dysfunction potentially deleterious to the heart. The aim of this study was to ascertain the nonlinear properties of heart rate variability in patients with eating disorders. A group of 33 women with eating disorders (14

Stability Analysis and Variational Integrator for Real-Time Formation Based on Potential Field

Directory of Open Access Journals (Sweden)

Shengqing Yang

2014-01-01

Full Text Available This paper investigates a framework of real-time formation of autonomous vehicles by using potential field and variational integrator. Real-time formation requires vehicles to have coordinated motion and efficient computation. Interactions described by potential field can meet the former requirement which results in a nonlinear system. Stability analysis of such nonlinear system is difficult. Our methodology of stability analysis is discussed in error dynamic system. Transformation of coordinates from inertial frame to body frame can help the stability analysis focus on the structure instead of particular coordinates. Then, the Jacobian of reduced system can be calculated. It can be proved that the formation is stable at the equilibrium point of error dynamic system with the effect of damping force. For consideration of calculation, variational integrator is introduced. It is equivalent to solving algebraic equations. Forced Euler-Lagrange equation in discrete expression is used to construct a forced variational integrator for vehicles in potential field and obstacle environment. By applying forced variational integrator on computation of vehicles' motion, real-time formation of vehicles in obstacle environment can be implemented. Algorithm based on forced variational integrator is designed for a leader-follower formation.

Overview of American Heart Association / American College of Cardiology guidelines 2017 for management of patients with valvular heart disease

Directory of Open Access Journals (Sweden)

M.Т. Vatutin

2017-12-01

Full Text Available n June 2017, Circulation journal published updated recommendations of the American Heart Association and the American College of Cardiology (AHA / ACC on the management of patients with valvular heart disease. The main provisions of this manual are set out in this message. It should be emphasized that the recommendations written by leading US experts in this field are set out clearly, using a variety of tables and figures, which will undoubtedly make them a desktop guide to action for most practitioners in the following years. As usual, when creating such guidelines, the authors were guided by evidence-based methodology using the classes of recommendations and levels of evidence.

Therapeutic potential of functional selectivity in the treatment of heart failure

DEFF Research Database (Denmark)

Christensen, Gitte Lund; Aplin, Mark; Hansen, Jakob Lerche

2010-01-01

Adrenergic and angiotensin receptors are prominent targets in pharmacological alleviation of cardiac remodeling and heart failure, but their use is associated with cardiodepressant side effects. Recent advances in our understanding of seven transmembrane receptor signaling show that it is possible...... to design ligands with "functional selectivity," acting as agonists on certain signaling pathways while antagonizing others. This represents a major pharmaceutical opportunity to separate desired from adverse effects governed by the same receptor. Accordingly, functionally selective ligands are currently...

Cross-field flow and electric potential in a plasma slab

Directory of Open Access Journals (Sweden)

J. De Keyser

2013-08-01

Full Text Available We consider cross-field plasma flow inside a field-aligned plasma slab embedded in a uniform background in a 1-dimensional geometry. This situation may arise, for instance, when long-lasting reconnection pulses inject plasma into the inner magnetosphere. The present paper presents a detailed analysis of the structure of the interfaces that separate the slab from the background plasma on either side; a fully kinetic model is used to do so. Since the velocity shear across both interfaces has opposite signs, and given the typical gyroradius differences between injected and background ions and electrons, the structure of both interfaces can be very different. The behaviour of the slab and its interfaces depends critically on the flow of the plasma transverse to the magnetic field; in particular, it is shown that there are bounds to the flow speed that can be supported by the magnetised plasma. Further complicating the picture is the effect of the potential difference between the slab and its environment.

Effective field theory approaches for tensor potentials

Energy Technology Data Exchange (ETDEWEB)

Jansen, Maximilian

2016-11-14

Effective field theories are a widely used tool to study physical systems at low energies. We apply them to systematically analyze two and three particles interacting via tensor potentials. Two examples are addressed: pion interactions for anti D{sup 0}D{sup *0} scattering to dynamically generate the X(3872) and dipole interactions for two and three bosons at low energies. For the former, the one-pion exchange and for the latter, the long-range dipole force induce a tensor-like structure of the potential. We apply perturbative as well as non-perturbative methods to determine low-energy observables. The X(3872) is of major interest in modern high-energy physics. Its exotic characteristics require approaches outside the range of the quark model for baryons and mesons. Effective field theories represent such methods and provide access to its peculiar nature. We interpret the X(3872) as a hadronic molecule consisting of neutral D and D{sup *} mesons. It is possible to apply an effective field theory with perturbative pions. Within this framework, we address chiral as well as finite volume extrapolations for low-energy observables, such as the binding energy and the scattering length. We show that the two-point correlation function for the D{sup *0} meson has to be resummed to cure infrared divergences. Moreover, next-to-leading order coupling constants, which were introduced by power counting arguments, appear to be essential to renormalize the scattering amplitude. The binding energy as well as the scattering length display a moderate dependence on the light quark masses. The X(3872) is most likely deeper bound for large light quark masses. In a finite volume on the other hand, the binding energy significantly increases. The dependence on the light quark masses and the volume size can be simultaneously obtained. For bosonic dipoles we apply a non-perturbative, numerical approach. We solve the Lippmann-Schwinger equation for the two-dipole system and the Faddeev

Behaviour Problems in Children with Congenital Heart Disease

Directory of Open Access Journals (Sweden)

Beena Johnson

2015-01-01

Full Text Available As more children survive with congenital heart diseases, management of their behavioural problems are becoming increasingly important. In this article we aim to review the current status of knowledge on this aspect. Children with congenital heart diseases have more behavioural problems compared to children without chronic illnesses. Behavioural problems in children can be classified into externalizing behaviours and internalizing behaviours. Externalizing behaviours are marked by defiance, impulsivity, hyperactivity, disruptiveness, aggression and antisocial features. Internalizing behaviours are evidenced by withdrawal, dysphoria and anxiety. Boys with congenital heart diseases have more externalizing problems compared to girls. Preoperative hypoxia as well as peri and postoperative cardiocirculatory insufficiency can lead to internalizing and externalizing behavioral problems in future. High treatment intensity and palliative interventions are associated with poor behavioral outcomes. Children who underwent open heart surgery at very young age are prone to develop attention-deficit hyperactivity disorder on reaching school age. A comprehensive approach in this field is essential, so that effective early interventions and guidance can be planned.

Decellularized allogeneic heart valves demonstrate self-regeneration potential after a long-term preclinical evaluation.

Directory of Open Access Journals (Sweden)

Laura Iop

Full Text Available Tissue-engineered heart valves are proposed as novel viable replacements granting longer durability and growth potential. However, they require extensive in vitro cell-conditioning in bioreactor before implantation. Here, the propensity of non-preconditioned decellularized heart valves to spontaneous in body self-regeneration was investigated in a large animal model. Decellularized porcine aortic valves were evaluated for right ventricular outflow tract (RVOT reconstruction in Vietnamese Pigs (n = 11 with 6 (n = 5 and 15 (n = 6 follow-up months. Repositioned native valves (n = 2 for each time were considered as control. Tissue and cell components from explanted valves were investigated by histology, immunohistochemistry, electron microscopy, and gene expression. Most substitutes constantly demonstrated in vivo adequate hemodynamic performances and ex vivo progressive repopulation during the 15 implantation months without signs of calcifications, fibrosis and/or thrombosis, as revealed by histological, immunohistochemical, ultrastructural, metabolic and transcriptomic profiles. Colonizing cells displayed native-like phenotypes and actively synthesized novel extracellular matrix elements, as collagen and elastin fibers. New mature blood vessels, i.e. capillaries and vasa vasorum, were identified in repopulated valves especially in the medial and adventitial tunicae of regenerated arterial walls. Such findings correlated to the up-regulated vascular gene transcription. Neoinnervation hallmarks were appreciated at histological and ultrastructural levels. Macrophage populations with reparative M2 phenotype were highly represented in repopulated valves. Indeed, no aspects of adverse/immune reaction were revealed in immunohistochemical and transcriptomic patterns. Among differentiated elements, several cells were identified expressing typical stem cell markers of embryonic, hematopoietic, neural and mesenchymal lineages in significantly

On radiation of electrons moving in braking electric fields with distributed potential

International Nuclear Information System (INIS)

Fedulov, V.I.; Suvorov, V.I.; Umirov, U.R.

2002-01-01

The characteristics of radiation of electron moving in flat structures with braking electric field created by an accelerating electrode and another electrode with distributed potential are investigated. The analytical expressions for definition of conditions for complete loss of energy by electron in structure with distributed potential and for arising the electron vibrations are received. Also expressions connecting the electron energy with the point of entry and its fluctuation frequency are received. The mathematical model of irradiation process is offered depending on energy and point of entry of the electron. The connection between a radiation wave length and position of point of entry of electrons in the braking electric field are found. A possibility of emerging the optical radiation in solid environments at passage of charge particles through substance is shown. (author)

Simple, heart-smart substitutions

Science.gov (United States)

Coronary artery disease - heart smart substitutions; Atherosclerosis - heart smart substitutions; Cholesterol - heart smart substitutions; Coronary heart disease - heart smart substitutions; Healthy diet - heart ...

Uncertainties in estimating heart doses from 2D-tangential breast cancer radiotherapy

DEFF Research Database (Denmark)

Laugaard Lorenzen, Ebbe; Brink, Carsten; Taylor, Carolyn W.

2016-01-01

BACKGROUND AND PURPOSE: We evaluated the accuracy of three methods of estimating radiation dose to the heart from two-dimensional tangential radiotherapy for breast cancer, as used in Denmark during 1982-2002. MATERIAL AND METHODS: Three tangential radiotherapy regimens were reconstructed using CT......-based planning scans for 40 patients with left-sided and 10 with right-sided breast cancer. Setup errors and organ motion were simulated using estimated uncertainties. For left-sided patients, mean heart dose was related to maximum heart distance in the medial field. RESULTS: For left-sided breast cancer, mean...... to the uncertainty of estimates based on individual CT-scans. For right-sided breast cancer patients, mean heart dose based on individual CT-scans was always

Coronary heart disease

Science.gov (United States)

Heart disease, Coronary heart disease, Coronary artery disease; Arteriosclerotic heart disease; CHD; CAD ... buildup of plaque in the arteries to your heart. This may also be called hardening of the ...

Augmentation of Creatine in the Heart.

Science.gov (United States)

Zervou, Sevasti; Whittington, Hannah J; Russell, Angela J; Lygate, Craig A

2016-01-01

Creatine is a principle component of the creatine kinase (CK) phosphagen system common to all vertebrates. It is found in excitable cells, such as cardiomyocytes, where it plays an important role in the buffering and transport of chemical energy to ensure that supply meets the dynamic demands of the heart. Multiple components of the CK system, including intracellular creatine levels, are reduced in heart failure, while ischaemia and hypoxia represent acute crises of energy provision. Elevation of myocardial creatine levels has therefore been suggested as potentially beneficial, however, achieving this goal is not trivial. This mini-review outlines the evidence in support of creatine elevation and critically examines the pharmacological approaches that are currently available. In particular, dietary creatine-supplementation does not sufficiently elevate creatine levels in the heart due to subsequent down-regulation of the plasma membrane creatine transporter (CrT). Attempts to increase passive diffusion and bypass the CrT, e.g. via creatine esters, have yet to be tested in the heart. However, studies in mice with genetic overexpression of the CrT demonstrate proof-of-principle that elevated creatine protects the heart from ischaemia-reperfusion injury. This suggests activation of the CrT as a major unmet pharmacological target. However, translation of this finding to the clinic will require a greater understanding of CrT regulation in health and disease and the development of small molecule activators.

Combination stem cell therapy for heart failure

Directory of Open Access Journals (Sweden)

Ichim Thomas E

2010-04-01

Full Text Available Abstract Patients with congestive heart failure (CHF that are not eligible for transplantation have limited therapeutic options. Stem cell therapy such as autologous bone marrow, mobilized peripheral blood, or purified cells thereof has been used clinically since 2001. To date over 1000 patients have received cellular therapy as part of randomized trials, with the general consensus being that a moderate but statistically significant benefit occurs. Therefore, one of the important next steps in the field is optimization. In this paper we discuss three ways to approach this issue: a increasing stem cell migration to the heart; b augmenting stem cell activity; and c combining existing stem cell therapies to recapitulate a "therapeutic niche". We conclude by describing a case report of a heart failure patient treated with a combination stem cell protocol in an attempt to augment beneficial aspects of cord blood CD34 cells and mesenchymal-like stem cells.

Magnetophoretic potential at the movement of cluster products of electrochemical reactions in an inhomogeneous magnetic field

International Nuclear Information System (INIS)

Gorobets, O. Yu.; Gorobets, Yu. I.; Rospotniuk, V. P.

2015-01-01

An electric field arises from the influence of a nonuniform static magnetic field on charged colloid particles with magnetic susceptibility different from that of the surrounding liquid. It arises, for example, under the influence of a nonuniform static magnetic field in clusters of electrochemical reaction products created during metal etching, deposition, and corrosion processes without an external electric current passing through an electrolyte near a magnetized electrode surface. The corresponding potential consists of a Nernst potential of inhomogeneous distribution of concentration of colloid particles and a magnetophoretic potential (MPP). This potential has been calculated using a thermodynamic approach based on the equations of thermodynamics of nonequilibrium systems and the Onsager relations for a mass flow of correlated magnetic clusters under a gradient magnetic force in the electrolyte. The conditions under which the MPP contribution to the total electric potential may be significant are discussed with a reference to the example of a corroding spherical ferromagnetic steel electrode

Magnetophoretic potential at the movement of cluster products of electrochemical reactions in an inhomogeneous magnetic field

Energy Technology Data Exchange (ETDEWEB)

Gorobets, O. Yu., E-mail: pitbm@ukr.net; Gorobets, Yu. I., E-mail: Gorobets@imag.kiev.ua [National Technical University of Ukraine “KPI”, Peremogy Avenue 37, Kyiv 03056 (Ukraine); Institute of Magnetism NAS of Ukraine and National Academy of Sciences of Ukraine, Vernadsky Avenue, 36-b, Kyiv 03142 (Ukraine); Rospotniuk, V. P. [National Technical University of Ukraine “KPI”, Peremogy Avenue 37, Kyiv 03056 (Ukraine)

2015-08-21

An electric field arises from the influence of a nonuniform static magnetic field on charged colloid particles with magnetic susceptibility different from that of the surrounding liquid. It arises, for example, under the influence of a nonuniform static magnetic field in clusters of electrochemical reaction products created during metal etching, deposition, and corrosion processes without an external electric current passing through an electrolyte near a magnetized electrode surface. The corresponding potential consists of a Nernst potential of inhomogeneous distribution of concentration of colloid particles and a magnetophoretic potential (MPP). This potential has been calculated using a thermodynamic approach based on the equations of thermodynamics of nonequilibrium systems and the Onsager relations for a mass flow of correlated magnetic clusters under a gradient magnetic force in the electrolyte. The conditions under which the MPP contribution to the total electric potential may be significant are discussed with a reference to the example of a corroding spherical ferromagnetic steel electrode.

Preattentive processing of heart cues and the perception of heart symptoms in congenital heart disease

NARCIS (Netherlands)

Karsdorp, Petra A.; Kindt, Merel; Everaerd, Walter; Mulder, Barbara J. M.

2007-01-01

The present study was aimed at clarifying whether preattentive processing of heart cues results in biased perception of heart sensations in patients with congenital heart disease (ConHD) who are also highly trait anxious. Twenty-six patients with ConHD and 22 healthy participants categorized

The use of simple indicators for detecting potential coronary heart disease susceptibility in the third-class airman population.

Science.gov (United States)

1972-07-01

An analysis was made of an eight-year interval change in several Framingham Heart Study (FHS) indicators of coronary heart disease (CHD) susceptibility as measured on 475 male air traffic control (ATC) personnel. The initial measurements were obtaine...

Discussion on prospecting potential for rich uranium deposits in Xiazhuang uranium ore-field, northern Guangdong

International Nuclear Information System (INIS)

Wu Lieqin; Tan Zhengzhong

2004-01-01

Based on analyzing the prospecting potential for uranium deposits in Xiazhuang uranium ore field this paper discusses the prospecting for rich uranium deposits and prospecting potential in the region. Research achievements indicate: that the Xiazhuang ore-field is an ore-concentrated area where uranium has been highly enriched, and possesses good prospecting potential and perspective, becoming one of the most important prospecting areas for locating rich uranium deposits in northern Guangdong; that the 'intersection type', the alkaline metasomatic fractured rock type and the vein-group type uranium deposits are main targets and the prospecting direction for future uranium prospecting in this region

Stable Flocking of Multiple Agents Based on Molecular Potential Field and Distributed Receding Horizon Control

International Nuclear Information System (INIS)

Zhang Yun-Peng; Duan Hai-Bin; Zhang Xiang-Yin

2011-01-01

A novel distributed control scheme to generate stable flocking motion for a group of agents is proposed. In this control scheme, a molecular potential field model is applied as the potential field function because of its smoothness and unique shape. The approach of distributed receding horizon control is adopted to drive each agent to find its optimal control input to lower its potential at every step. Experimental results show that this proposed control scheme can ensure that all agents eventually converge to a stable flocking formation with a common velocity and the collisions can also be avoided at the same time. (general)

A short proof that the Coulomb-gauge potentials yield the retarded fields

Energy Technology Data Exchange (ETDEWEB)

Heras, Jose A, E-mail: herasgomez@gmail.co [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Av. San Pablo No. 180, Col. Reynosa, Mexico D. F. 02200 (Mexico)

2011-01-15

A short demonstration that the potentials in the Coulomb gauge yield the retarded electric and magnetic fields is presented. This demonstration is relatively simple and can be presented in an advanced undergraduate course of electromagnetic theory.

A short proof that the Coulomb-gauge potentials yield the retarded fields

International Nuclear Information System (INIS)

Heras, Jose A

2011-01-01

A short demonstration that the potentials in the Coulomb gauge yield the retarded electric and magnetic fields is presented. This demonstration is relatively simple and can be presented in an advanced undergraduate course of electromagnetic theory.

Expression of hLAMP-1-Positive Particles During Early Heart Development in the Chick.

Science.gov (United States)

Abd-Elhamid, T H; Conway, M L; Sinning, A R

2017-10-01

Heart development requires coordinated activity of various factors, the disturbance of which can lead to congenital heart defects. Heart lectin-associated matrix protein-1 (hLAMP-1) is a matrix protein expressed within Hensen's node at Hamburger-Hamilton (HH) stage 4, in the lateral mesoderm by HH stages 5-6 and enhanced within the left pre-cardiac field at HH stage 7. At HH stages 15-16, hLAMP-1 expression is observed in the atrioventricular canal and the outflow tract. Also, the role of hLAMP-1 in induction of mesenchyme formation in chick heart has been well documented. To further elucidate the role of this molecule in heart development, we examined its expression patterns during HH stages 8-14 in the chick. In this regard, we immunostained sections of the heart during HH stages 8-14 with antibodies specific to hLAMP-1. Our results showed prominent expression of hLAMP-1-positive particles in the extracellular matrix associated with the pre-cardiac mesoderm, the endoderm, ectoderm as well as neuroectoderm at HH stages 8-9. After formation of the linear heart tube at HH stage 10, the expression of hLAMP-1-stained particles disappears in those regions of original contact between the endoderm and heart forming fields due to rupture of the dorsal mesocardium while their expression becomes confined to the arterial and venous poles of the heart tube. This expression pattern is maintained until HH stage 14. This expression pattern suggests that hLAMP-1 may be involved in the formation of the endocardial tube. © 2017 Blackwell Verlag GmbH.

Radiation dose to the heart in paediatric interventional cardiology

International Nuclear Information System (INIS)

Keiller, D A; Martin, C J

2015-01-01

Recent ICRP publications have reviewed evidence for induction of heart disease. Studies suggest the threshold dose to the heart may be as low as 500 mGy. Doses to the heart from paediatric interventional procedures performed in Glasgow between April 2012 and July 2013 to correct congenital heart defects were investigated to assess the level of potential risk of cardiovascular disease. For common procedures, doses were found to be typically less than 50 mGy, with the highest dose in the period for which data are available estimated to be 330 mGy. These results suggest that any increased risk due to paediatric interventional cardiology is likely to be small, but cumulative doses over a number of years could reach the threshold for effects. (paper)

Expression and function of Ccbe1 in the chick early cardiogenic regions are required for correct heart development.

Directory of Open Access Journals (Sweden)

João Furtado

Full Text Available During the course of a differential screen to identify transcripts specific for chick heart/hemangioblast precursor cells, we have identified Ccbe1 (Collagen and calcium-binding EGF-like domain 1. While the importance of Ccbe1 for the development of the lymphatic system is now well demonstrated, its role in cardiac formation remained unknown. Here we show by whole-mount in situ hybridization analysis that cCcbe1 mRNA is initially detected in early cardiac progenitors of the two bilateral cardiogenic fields (HH4, and at later stages on the second heart field (HH9-18. Furthermore, cCcbe1 is expressed in multipotent and highly proliferative cardiac progenitors. We characterized the role of cCcbe1 during early cardiogenesis by performing functional studies. Upon morpholino-induced cCcbe1 knockdown, the chick embryos displayed heart malformations, which include aberrant fusion of the heart fields, leading to incomplete terminal differentiation of the cardiomyocytes. cCcbe1 overexpression also resulted in severe heart defects, including cardia bifida. Altogether, our data demonstrate that although cardiac progenitors cells are specified in cCcbe1 morphants, the migration and proliferation of cardiac precursors cells are impaired, suggesting that cCcbe1 is a key gene during early heart development.

Immunostaining of dissected zebrafish embryonic heart.

Science.gov (United States)

Yang, Jingchun; Xu, Xiaolei

2012-01-10

Zebrafish embryo becomes a popular in vivo vertebrate model for studying cardiac development and human heart diseases due to its advantageous embryology and genetics. About 100-200 embryos are readily available every week from a single pair of adult fish. The transparent embryos that develop ex utero make them ideal for assessing cardiac defects. The expression of any gene can be manipulated via morpholino technology or RNA injection. Moreover, forward genetic screens have already generated a list of mutants that affect different perspectives of cardiogenesis. Whole mount immunostaining is an important technique in this animal model to reveal the expression pattern of the targeted protein to a particular tissue. However, high resolution images that can reveal cellular or subcellular structures have been difficult, mainly due to the physical location of the heart and the poor penetration of the antibodies. Here, we present a method to address these bottlenecks by dissecting heart first and then conducting the staining process on the surface of a microscope slide. To prevent the loss of small heart samples and to facilitate solution handling, we restricted the heart samples within a circle on the surface of the microscope slides drawn by an immEdge pen. After the staining, the fluorescence signals can be directly observed by a compound microscope. Our new method significantly improves the penetration for antibodies, since a heart from an embryonic fish only consists of few cell layers. High quality images from intact hearts can be obtained within a much reduced procession time for zebrafish embryos aged from day 2 to day 6. Our method can be potentially extended to stain other organs dissected from either zebrafish or other small animals. Copyright © 2012 Journal of Visualized Experiments

HEART OF MYTH – HEART OF SCIENCE Part I

Science.gov (United States)

Bound Alberti, Fay

2015-01-01

This article explores the history and meanings of the heart and its diseases as aspects of the histories of science and emotion. Analyzing the twofold meanings of the heart as both bodily object and cultural symbol, it explores the reasons for the apparent conflict in meanings of the heart of science and the heart of emotion in Western medical culture since the 19th century. In Part I, a case study of the writer, economist, and philosopher Harriet Martineau is used to demonstrate and trace that conflict, while Part II highlights the manifold meanings of the heart both in the past and in the present. PMID:26167117

Improved ring potential of QED at finite temperature and in the presence of weak and strong magnetic fields

International Nuclear Information System (INIS)

Sadooghi, N.; Anaraki, K. Sohrabi

2008-01-01

Using the general structure of the vacuum polarization tensor Π μν (k 0 ,k) in the infrared (IR) limit, k 0 →0, the ring contribution to the QED effective potential at finite temperature and the nonzero magnetic field is determined beyond the static limit, (k 0 →0, k→0). The resulting ring potential is then studied in weak and strong magnetic field limits. In the weak magnetic field limit, at high temperature and for α→0, the improved ring potential consists of a term proportional to T 4 α 5/2 , in addition to the expected T 4 α 3/2 term arising from the static limit. Here, α is the fine structure constant. In the limit of the strong magnetic field, where QED dynamics is dominated by the lowest Landau level, the ring potential includes a novel term consisting of dilogarithmic function (eB)Li 2 (-(2α/π)(eB/m 2 )). Using the ring improved (one-loop) effective potential including the one-loop effective potential and ring potential in the IR limit, the dynamical chiral symmetry breaking of QED is studied at finite temperature and in the presence of the strong magnetic field. The gap equation, the dynamical mass and the critical temperature of QED in the regime of the lowest Landau level dominance are determined in the improved IR as well as in the static limit. For a given value of the magnetic field, the improved ring potential is shown to be more efficient in decreasing the critical temperature arising from the one-loop effective potential.

Surface potential at a ferroelectric grain due to asymmetric screening of depolarization fields

Energy Technology Data Exchange (ETDEWEB)

Genenko, Yuri A., E-mail: genenko@mm.tu-darmstadt.de; Hirsch, Ofer [Technische Universität Darmstadt, Darmstadt (Germany); Erhart, Paul [Chalmers University of Technology, Gothenburg (Sweden)

2014-03-14

Nonlinear screening of electric depolarization fields, generated by a stripe domain structure in a ferroelectric grain of a polycrystalline material, is studied within a semiconductor model of ferroelectrics. It is shown that the maximum strength of local depolarization fields is rather determined by the electronic band gap than by the spontaneous polarization magnitude. Furthermore, field screening due to electronic band bending and due to presence of intrinsic defects leads to asymmetric space charge regions near the grain boundary, which produce an effective dipole layer at the surface of the grain. This results in the formation of a potential difference between the grain surface and its interior of the order of 1 V, which can be of either sign depending on defect transition levels and concentrations. Exemplary acceptor doping of BaTiO{sub 3} is shown to allow tuning of the said surface potential in the region between 0.1 and 1.3 V.

Women and Heart Disease: Sharing Advice from the Heart

Science.gov (United States)

... page please turn JavaScript on. Feature: Women and Heart Disease Sharing Advice From The Heart Past Issues / Spring 2016 Table of Contents This ... inspired you to get involved in the American Heart Association's Go Red For Women movement and Red ...

Advanced Heart Failure

Science.gov (United States)

... Artery Disease Venous Thromboembolism Aortic Aneurysm More Advanced Heart Failure Updated:May 9,2017 When heart failure (HF) ... Making This content was last reviewed May 2017. Heart Failure • Home • About Heart Failure • Causes and Risks for ...

Types of Heart Failure

Science.gov (United States)

... Introduction Types of Heart Failure Classes of Heart Failure Heart Failure in Children Advanced Heart Failure • Causes and ... and procedures related to heart disease and stroke. Heart Failure Questions to Ask Your Doctor Use these questions ...

Internal and external potential-field estimation from regional vector data at varying satellite altitude

Science.gov (United States)

Plattner, Alain; Simons, Frederik J.

2017-10-01

When modelling satellite data to recover a global planetary magnetic or gravitational potential field, the method of choice remains their analysis in terms of spherical harmonics. When only regional data are available, or when data quality varies strongly with geographic location, the inversion problem becomes severely ill-posed. In those cases, adopting explicitly local methods is to be preferred over adapting global ones (e.g. by regularization). Here, we develop the theory behind a procedure to invert for planetary potential fields from vector observations collected within a spatially bounded region at varying satellite altitude. Our method relies on the construction of spatiospectrally localized bases of functions that mitigate the noise amplification caused by downward continuation (from the satellite altitude to the source) while balancing the conflicting demands for spatial concentration and spectral limitation. The `altitude-cognizant' gradient vector Slepian functions (AC-GVSF) enjoy a noise tolerance under downward continuation that is much improved relative to the `classical' gradient vector Slepian functions (CL-GVSF), which do not factor satellite altitude into their construction. Furthermore, venturing beyond the realm of their first application, published in a preceding paper, in the present article we extend the theory to being able to handle both internal and external potential-field estimation. Solving simultaneously for internal and external fields under the limitation of regional data availability reduces internal-field artefacts introduced by downward-continuing unmodelled external fields, as we show with numerical examples. We explain our solution strategies on the basis of analytic expressions for the behaviour of the estimation bias and variance of models for which signal and noise are uncorrelated, (essentially) space- and band-limited, and spectrally (almost) white. The AC-GVSF are optimal linear combinations of vector spherical harmonics

Effects on functional groups and zeta potential of SAP1pulsed electric field technology.

Science.gov (United States)

Liang, Rong; Li, Xuenan; Lin, Songyi; Wang, Jia

2017-01-01

SAP 1 pulsed electric field (PEF) technology. The effects of electric field intensity and pulse frequency on SAP 1 electric field intensity 15 kV cm -1 , pulse frequency 1600 Hz and flow velocity 2.93 mL min -1 ). Furthermore, the PEF-treated SAP 1 < MW < 3kDa under optimal conditions lacked the characteristic absorbance of N-H, C = C and the amide band and the zeta potential was reduced to -18.0 mV. Overall, the results of the present study suggest that the improvement of antioxidant activity of SAP 1 < MW < 3kDa is a result of the contribution of the functional groups and the change in zeta potential when treated with PEF. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

The evolving role of the total artificial heart in the management of end-stage congenital heart disease and adolescents.

Science.gov (United States)

Ryan, Thomas D; Jefferies, John L; Zafar, Farhan; Lorts, Angela; Morales, David L S

2015-01-01

Advances in medical therapies have yielded improvement in morbidity and a decrease in mortality for patients with congenital heart disease, both surgically palliated and uncorrected. An unintended consequence is a cohort of adolescent and adult patients with heart failure who require alternative therapies. One intriguing option is placement of a total artificial heart (TAH) either as a bridge to transplant or as a destination therapy. Of the 1091 Jarvik-7 type TAH (Symbion, CardioWest and SynCardia) placed between 1985 and 2012, only 24 have been performed in patients with congenital heart disease, and a total of 51 were placed in patients younger than 21. At our institution, the SynCardia TAH was implanted in a 19-year-old patient with cardiac allograft failure because of chronic rejection and related multisystem organ failure including need for hemodialysis. Over the next year, she was nutritionally and physically rehabilitated, as were her end organs, allowing her to come off dialysis, achieve normal renal function and eventually be successfully transplanted. Given the continued growth of adolescent and adult congenital heart disease populations with end-stage heart failure, the TAH may offer therapeutic options where previously there were few. In addition, smaller devices such as the SynCardia 50/50 will open the door for applications in smaller children. The Freedom Driver offers the chance for patients to leave the hospital with a TAH, as does the AbioCor, which is a fully implantable TAH option. In this report, we review the history of the TAH and potential applications in adolescent patients and congenital heart disease.

Thyroid hormone action in postnatal heart development

Directory of Open Access Journals (Sweden)

Ming Li

2014-11-01

Full Text Available Thyroid hormone is a critical regulator of cardiac growth and development, both in fetal life and postnatally. Here we review the role of thyroid hormone in postnatal cardiac development, given recent insights into its role in stimulating a burst of cardiomyocyte proliferation in the murine heart in preadolescence; a response required to meet the massive increase in circulatory demand predicated by an almost quadrupling of body weight during a period of about 21 days from birth to adolescence. Importantly, thyroid hormone metabolism is altered by chronic diseases, such as heart failure and ischemic heart disease, as well as in very sick children requiring surgery for congenital heart diseases, which results in low T3 syndrome that impairs cardiovascular function and is associated with a poor prognosis. Therapy with T3 or thyroid hormone analogs has been shown to improve cardiac contractility; however, the mechanism is as yet unknown. Given the postnatal cardiomyocyte mitogenic potential of T3, its ability to enhance cardiac function by promoting cardiomyocyte proliferation warrants further consideration.

Fuzzy Expert System for Heart Attack Diagnosis

Science.gov (United States)

Hassan, Norlida; Arbaiy, Nureize; Shah, Noor Aziyan Ahmad; Afizah Afif@Afip, Zehan

2017-08-01

Heart attack is one of the serious illnesses and reported as the main killer disease. Early prevention is significant to reduce the risk of having the disease. The prevention efforts can be strengthen through awareness and education about risk factor and healthy lifestyle. Therefore the knowledge dissemination is needed to play role in order to distribute and educate public in health care management and disease prevention. Since the knowledge dissemination in medical is important, there is a need to develop a knowledge based system that can emulate human intelligence to assist decision making process. Thereby, this study utilized hybrid artificial intelligence (AI) techniques to develop a Fuzzy Expert System for Diagnosing Heart Attack Disease (HAD). This system integrates fuzzy logic with expert system, which helps the medical practitioner and people to predict the risk and as well as diagnosing heart attack based on given symptom. The development of HAD is expected not only providing expert knowledge but potentially become one of learning resources to help citizens to develop awareness about heart-healthy lifestyle.

Diuretics for heart failure.

Science.gov (United States)

Faris, Rajaa F; Flather, Marcus; Purcell, Henry; Poole-Wilson, Philip A; Coats, Andrew J S

2012-02-15

Chronic heart failure is a major cause of morbidity and mortality worldwide. Diuretics are regarded as the first-line treatment for patients with congestive heart failure since they provide symptomatic relief. The effects of diuretics on disease progression and survival remain unclear. To assess the harms and benefits of diuretics for chronic heart failure Updated searches were run in the Cochrane Central Register of Controlled Trials in The Cochrane Library (CENTRAL Issue 1 of 4, 2011), MEDLINE (1966 to 22 February 2011), EMBASE (1980 to 2011 Week 07) and HERDIN database (1990 to February 2011). We hand searched pertinent journals and reference lists of papers were inspected. We also contacted manufacturers and researchers in the field. No language restrictions were applied. Double-blinded randomised controlled trials of diuretic therapy comparing one diuretic with placebo, or one diuretic with another active agent (e.g. ACE inhibitors, digoxin) in patients with chronic heart failure. Two authors independently abstracted the data and assessed the eligibility and methodological quality of each trial. Extracted data were analysed by determining the odds ratio for dichotomous data, and difference in means for continuous data, of the treated group compared with controls. The likelihood of heterogeneity of the study population was assessed by the Chi-square test. If there was no evidence of statistical heterogeneity and pooling of results was clinically appropriate, a combined estimate was obtained using the fixed-effects model. This update has not identified any new studies for inclusion. The review includes 14 trials (525 participants), 7 were placebo-controlled, and 7 compared diuretics against other agents such as ACE inhibitors or digoxin. We analysed the data for mortality and for worsening heart failure. Mortality data were available in 3 of the placebo-controlled trials (202 participants). Mortality was lower for participants treated with diuretics than for

Interaction potentials for multiquark states from instantons and other background gauge field configurations

International Nuclear Information System (INIS)

Warner, R.C.; Joshi, G.C.

1979-01-01

A simple rule is presented for calculating the contributions to the interaction potentials between constituent particles for a family of multiquark states, due to the presence of a semi-classical gauge field configuration which exists in a single SU(2) subgroup of colour SU(3). In multiquark states beyond the baryon many-body potential terms are found. The static (Wilson loop) limit is sufficient to elucidate the dependence of the potential on the colour structure of the multiquark state

Histone methylations in heart development, congenital and adult heart diseases.

Science.gov (United States)

Zhang, Qing-Jun; Liu, Zhi-Ping

2015-01-01

Heart development comprises myocyte specification, differentiation and cardiac morphogenesis. These processes are regulated by a group of core cardiac transcription factors in a coordinated temporal and spatial manner. Histone methylation is an emerging epigenetic mechanism for regulating gene transcription. Interplay among cardiac transcription factors and histone lysine modifiers plays important role in heart development. Aberrant expression and mutation of the histone lysine modifiers during development and in adult life can cause either embryonic lethality or congenital heart diseases, and influences the response of adult hearts to pathological stresses. In this review, we describe current body of literature on the role of several common histone methylations and their modifying enzymes in heart development, congenital and adult heart diseases.

A Physical Heart Failure Simulation System Utilizing the Total Artificial Heart and Modified Donovan Mock Circulation.

Science.gov (United States)

Crosby, Jessica R; DeCook, Katrina J; Tran, Phat L; Betterton, Edward; Smith, Richard G; Larson, Douglas F; Khalpey, Zain I; Burkhoff, Daniel; Slepian, Marvin J

2017-07-01

With the growth and diversity of mechanical circulatory support (MCS) systems entering clinical use, a need exists for a robust mock circulation system capable of reliably emulating and reproducing physiologic as well as pathophysiologic states for use in MCS training and inter-device comparison. We report on the development of such a platform utilizing the SynCardia Total Artificial Heart and a modified Donovan Mock Circulation System, capable of being driven at normal and reduced output. With this platform, clinically relevant heart failure hemodynamics could be reliably reproduced as evidenced by elevated left atrial pressure (+112%), reduced aortic flow (-12.6%), blunted Starling-like behavior, and increased afterload sensitivity when compared with normal function. Similarly, pressure-volume relationships demonstrated enhanced sensitivity to afterload and decreased Starling-like behavior in the heart failure model. Lastly, the platform was configured to allow the easy addition of a left ventricular assist device (HeartMate II at 9600 RPM), which upon insertion resulted in improvement of hemodynamics. The present configuration has the potential to serve as a viable system for training and research, aimed at fostering safe and effective MCS device use. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Magnetic field effects on the open circuit potential of ferromagnetic electrodes in corroding solutions.

Science.gov (United States)

Dass, Amala; Counsil, Joseph A; Gao, Xuerong; Leventis, Nicholas

2005-06-02

Magnetic fields shift the open circuit potential (OCP) of ferromagnetic electrodes (Fe, Co, and Ni) in corroding solutions. The OCP changes we observe (a) follow the series Fe>Co>Ni; (b) increase with the magnetic flux density; (c) reach a maximum with disk electrodes approximately 1 mm in diameter; and (d) depend on the orientation of the electrode. We report that when the surface of the electrode is oriented parallel (theta = 90 degrees) or perpendicular (theta = 0 degrees) to the magnetic field, the open circuit potential moves in opposite directions (positive and negative, respectively) with the largest changes occurring when the electrode surface is parallel to the magnetic field. Nonconvective sleeve electrodes produce the same behavior. The overall experimental evidence suggests that the magnetic field changes the OCP by modifying the surface concentrations of the paramagnetic participants in the corrosion process of the ferromagnetic electrode by species in solution; this in turn is accomplished by imposing a field-gradient driven mode of mass transfer upon paramagnetic species in solution (magnetophoresis). Simulations of the magnetic field around the ferromagnetic electrode at the two extreme orientations considered here show that in one case (theta = 90 degrees) field gradients actually repel, while in the other case (theta = 0 degrees) they attract paramagnetic species in the vicinity of the electrode.

Cyanotic congenital heart disease and atherosclerosis.

Science.gov (United States)

Tarp, Julie Bjerre; Jensen, Annette Schophuus; Engstrøm, Thomas; Holstein-Rathlou, Niels-Henrik; Søndergaard, Lars

2017-06-01

Improved treatment options in paediatric cardiology and congenital heart surgery have resulted in an ageing population of patients with cyanotic congenital heart disease (CCHD). The risk of acquired heart disease such as atherosclerosis increases with age.Previous studies have speculated whether patients with CCHD are protected against atherosclerosis. Results have shown that the coronary arteries of patients with CCHD are free from plaques and stenosis. Decreased carotid intima-media thickness and low total plasma cholesterol may indicate a reduced risk of later development of atherosclerosis. However, the evidence is still sparse and questionable, and a reasonable explanation for the decreased risk of developing atherosclerosis in patients with CCHD is still missing.This review provides an overview of what is known about the prevalence and potential causes of the reduced risk of atherosclerosis in patients with CCHD. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

The hippo pathway in heart development, regeneration, and diseases.

Science.gov (United States)

Zhou, Qi; Li, Li; Zhao, Bin; Guan, Kun-Liang

2015-04-10

The heart is the first organ formed during mammalian development. A properly sized and functional heart is vital throughout the entire lifespan. Loss of cardiomyocytes because of injury or diseases leads to heart failure, which is a major cause of human morbidity and mortality. Unfortunately, regenerative potential of the adult heart is limited. The Hippo pathway is a recently identified signaling cascade that plays an evolutionarily conserved role in organ size control by inhibiting cell proliferation, promoting apoptosis, regulating fates of stem/progenitor cells, and in some circumstances, limiting cell size. Interestingly, research indicates a key role of this pathway in regulation of cardiomyocyte proliferation and heart size. Inactivation of the Hippo pathway or activation of its downstream effector, the Yes-associated protein transcription coactivator, improves cardiac regeneration. Several known upstream signals of the Hippo pathway such as mechanical stress, G-protein-coupled receptor signaling, and oxidative stress are known to play critical roles in cardiac physiology. In addition, Yes-associated protein has been shown to regulate cardiomyocyte fate through multiple transcriptional mechanisms. In this review, we summarize and discuss current findings on the roles and mechanisms of the Hippo pathway in heart development, injury, and regeneration. © 2015 American Heart Association, Inc.

Autonomic innervation of the heart. Role of molecular imaging

Energy Technology Data Exchange (ETDEWEB)

Slart, Riemer H.J.A; Elsinga, Philip H. [Univ. Medical Center Groningen (Netherlands). Nuclear Medicine and Molecular Imaging; Tio, Rene A. [Univ. Medical Center Groningen (Netherlands). Thorax Center Cardiology; Schwaiger, Markus (ed.) [Technische Univ. Muenchen Klinikum Rechts der Isar (Germany). Nuklearmedizinische Klinik

2015-03-01

Reviews in detail the value of SPECT-CT and PET-CT in the imaging of cardiac innervation. Details the role of imaging in a range of conditions and diseases. Includes important background on pathophysiology, tracers, radiopharmaceutical production, and kinetic modeling software. This book explains in detail the potential value of the hybrid modalities, SPECT-CT and PET-CT, in the imaging of cardiac innervation in a wide range of conditions and diseases, including ischemic heart disease, diabetes mellitus, heart failure, amyloidosis, heart transplantation, and ventricular arrhythmias. Imaging of the brain-heart axis in neurodegenerative disease and stress and of cardiotoxicity is also discussed. The roles of the various available tracers are fully considered, and individual chapters address radiopharmaceutical development under GMP, imaging physics, and kinetic modeling software. Highly relevant background information is included on the autonomic nervous system of the heart and its pathophysiology, and in addition future perspectives are discussed. Awareness of the importance of autonomic innervation of the heart for the optimal management of cardiac patients is growing, and there is an evident need for objective measurement techniques or imaging modalities. In this context, Autonomic Innervation of the Heart will be of wide interest to clinicians, researchers, and industry.

Autonomic innervation of the heart. Role of molecular imaging

International Nuclear Information System (INIS)

Slart, Riemer H.J.A; Elsinga, Philip H.; Tio, Rene A.; Schwaiger, Markus

2015-01-01

Reviews in detail the value of SPECT-CT and PET-CT in the imaging of cardiac innervation. Details the role of imaging in a range of conditions and diseases. Includes important background on pathophysiology, tracers, radiopharmaceutical production, and kinetic modeling software. This book explains in detail the potential value of the hybrid modalities, SPECT-CT and PET-CT, in the imaging of cardiac innervation in a wide range of conditions and diseases, including ischemic heart disease, diabetes mellitus, heart failure, amyloidosis, heart transplantation, and ventricular arrhythmias. Imaging of the brain-heart axis in neurodegenerative disease and stress and of cardiotoxicity is also discussed. The roles of the various available tracers are fully considered, and individual chapters address radiopharmaceutical development under GMP, imaging physics, and kinetic modeling software. Highly relevant background information is included on the autonomic nervous system of the heart and its pathophysiology, and in addition future perspectives are discussed. Awareness of the importance of autonomic innervation of the heart for the optimal management of cardiac patients is growing, and there is an evident need for objective measurement techniques or imaging modalities. In this context, Autonomic Innervation of the Heart will be of wide interest to clinicians, researchers, and industry.

THE POSSIBLE IMPACT OF L5 MAGNETOGRAMS ON NON-POTENTIAL SOLAR CORONAL MAGNETIC FIELD SIMULATIONS

Energy Technology Data Exchange (ETDEWEB)

Weinzierl, Marion; Yeates, Anthony R. [Department of Mathematical Sciences, Durham University South Road, Durham DH1 3LE (United Kingdom); Mackay, Duncan H. [School of Mathematics and Statistics, University of St. Andrews North Haugh, St. Andrews, Fife KY16 9SS (United Kingdom); Pevtsov, Alexei A., E-mail: marion.weinzierl@durham.ac.uk [National Solar Observatory 3010 Coronal Loop, sunspot NM 88349 (United States)

2016-09-10

The proposed Carrington-L5 mission would bring instruments to the L5 Lagrange point to provide us with crucial data for space weather prediction. To assess the importance of including a magnetograph, we consider the possible differences in non-potential solar coronal magnetic field simulations when magnetograph observations are available from the L5 point, compared with an L1-based field of view (FOV). A timeseries of synoptic radial magnetic field maps is constructed to capture the emergence of two active regions from the L5 FOV. These regions are initially absent in the L1 magnetic field maps, but are included once they rotate into the L1 FOV. Non-potential simulations for these two sets of input data are compared in detail. Within the bipolar active regions themselves, differences in the magnetic field structure can exist between the two simulations once the active regions are included in both. These differences tend to reduce within 5 days of the active region being included in L1. The delayed emergence in L1 can, however, lead to significant persistent differences in long-range connectivity between the active regions and the surrounding fields, and also in the global magnetic energy. In particular, the open magnetic flux and the location of open magnetic footpoints, are sensitive to capturing the real-time of emergence. These results suggest that a magnetograph at L5 could significantly improve predictions of the non-potential corona, the interplanetary magnetic field, and of solar wind source regions on the Sun.

Effect of aerobic training on heart rate recovery in patients with established heart disease; a systematic review

NARCIS (Netherlands)

Snoek, Johan A.; Van Berkel, Sietske; Van Meeteren, Nico; Backx, Frank J G; Daanen, Hein A M

2013-01-01

Background: Although a delayed decrease in heart rate during the first minute after graded exercise has been identified as a powerful predictor of overall mortality in cardiac patients, the potential to influence this risk factor by aerobic training remains to be proven. Objective: The aim was to

Outflow tract septation and the aortic arch system in reptiles: lessons for understanding the mammalian heart.

Science.gov (United States)

Poelmann, Robert E; Gittenberger-de Groot, Adriana C; Biermans, Marcel W M; Dolfing, Anne I; Jagessar, Armand; van Hattum, Sam; Hoogenboom, Amanda; Wisse, Lambertus J; Vicente-Steijn, Rebecca; de Bakker, Merijn A G; Vonk, Freek J; Hirasawa, Tatsuya; Kuratani, Shigeru; Richardson, Michael K

2017-01-01

Cardiac outflow tract patterning and cell contribution are studied using an evo-devo approach to reveal insight into the development of aorto-pulmonary septation. We studied embryonic stages of reptile hearts (lizard, turtle and crocodile) and compared these to avian and mammalian development. Immunohistochemistry allowed us to indicate where the essential cell components in the outflow tract and aortic sac were deployed, more specifically endocardial, neural crest and second heart field cells. The neural crest-derived aorto-pulmonary septum separates the pulmonary trunk from both aortae in reptiles, presenting with a left visceral and a right systemic aorta arising from the unseptated ventricle. Second heart field-derived cells function as flow dividers between both aortae and between the two pulmonary arteries. In birds, the left visceral aorta disappears early in development, while the right systemic aorta persists. This leads to a fusion of the aorto-pulmonary septum and the aortic flow divider (second heart field population) forming an avian aorto-pulmonary septal complex. In mammals, there is also a second heart field-derived aortic flow divider, albeit at a more distal site, while the aorto-pulmonary septum separates the aortic trunk from the pulmonary trunk. As in birds there is fusion with second heart field-derived cells albeit from the pulmonary flow divider as the right 6th pharyngeal arch artery disappears, resulting in a mammalian aorto-pulmonary septal complex. In crocodiles, birds and mammals, the main septal and parietal endocardial cushions receive neural crest cells that are functional in fusion and myocardialization of the outflow tract septum. Longer-lasting septation in crocodiles demonstrates a heterochrony in development. In other reptiles with no indication of incursion of neural crest cells, there is either no myocardialized outflow tract septum (lizard) or it is vestigial (turtle). Crocodiles are unique in bearing a central shunt, the

Effect of Membrane Tension on the Electric Field and Dipole Potential of Lipid Bilayer Membrane

Science.gov (United States)

Warshaviak, Dora Toledo; Muellner, Michael J.; Chachisvilis, Mirianas

2011-01-01

The dipole potential of lipid bilayer membrane controls the difference in permeability of the membrane to oppositely charged ions. We have combined molecular dynamics (MD) simulations and experimental studies to determine changes in electric field and electrostatic potential of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) lipid bilayer in response to applied membrane tension. MD simulations based on CHARMM36 force field showed that electrostatic potential of DOPC bilayer decreases by ~45 mV in the physiologically relevant range of membrane tension values (0 to 15 dyn/cm). The electrostatic field exhibits a peak (~0.8×109 V/m) near the water/lipid interface which shifts by 0.9 Å towards the bilayer center at 15 dyn/cm. Maximum membrane tension of 15 dyn/cm caused 6.4% increase in area per lipid, 4.7% decrease in bilayer thickness and 1.4% increase in the volume of the bilayer. Dipole-potential sensitive fluorescent probes were used to detect membrane tension induced changes in DOPC vesicles exposed to osmotic stress. Experiments confirmed that dipole potential of DOPC bilayer decreases at higher membrane tensions. These results are suggestive of a potentially new mechanosensing mechanism by which mechanically induced structural changes in the lipid bilayer membrane could modulate the function of membrane proteins by altering electrostatic interactions and energetics of protein conformational states. PMID:21722624

Heart rate index

DEFF Research Database (Denmark)

Haedersdal, C; Pedersen, F H; Svendsen, J H

1992-01-01

after the myocardial infarction. A significant correlation (Spearman's correlation coefficient rs, p less than 0.05) was found between LVEF at rest and the following variables assessed at exercise test: 1) the heart rate at rest, 2) rise in heart rate, 3) ratio between maximal heart rate and heart rate...... at rest, 4) rise in systolic blood pressure, 5) rate pressure product at rest, 6) rise in rate pressure product, 7) ratio (rHR) between maximal rate pressure product and rate pressure product at rest, 8) total exercise time. The heart rate was corrected for effects caused by age (heart index (HR...

Cyanotic Congenital Heart Defects – literature review

Directory of Open Access Journals (Sweden)

Vlad Drăgoi

2017-11-01

Full Text Available Congenital heart defects are one of the most interesting and important chapters regarding abnormal fetal growth pathology. The objective of this article is to present a literature review for the main cyanotic congenital heart defects. The ones presented in the article are: tetralogy of Fallot, transposition of the great vessels, double outlet right ventricle, truncus arteriosus, total anomalous pulmonary venous circulation and additional information regarding very rare malformations such as pentalogy of Cantrell and Uhl anomaly. An early and precise identification of congenital heart defects is an important step in an accurate follow-up of a potential problematic pregnancy. Knowing the sonographic aspect, associated pathology and the current available treatment procedures are vital for the fetal outcome and for the physician to adapt the right management in every situation that might appear during the pregnancy and in the neonatal period.

On the unlikeliness of multi-field inflation: bounded random potentials and our vacuum

International Nuclear Information System (INIS)

Battefeld, Diana; Battefeld, Thorsten; Schulz, Sebastian

2012-01-01

Based on random matrix theory, we compute the likelihood of saddles and minima in a class of random potentials that are softly bounded from above and below, as required for the validity of low energy effective theories. Imposing this bound leads to a random mass matrix with non-zero mean of its entries. If the dimensionality of field-space is large, inflation is rare, taking place near a saddle point (if at all), since saddles are more likely than minima or maxima for common values of the potential. Due to the boundedness of the potential, the latter become more ubiquitous for rare low/large values respectively. Based on the observation of a positive cosmological constant, we conclude that the dimensionality of field-space after (and most likely during) inflation has to be low if no anthropic arguments are invoked, since the alternative, encountering a metastable deSitter vacuum by chance, is extremely unlikely

Electric Mars: A large trans-terminator electric potential drop on closed magnetic field lines above Utopia Planitia

Science.gov (United States)

Collinson, Glyn; Mitchell, David; Xu, Shaosui; Glocer, Alex; Grebowsky, Joseph; Hara, Takuya; Lillis, Robert; Espley, Jared; Mazelle, Christian; Sauvaud, Jean-André; Fedorov, Andrey; Liemohn, Mike; Andersson, Laila; Jakosky, Bruce

2017-02-01

Parallel electric fields and their associated electric potential structures play a crucial role in ionospheric-magnetospheric interactions at any planet. Although there is abundant evidence that parallel electric fields play key roles in Martian ionospheric outflow and auroral electron acceleration, the fields themselves are challenging to directly measure due to their relatively weak nature. Using measurements by the Solar Wind Electron Analyzer instrument aboard the NASA Mars Atmosphere and Volatile EvolutioN (MAVEN) Mars Scout, we present the discovery and measurement of a substantial (ΦMars=7.7 ± 0.6 V) parallel electric potential drop on closed magnetic field lines spanning the terminator from day to night above the great impact basin of Utopia Planitia, a region largely free of crustal magnetic fields. A survey of the previous 26 orbits passing over a range of longitudes revealed similar signatures on seven orbits, with a mean potential drop (ΦMars) of 10.9 ± 0.8 V, suggestive that although trans-terminator electric fields of comparable strength are not ubiquitous, they may be common, at least at these northerly latitudes.

Electric Mars: A Large Trans-Terminator Electric Potential Drop on Closed Magnetic Field Lines Above Utopia Planitia

Science.gov (United States)

Collinson, Glyn; Mitchell, David; Xu, Shaosui; Glocer, Alex; Grebowsky, Joseph; Hara, Takuya; Lillis, Robert; Espley, Jared; Mazelle, Christian; Sauvaud, Jean-Andre

2017-01-01

Abstract Parallel electric fields and their associated electric potential structures play a crucial role inionospheric-magnetospheric interactions at any planet. Although there is abundant evidence that parallel electric fields play key roles in Martian ionospheric outflow and auroral electron acceleration, the fields themselves are challenging to directly measure due to their relatively weak nature. Using measurements by the Solar Wind Electron Analyzer instrument aboard the NASA Mars Atmosphere and Volatile EvolutioN(MAVEN) Mars Scout, we present the discovery and measurement of a substantial (Phi) Mars 7.7 +/-0.6 V) parallel electric potential drop on closed magnetic field lines spanning the terminator from day to night above the great impact basin of Utopia Planitia, a region largely free of crustal magnetic fields. A survey of the previous 26 orbits passing over a range of longitudes revealed similar signatures on seven orbits, with a mean potential drop (Phi) Mars of 10.9 +/- 0.8 V, suggestive that although trans-terminator electric fields of comparable strength are not ubiquitous, they may be common, at least at these northerly latitudes.

Plasma Amino Acid Abnormalities in Chronic Heart Failure. Mechanisms, Potential Risks and Targets in Human Myocardium Metabolism

Directory of Open Access Journals (Sweden)

Roberto Aquilani

2017-11-01

Full Text Available The goal of this study was to measure arterial amino acid levels in patients with chronic heart failure (CHF, and relate them to left ventricular function and disease severity. Amino acids (AAs play a crucial role for heart protein-energy metabolism. In heart failure, arterial AAs, which are the major determinant of AA uptake by the myocardium, are rarely measured. Forty-one subjects with clinically stable CHF (New York Heart Association (NYHA class II to IV were analyzed. After overnight fasting, blood samples from the radial artery were taken to measure AA concentrations. Calorie (KcalI, protein-, fat-, carbohydrate-intake, resting energy expenditure (REE, total daily energy expenditure (REE × 1.3, and cardiac right catheterization variables were all measured. Eight matched controls were compared for all measurements, with the exception of cardiac catheterization. Compared with controls, CHF patients had reduced arterial AA levels, of which both their number and reduced rates are related to Heart Failure (HF severity. Arterial aspartic acid correlated with stroke volume index (r = 0.6263; p < 0.0001 and cardiac index (r = 0.4243; p = 0.0028. The value of arterial aspartic acid (µmol/L multiplied by the cardiac index was associated with left ventricular ejection fraction (r = 0.3765; p = 0.0076. All NYHA groups had adequate protein intake (≥1.1 g/kg/day and inadequate calorie intake (KcalI < REE × 1.3 was found only in class IV patients. This study showed that CHF patients had reduced arterial AA levels directly related to clinical disease severity and left ventricular dysfunction.

Evanescent field: A potential light-tool for theranostics application

Science.gov (United States)

Polley, Nabarun; Singh, Soumendra; Giri, Anupam; Pal, Samir Kumar

2014-03-01

A noninvasive or minimally invasive optical approach for theranostics, which would reinforce diagnosis, treatment, and preferably guidance simultaneously, is considered to be major challenge in biomedical instrument design. In the present work, we have developed an evanescent field-based fiber optic strategy for the potential theranostics application in hyperbilirubinemia, an increased concentration of bilirubin in the blood and is a potential cause of permanent brain damage or even death in newborn babies. Potential problem of bilirubin deposition on the hydroxylated fiber surface at physiological pH (7.4), that masks the sensing efficacy and extraction of information of the pigment level, has also been addressed. Removal of bilirubin in a blood-phantom (hemoglobin and human serum albumin) solution from an enhanced level of 77 μM/l (human jaundice >50 μM/l) to ˜30 μM/l (normal level ˜25 μM/l in human) using our strategy has been successfully demonstrated. In a model experiment using chromatography paper as a mimic of biological membrane, we have shown efficient degradation of the bilirubin under continuous monitoring for guidance of immediate/future course of action.

Effect of Mobile Phone Radiofrequency Electromagnetic Fields on ...

African Journals Online (AJOL)

Summary: Since cell phones emit radiofrequency electromagnetic fields (EMFs), this study tested the hypothesis that cell phones placed near the heart may interfere with the electrical rhythm of the heart or affect the blood pressure. Following informed consent, eighteen randomly selected apparently healthy male volunteers ...

Dimensional analysis of heart rate variability in heart transplant recipients

Energy Technology Data Exchange (ETDEWEB)

Zbilut, J.P.; Mayer-Kress, G.; Geist, K.

1987-01-01

We discuss periodicities in the heart rate in normal and transplanted hearts. We then consider the possibility of dimensional analysis of these periodicities in transplanted hearts and problems associated with the record.

Million Hearts: Key to Collaboration to Reduce Heart Disease

Science.gov (United States)

Brinkman, Patricia

2016-01-01

Extension has taught successful classes to address heart disease, yet heart disease remains the number one killer in the United States. The U.S. government's Million Hearts initiative seeks collaboration among colleges, local and state health departments, Extension and other organizations, and medical providers in imparting a consistent message…

Solar system tests of scalar field models with an exponential potential

International Nuclear Information System (INIS)

Paramos, J.; Bertolami, O.

2008-01-01

We consider a scenario where the dynamics of a scalar field is ruled by an exponential potential, such as those arising from some quintessence-type models, and aim at obtaining phenomenological manifestations of this entity within our Solar System. To do so, we assume a perturbative regime, derive the perturbed Schwarzschild metric, and extract the relevant post-Newtonian parameters.

Unraveling nonadiabatic ionization and Coulomb potential effect in strong-field photoelectron holography.

Science.gov (United States)

Song, Xiaohong; Lin, Cheng; Sheng, Zhihao; Liu, Peng; Chen, Zhangjin; Yang, Weifeng; Hu, Shilin; Lin, C D; Chen, Jing

2016-06-22

Strong field photoelectron holography has been proposed as a means for interrogating the spatial and temporal information of electrons and ions in a dynamic system. After ionization, part of the electron wave packet may directly go to the detector (the reference wave), while another part may be driven back and scatters off the ion(the signal wave). The interference hologram of the two waves may be used to extract target information embedded in the collision process. Unlike conventional optical holography, however, propagation of the electron wave packet is affected by the Coulomb potential as well as by the laser field. In addition, electrons are emitted over the whole laser pulse duration, thus multiple interferences may occur. In this work, we used a generalized quantum-trajectory Monte Carlo method to investigate the effect of Coulomb potential and the nonadiabatic subcycle ionization on the photoelectron hologram. We showed that photoelectron hologram can be well described only when the effect of nonadiabatic ionization is accounted for, and Coulomb potential can be neglected only in the tunnel ionization regime. Our results help paving the way for establishing photoelectron holography for probing spatial and dynamic properties of atoms and molecules.

REVIEW OF HEART DISEASE PREDICTION SYSTEM USING DATA MINING AND HYBRID INTELLIGENT TECHNIQUES

Directory of Open Access Journals (Sweden)

R. Chitra

2013-07-01

Full Text Available The Healthcare industry generally clinical diagnosis is done mostly by doctor’s expertise and experience. Computer Aided Decision Support System plays a major role in medical field. With the growing research on heart disease predicting system, it has become important to categories the research outcomes and provides readers with an overview of the existing heart disease prediction techniques in each category. Neural Networks are one of many data mining analytical tools that can be utilized to make predictions for medical data. From the study it is observed that Hybrid Intelligent Algorithm improves the accuracy of the heart disease prediction system. The commonly used techniques for Heart Disease Prediction and their complexities are summarized in this paper.

Wine and heart health

Science.gov (United States)

Health and wine; Wine and heart disease; Preventing heart disease - wine; Preventing heart disease - alcohol ... more often just to lower your risk of heart disease. Heavier drinking can harm the heart and ...

Possible health hazards for cardiac pacemaker wearers from exposure to electromagnetic fields. L'exposition aux champs electromagnetiques: Risques pour la sante des porteurs de stimulateur cardiaque

Energy Technology Data Exchange (ETDEWEB)

1988-03-01

Cardiac pacemakers are used to provide electrical stimulation to the heart when the heart's natural rhythm is interrupted. This study shows that they can be susceptible to electromagnetic fields. Pacemakers are well protected against common electromagnetic fields, such as those from household appliances. But intense electomagnetic fields, such as those found in some industrial settings, could affect the functioning of the pacemaker. Such interference may cause the pacemaker wearer to feel dizzy or experience an accelerated heartbeat. While this is not fatal, the pacemaker wearer should try to move away from the source of the interfering field and avoid situations in which interference could arise. After experiencing any of these symptoms, the pacemaker wearer should contact a physician. Potential sources of electromagnetic interference should be identified and characterized to determine if there could be an interference hazard. Exposure to interfering electomagnetic fields should be minimized. 7 refs., 1 fig.

Evolving Concepts of Pulmonary Hypertension Secondary to Left Heart Disease.

Science.gov (United States)

Ramu, Bhavadharini; Thenappan, Thenappan

2016-04-01

Pulmonary hypertension associated with left heart disease is the most common form of pulmonary hypertension. Although its pathophysiology remains incompletely understood, it is now well recognized that the presence of pulmonary hypertension is associated with a worse prognosis. Right ventricular failure has independent and additive prognostic value over pulmonary hypertension for adverse outcomes in left heart disease. Recently, several new terminologies have been introduced to better define and characterize the nature and severity of pulmonary hypertension. Several new treatment options including the use of pulmonary arterial hypertension specific therapies are being considered, but there is lack of evidence. Here, we review the recent advances in this field and summarize the diagnostic and therapeutic modalities of use in the management of pulmonary hypertension associated with left heart disease.

MOTION MODELLINGUSINGCONCEPTS OF FUZZY ARTIFICIAL POTENTIAL FIELDS

Directory of Open Access Journals (Sweden)

O. Motlagh

2010-12-01

Full Text Available Artificial potential fields (APF are well established for reactive navigation of mobile robots. This paper describes a fast and robust fuzzy-APF on an ActivMedia AmigoBot. Obstacle-related information is fuzzified by using sensory fusion, which results in a shorter runtime. In addition, the membership functions of obstacle direction and range have been merged into one function, obtaining a smaller block of rules. The system is tested in virtual environments with non-concave obstacles. Then, the paper describes a new approach to motion modelling where the motion of intelligent travellers is modelled by consecutive path segments. In previous work, the authors described a reliable motion modelling technique using causal inference of fuzzy cognitive maps (FCM which has been efficiently modified for the purpose of this contribution. Results and analysis are given to demonstrate the efficiency and accuracy of the proposed motion modelling algorithm.

Lung and heart dose volume analyses with CT simulator in radiation treatment of breast cancer

International Nuclear Information System (INIS)

Das, Indra J.; Cheng, Elizabeth C.; Freedman, Gary; Fowble, Barbara

1998-01-01

Purpose: Radiation pneumonitis and cardiac effects are directly related to the irradiated lung and heart volumes in the treatment fields. The central lung distance (CLD) from a tangential breast radiograph is shown to be a significant indicator of ipsilateral irradiated lung volume. Retrospective analysis of the pattern of dose volume of lung and heart with actual volume data from a CT simulator in the treatment of breast cancer is presented with respect to CLD. Methods and Materials: The heart and lung volumes in the tangential treatment fields were analyzed in 108 consecutive cases (52 left and 56 right breast) referred for CT simulation. All patients in this study were immobilized and placed on an inclined breast board in actual treatment setup. Both arms were stretched over head to avoid collision with the scanner aperture. Radiopaque marks were placed on the medial and lateral borders of the tangential fields. All patients were scanned in spiral mode with slice width and thickness of 3 mm each, respectively. The lung and heart structures as well as irradiated areas were delineated on each slice and respective volumes were accurately measured. The treatment beam parameters were recorded and the digitally reconstructed radiographs (DRRs) were generated for the measurement of the CLD and analysis. Results: Using CT data the mean volume and standard deviation of left and right lungs were 1307.7 ± 297.7 cm 3 and 1529.6 ± 298.5 cm 3 , respectively. The magnitude of irradiated volume in left and right lung is nearly equal for the same CLD that produces different percent irradiated volumes (PIV). The left and right PIV lungs are 8.3 ± 4.7% and 6.6 ± 3.7%, respectively. The PIV data have shown to correlate with CLD with second- and third-degree polynomials; however, in this study a simple straight line regression is used to provide better confidence than the higher order polynomials. The regression lines for the left and right breasts are very different based on

Men and Heart Disease

Science.gov (United States)

... Pressure Salt Cholesterol Million Hearts® WISEWOMAN Men and Heart Disease Fact Sheet Recommend on Facebook Tweet Share Compartir Source: Interactive Atlas of Heart Disease and Stroke Heart Disease Facts in Men Heart disease is the leading ...

Domestic and foreign trends in the prevalence of heart failure and the necessity of next-generation artificial hearts: a survey by the Working Group on Establishment of Assessment Guidelines for Next-Generation Artificial Heart Systems.

Science.gov (United States)

Tatsumi, Eisuke; Nakatani, Takeshi; Imachi, Kou; Umezu, Mitsuo; Kyo, Shun-Ei; Sase, Kazuhiro; Takatani, Setsuo; Matsuda, Hikaru

2007-01-01

A series of guidelines for development and assessment of next-generation medical devices has been drafted under an interagency collaborative project by the Ministry of Health, Labor and Welfare and the Ministry of Economy, Trade and Industry. The working group for assessment guidelines of next-generation artificial hearts reviewed the trend in the prevalence of heart failure and examined the potential usefulness of such devices in Japan and in other countries as a fundamental part of the process of establishing appropriate guidelines. At present, more than 23 million people suffer from heart failure in developed countries, including Japan. Although Japan currently has the lowest mortality from heart failure among those countries, the number of patients is gradually increasing as our lifestyle becomes more Westernized; the associated medical expenses are rapidly growing. The number of heart transplantations, however, is limited due to the overwhelming shortage of donor hearts, not only in Japan but worldwide. Meanwhile, clinical studies and surveys have revealed that the major causes of death in patients undergoing long-term use of ventricular assist devices (VADs) were infection, thrombosis, and mechanical failure, all of which are typical of VADs. It is therefore of urgent and universal necessity to develop next-generation artificial hearts that have excellent durability to provide at least 2 years of event-free operation with a superior quality of life and that can be used for destination therapy to save patients with irreversible heart failure. It is also very important to ensure that an environment that facilitates the development, testing, and approval evaluation processes of next-generation artificial hearts be established as soon as possible.

Behavioral correlates of heart rates of free-living Greater White-fronted Geese

Science.gov (United States)

Ely, Craig R.; Ward, D.H.; Bollinger, K.S.

1999-01-01

We simultaneously monitored the heart rate and behavior of nine free-living Greater White-fronted Geese (Anser albifrons) on their wintering grounds in northern California. Heart rates of wild geese were monitored via abdominally-implanted radio transmitters with electrodes that received electrical impulses of the heart and emitted a radio signal with each ventricular contraction. Post-operative birds appeared to behave normally, readily rejoining flocks and flying up to 15 km daily from night-time roost sites to feed in surrounding agricultural fields. Heart rates varied significantly among individuals and among behaviors, and ranged from less than 100 beats per minute (BPM) during resting, to over 400 BPM during flight. Heart rates varied from 80 to 140 BPM during non-strenuous activities such as walking, feeding, and maintenance activities, to about 180 BPM when birds became alert, and over 400 BPM when birds were startled, even if they did not take flight. Postflight heart rate recovery time averaged postures, as heart rates were context-dependent, and were highest in initial encounters among individuals. Instantaneous measures of physiological parameters, such as heart rate, are often better indicators of the degree of response to external stimuli than visual observations and can be used to improve estimates of energy expenditure based solely on activity data.

Classes of Heart Failure

Science.gov (United States)

... Introduction Types of Heart Failure Classes of Heart Failure Heart Failure in Children Advanced Heart Failure • Causes and ... and Advanced HF • Tools and Resources • Personal Stories Heart Failure Questions to Ask Your Doctor Use these questions ...

Functionality of the baroreceptor nerves in heart rate regulation

DEFF Research Database (Denmark)

Ottesen, Johnny T.; Olufsen, Mette

2011-01-01

are a consequence of the memory encapsulated by the models, and the nonlinearity gives rise to sigmoidal response curves. The nonlinear afferent baroreceptor models are coupled with an effector model, and the coupled model has been used to predict baroreceptor feedback regulation of heart rate during postural...... change from sitting to standing and during head-up tilt. The efferent model couples the afferent nerve paths to the sympathetic and parasympathetic outflow, and subsequently predicts the build up of an action potential at the sinus knot of the heart. In this paper, we analyze the nonlinear afferent model...... and show that the coupled model is able to predict heart rate regulation using blood pressure data as an input...

Machine learning in heart failure: ready for prime time.

Science.gov (United States)

Awan, Saqib Ejaz; Sohel, Ferdous; Sanfilippo, Frank Mario; Bennamoun, Mohammed; Dwivedi, Girish

2018-03-01

The aim of this review is to present an up-to-date overview of the application of machine learning methods in heart failure including diagnosis, classification, readmissions and medication adherence. Recent studies have shown that the application of machine learning techniques may have the potential to improve heart failure outcomes and management, including cost savings by improving existing diagnostic and treatment support systems. Recently developed deep learning methods are expected to yield even better performance than traditional machine learning techniques in performing complex tasks by learning the intricate patterns hidden in big medical data. The review summarizes the recent developments in the application of machine and deep learning methods in heart failure management.

Heart valve surgery

Science.gov (United States)

... replacement; Valve repair; Heart valve prosthesis; Mechanical valves; Prosthetic valves ... surgery. Your heart valve has been damaged by infection ( endocarditis ). You have received a new heart valve ...

Reconstruction of the Scalar Field Potential in Inflationary Models with a Gauss-Bonnet term

Science.gov (United States)

Koh, Seoktae; Lee, Bum-Hoon; Tumurtushaa, Gansukh

2017-06-01

We consider inflationary models with a Gauss-Bonnet term to reconstruct the scalar-field potentials and the Gauss-Bonnet coupling functions. Both expressions are derived from the observationally favored configurations of ns and r . Our result implies that, for the reconstructed potentials and coupling functions, the blue tilt of inflationary tensor fluctuations can be realized. To achieve a blue tilt for the inflationary tensor fluctuations, a scalar field must climb up its potential before rolling down. We further investigate the properties of propagation of the perturbation modes in Friedmann-Robertson-Walker spacetime. For the reconstructed configurations that give rise to the blue tilt for the inflationary tensor fluctuations, we show that the ghosts and instabilities are absent with the superluminal propagation speeds for the scalar perturbation modes, whereas the propagation speeds of the tensor perturbations are subluminal.

Heart failure due to severe myocardial calcification

International Nuclear Information System (INIS)

Takahashi, Shouichi; Maida, Kiyoshi; Yokoyama, Hitoshi; Tanaka, Shigeo

1993-01-01

A 28-year-old female who had had irradiation on the chest wall at the age of 5 as a remedy for keloid granulation after burn, recently developed congestive heart failure. Severe tricuspid regurgitation was demonstrated by echocardiography with a certain calcification in the cardiac shadow on chest radiogram. Calcified right ventricle and ventricular septum were noticed operatively, which disturbed ventricular motion and also caused tricuspid valve deformity. These calcified myocardium apparently corresponded with the irradiation field. After tricuspid valve replacement, she regained physical activity satisfactorily without congestive heart failure. Because she had no other known causes of cardiac calcification such as hypercalcemia, myocarditis, myocardial infarction or renal diseases, irradiation on the chest wall could be responsible for the severe myocardial calcification. (author)

Time and space-correlated plasma potential measurements in the near field of a coaxial Hall plasma discharge

International Nuclear Information System (INIS)

Smith, A. W.; Cappelli, M. A.

2009-01-01

Space- and time-correlated measurements of floating and plasma potential are made in the near field, external flow cathode region of a coaxial Hall plasma discharge using an emissive probe synchronized to quasicoherent fluctuations in discharge current. The luminous axial feature frequently observed in the near field of operating plasma accelerators is found to be concomitant with a spike in the plasma potential (and electron temperature). The structure of the plasma potential allows for multiple avenues for back-streaming ions to accelerate toward the discharge front pole and may pull some classes of ions toward the central axis. The fluctuations in plasma properties exhibit a complex structure at frequencies on the order of the so-called 'breathing mode' ionization instability often seen in these types of discharges. Most notably, the plasma potential appears to fluctuate in a helical fashion, resembling tilted drift waves rotating about the central axis. A simple analysis of these waves draws attention to the possible role that they may play in driving anomalous cross-field electron transport in the near field region.

Current-current correlation function in presence of chemical potential and external magnetic field

International Nuclear Information System (INIS)

Apresyan, E.A.

2017-01-01

The (2+1)-dimensional electron system was observed, where relation between the Green functions and conductivity was used. The current-current correlation function Π_μ_ν(B) for the fermion system was calculated in presence of non-quantizing magnetic field B, chemical potential η and gap m. From this function it is possible to obtain the equation for polarization operator calculated without the magnetic field. The result is also applicable for graphene