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  1. MEF2C silencing attenuates load-induced left ventricular hypertrophy by modulating mTOR/S6K pathway in mice.

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    Ana Helena M Pereira

    Full Text Available BACKGROUND: The activation of the members of the myocyte enhancer factor-2 family (MEF2A, B, C and D of transcription factors promotes cardiac hypertrophy and failure. However, the role of its individual components in the pathogenesis of cardiac hypertrophy remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we investigated whether MEF2C plays a role in mediating the left ventricular hypertrophy by pressure overload in mice. The knockdown of myocardial MEF2C induced by specific small interfering RNA (siRNA has been shown to attenuate hypertrophy, interstitial fibrosis and the rise of ANP levels in aortic banded mice. We detected that the depletion of MEF2C also results in lowered levels of both PGC-1alpha and mitochondrial DNA in the overloaded left ventricle, associated with enhanced AMP:ATP ratio. Additionally, MEF2C depletion was accompanied by defective activation of S6K in response to pressure overload. Treatment with the amino acid leucine stimulated S6K and suppressed the attenuation of left ventricular hypertrophy and fibrosis in the aforementioned aortic banded mice. CONCLUSION/SIGNIFICANCE: These findings represent new evidences that MEF2C depletion attenuates the hypertrophic responses to mechanical stress and highlight the potential of MEF2C to be a target for new therapies to cardiac hypertrophy and failure.

  2. Ablation of biglycan attenuates cardiac hypertrophy and fibrosis after left ventricular pressure overload.

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    Beetz, Nadine; Rommel, Carolin; Schnick, Tilman; Neumann, Elena; Lother, Achim; Monroy-Ordonez, Elsa Beatriz; Zeeb, Martin; Preissl, Sebastian; Gilsbach, Ralf; Melchior-Becker, Ariane; Rylski, Bartosz; Stoll, Monika; Schaefer, Liliana; Beyersdorf, Friedhelm; Stiller, Brigitte; Hein, Lutz

    2016-12-01

    Biglycan, a small leucine-rich proteoglycan, has been shown to play an important role in stabilizing fibrotic scars after experimental myocardial infarction. However, the role of biglycan in the development and regression of cardiomyocyte hypertrophy and fibrosis during cardiac pressure overload and unloading remains elusive. Thus, the aim of the present study was to assess the effect of biglycan on cardiac remodeling in a mouse model of left ventricular pressure overload and unloading. Left ventricular pressure overload induced by transverse aortic constriction (TAC) in mice resulted in left ventricular dysfunction, fibrosis and increased biglycan expression. Fluorescence- and magnetic-assisted sorting of cardiac cell types revealed upregulation of biglycan in the fibroblast population, but not in cardiomyocytes, endothelial cells or leukocytes after TAC. Removal of the aortic constriction (rTAC) after short-term pressure overload (3weeks) improved cardiac contractility and reversed ventricular hypertrophy but not fibrosis in wild-type (WT) mice. Biglycan ablation (KO) enhanced functional recovery but did not resolve cardiac fibrosis. After long-term TAC for 9weeks, ablation of biglycan attenuated the development of cardiac hypertrophy and fibrosis. In vitro, biglycan induced hypertrophy of neonatal rat cardiomyocytes and led to activation of a hypertrophic gene program. Putative downstream mediators of biglycan signaling include Rcan1, Abra and Tnfrsf12a. These genes were concordantly induced by TAC in WT but not in biglycan KO mice. Left ventricular pressure overload induces biglycan expression in cardiac fibroblasts. Ablation of biglycan improves cardiac function and attenuates left ventricular hypertrophy and fibrosis after long-term pressure overload. In vitro biglycan induces hypertrophy of cardiomyocytes, suggesting that biglycan may act as a signaling molecule between cell types to modulate cardiac remodeling. Copyright © 2016 Elsevier Ltd. All rights

  3. Myocardial connective tissue growth factor (CCN2/CTGF attenuates left ventricular remodeling after myocardial infarction.

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    Jørgen Gravning

    Full Text Available AIMS: Myocardial CCN2/CTGF is induced in heart failure of various etiologies. However, its role in the pathophysiology of left ventricular (LV remodeling after myocardial infarction (MI remains unresolved. The current study explores the role of CTGF in infarct healing and LV remodeling in an animal model and in patients admitted for acute ST-elevation MI. METHODS AND RESULTS: Transgenic mice with cardiac-restricted overexpression of CTGF (Tg-CTGF and non-transgenic littermate controls (NLC were subjected to permanent ligation of the left anterior descending coronary artery. Despite similar infarct size (area of infarction relative to area at risk 24 hours after ligation of the coronary artery in Tg-CTGF and NLC mice, Tg-CTGF mice disclosed smaller area of scar tissue, smaller increase of cardiac hypertrophy, and less LV dilatation and deterioration of LV function 4 weeks after MI. Tg-CTGF mice also revealed substantially reduced mortality after MI. Remote/peri-infarct tissue of Tg-CTGF mice contained reduced numbers of leucocytes, macrophages, and cells undergoing apoptosis as compared with NLC mice. In a cohort of patients with acute ST-elevation MI (n = 42 admitted to hospital for percutaneous coronary intervention (PCI serum-CTGF levels (s-CTGF were monitored and related to infarct size and LV function assessed by cardiac MRI. Increase in s-CTGF levels after MI was associated with reduced infarct size and improved LV ejection fraction one year after MI, as well as attenuated levels of CRP and GDF-15. CONCLUSION: Increased myocardial CTGF activities after MI are associated with attenuation of LV remodeling and improved LV function mediated by attenuation of inflammatory responses and inhibition of apoptosis.

  4. Blockade of KCa3.1 Attenuates Left Ventricular Remodeling after Experimental Myocardial Infarction

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    Chen-Hui Ju

    2015-07-01

    Full Text Available Background/Aims: After myocardial infarction (MI, cardiac fibrosis greatly contributes to left ventricular remodeling and heart failure. The intermediate-conductance calcium-activated potassium Channel (KCa3.1 has been recently proposed as an attractive target of fibrosis. The present study aimed to detect the effects of KCa3.1 blockade on ventricular remodeling following MI and its potential mechanisms. Methods: Myocardial expression of KCa3.1 was initially measured in a mouse MI model by Western blot and real time-polymerase chain reaction. Then after treatment with TRAM-34, a highly selective KCa3.1 blocker, heart function and fibrosis were evaluated by echocardiography, histology and immunohistochemistry. Furthermore, the role of KCa3.1 in neonatal mouse cardiac fibroblasts (CFs stimulated by angiotensin II (Ang II was tested. Results: Myocardium expressed high level of KCa3.1 after MI. Pharmacological blockade of KCa3.1 channel improved heart function and reduced ventricular dilation and fibrosis. Besides, a lower prevalence of myofibroblasts was found in TRAM-34 treatment group. In vitro studies KCa3.1 was up regulated in CFs induced by Ang II and suppressed by its blocker.KCa3.1 pharmacological blockade attenuated CFs proliferation, differentiation and profibrogenic genes expression and may regulating through AKT and ERK1/2 pathways. Conclusion: Blockade of KCa3.1 is able to attenuate ventricular remodeling after MI through inhibiting the pro-fibrotic effects of CFs.

  5. Krill oil attenuates left ventricular dilatation after myocardial infarction in rats.

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    Fosshaug, Linn E; Berge, Rolf K; Beitnes, Jan O; Berge, Kjetil; Vik, Hogne; Aukrust, Pål; Gullestad, Lars; Vinge, Leif E; Øie, Erik

    2011-12-29

    In the western world, heart failure (HF) is one of the most important causes of cardiovascular mortality. Supplement with n-3 polyunsaturated fatty acids (PUFA) has been shown to improve cardiac function in HF and to decrease mortality after myocardial infarction (MI). The molecular structure and composition of n-3 PUFA varies between different marine sources and this may be of importance for their biological effects. Krill oil, unlike fish oil supplements, contains the major part of the n-3 PUFA in the form of phospholipids. This study investigated effects of krill oil on cardiac remodeling after experimental MI. Rats were randomised to pre-treatment with krill oil or control feed 14 days before induction of MI. Seven days post-MI, the rats were examined with echocardiography and rats in the control group were further randomised to continued control feed or krill oil feed for 7 weeks before re-examination with echocardiography and euthanization. The echocardiographic evaluation showed significant attenuation of LV dilatation in the group pretreated with krill oil compared to controls. Attenuated heart weight, lung weight, and levels of mRNA encoding classical markers of LV stress, matrix remodeling and inflammation reflected these findings. The total composition of fatty acids were examined in the left ventricular (LV) tissue and all rats treated with krill oil showed a significantly higher proportion of n-3 PUFA in the LV tissue, although no difference was seen between the two krill oil groups. Supplement with krill oil leads to a proportional increase of n-3 PUFA in myocardial tissue and supplement given before induction of MI attenuates LV remodeling.

  6. Krill oil attenuates left ventricular dilatation after myocardial infarction in rats

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    Fosshaug Linn E

    2011-12-01

    Full Text Available Abstract Background In the western world, heart failure (HF is one of the most important causes of cardiovascular mortality. Supplement with n-3 polyunsaturated fatty acids (PUFA has been shown to improve cardiac function in HF and to decrease mortality after myocardial infarction (MI. The molecular structure and composition of n-3 PUFA varies between different marine sources and this may be of importance for their biological effects. Krill oil, unlike fish oil supplements, contains the major part of the n-3 PUFA in the form of phospholipids. This study investigated effects of krill oil on cardiac remodeling after experimental MI. Rats were randomised to pre-treatment with krill oil or control feed 14 days before induction of MI. Seven days post-MI, the rats were examined with echocardiography and rats in the control group were further randomised to continued control feed or krill oil feed for 7 weeks before re-examination with echocardiography and euthanization. Results The echocardiographic evaluation showed significant attenuation of LV dilatation in the group pretreated with krill oil compared to controls. Attenuated heart weight, lung weight, and levels of mRNA encoding classical markers of LV stress, matrix remodeling and inflammation reflected these findings. The total composition of fatty acids were examined in the left ventricular (LV tissue and all rats treated with krill oil showed a significantly higher proportion of n-3 PUFA in the LV tissue, although no difference was seen between the two krill oil groups. Conclusions Supplement with krill oil leads to a proportional increase of n-3 PUFA in myocardial tissue and supplement given before induction of MI attenuates LV remodeling.

  7. Early erythropoietin therapy attenuates remodeling and preserves function of left ventricle in porcine myocardial infarction.

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    Chua, Sarah; Leu, Steve; Lin, Yu-Chun; Sheu, Jiunn-Jye; Sun, Cheuk-Kwan; Chung, Sheng-Ying; Chai, Han-Tan; Lee, Fan-Yen; Kao, Ying-Hsien; Wu, Chiung-Jen; Chang, Li-Teh; Ko, Sheung-Fat; Yip, Hon-Kan

    2011-03-01

    Erythropoietin (EPO) has been shown to have anti-inflammatory, antiapoptotic, and proangiogenic effects. This study investigated whether early EPO treatment effectively preserves left ventricular (LV) function in porcine acute myocardial infarction (AMI). Eighteen male mini-pigs divided into groups 1 (sham), 2 (AMI), and 3 (AMI with 2 consecutive EPO doses [7500 IU per animal each time] at 30 minutes and 24 hours after AMI induction) underwent echocardiography before and 14 days after AMI induction through left anterior descending artery (LAD) ligation with myocardium harvested for analysis. Larger infarcted areas (IA) were noted in group 2 than in group 3. In both IA and peri-IA, percentage of apoptotic nuclei and CD40-positive cells, messenger RNA expressions of IL-8, matrix metalloproteinase-9, caspase-3, and Bcl-2 associated x protein were highest, whereas proliferator-activated receptor-γ coactivator-1α, endothelial nitric oxide synthase and Bcl-2 were lowest in group 2. Oxidative stress and cytosolic cytochrome c in IA were increased (P porcine AMI model effectively limits infarct size, attenuates LV remodeling, and preserves LV function.

  8. Effects of pacemaker, implantable cardioverter-defibrillator, and left ventricular leads on CT-based attenuation correction.

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    Suzuki, Akira; Koshida, Kichiro; Matsubara, Kosuke

    2014-03-01

    CT-based attenuation correction (CTAC) of myocardial SPECT images has been becoming more popular--and the application of SPECT/CT increasing--because it prevents attenuation-induced image degradation. However, CTAC can be affected by overestimation of counts caused by metals. It is possible that pacemaker, left ventricle (LV), and implantable cardioverter-defibrillator (ICD) leads have an influence on myocardial SPECT findings. The present study investigated the impact of these leads on SPECT with CTAC. Pacemaker, LV, and ICD leads were examined using a simple phantom and a cardiac phantom. The effects of metal artifacts from leads in high-resolution mode and ultra-high-resolution mode were assessed using a simple phantom. Images and polar maps were generated from the cardiac phantom. The pacemaker and LV leads essentially had no influence, whereas the ICD lead resulted in maximal (6%) overestimation in a study investigating which metals cause artifacts that affect CTAC. None of the leads seriously influenced CTAC when the cardiac phantom was used. Small pacemaker or ICD and LV leads will cause a slight overestimation, but CTAC should be used because it can correct attenuation of the inferior and anteroseptal walls on SPECT images.

  9. Early exercise training normalizes myofilament function and attenuates left ventricular pump dysfunction in mice with a large myocardial infarction.

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    de Waard, Monique C; van der Velden, Jolanda; Bito, Virginie; Ozdemir, Semir; Biesmans, Liesbeth; Boontje, Nicky M; Dekkers, Dick H W; Schoonderwoerd, Kees; Schuurbiers, Hans C H; de Crom, Rini; Stienen, Ger J M; Sipido, Karin R; Lamers, Jos M J; Duncker, Dirk J

    2007-04-13

    The extent and mechanism of the cardiac benefit of early exercise training following myocardial infarction (MI) is incompletely understood, but may involve blunting of abnormalities in Ca(2+)-handling and myofilament function. Consequently, we investigated the effects of 8-weeks of voluntary exercise, started early after a large MI, on left ventricular (LV) remodeling and dysfunction in the mouse. Exercise had no effect on survival, MI size or LV dimensions, but improved LV fractional shortening from 8+/-1 to 12+/-1%, and LVdP/dt(P30) from 5295+/-207 to 5794+/-207 mm Hg/s (both P<0.05), and reduced pulmonary congestion. These global effects of exercise were associated with normalization of the MI-induced increase in myofilament Ca(2+)-sensitivity (DeltapCa(50)=0.037). This effect of exercise was PKA-mediated and likely because of improved beta(1)-adrenergic signaling, as suggested by the increased beta(1)-adrenoceptor protein (48%) and cAMP levels (36%; all P<0.05). Exercise prevented the MI-induced decreased maximum force generating capacity of skinned cardiomyocytes (F(max) increased from 14.3+/-0.7 to 18.3+/-0.8 kN/m(2) P<0.05), which was associated with enhanced shortening of unloaded intact cardiomyocytes (from 4.1+/-0.3 to 7.0+/-0.6%; P<0.05). Furthermore, exercise reduced diastolic Ca(2+)-concentrations (by approximately 30%, P<0.05) despite the unchanged SERCA2a and PLB expression and PLB phosphorylation status. Importantly, exercise had no effect on Ca(2+)-transient amplitude, indicating that the improved LV and cardiomyocyte shortening were principally because of improved myofilament function. In conclusion, early exercise in mice after a large MI has no effect on LV remodeling, but attenuates global LV dysfunction. The latter can be explained by the exercise-induced improvement of myofilament function.

  10. Intra-coronary administration of cyclosporine limits infarct size, attenuates remodeling and preserves left ventricular function in porcine acute anterior infarction.

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    Sheu, Jiunn-Jye; Chua, Sarah; Sun, Cheuk-Kwan; Chang, Li-Teh; Yen, Chia-Hung; Wu, Chiung-Jen; Fu, Morgan; Yip, Hon-Kan

    2011-02-17

    We tested whether intra-coronary administration of cyclosporine effectively preserves left ventricular (LV) function in porcine acute anterior wall infarction (AMI). Eighteen male mini-pigs were randomized into groups 1 (control), 2 (AMI alone), and 3 (AMI with cyclosporine treatment). AMI was induced by ligating middle left anterior descending artery (LAD). Fifteen minutes after ligation, saline and cyclosporine (2.5 mg) combination was injected into LAD beyond ligation in groups 2 and 3, respectively. Echocardiography was performed after 14 days, followed by animal sacrifice. Larger infarcted area (IA) was noted in group 2 than in group 3 (p infarct size, attenuates LV remodeling and preserves LV function. Copyright © 2009. Published by Elsevier Ireland Ltd.

  11. Occupancy of serotonin transporters in the amygdala by paroxetine in association with attenuation of left amygdala activation by negative faces in major depressive disorder.

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    Ruhé, Henricus G; Koster, Michiel; Booij, Jan; van Herk, Marcel; Veltman, Dick J; Schene, Aart H

    2014-02-28

    Amygdala hyperactivation in major depressive disorder (MDD) might be attenuated by selective serotonin reuptake inhibitors (SSRIs), but the working mechanism remains unclear. We hypothesized that higher amygdala serotonin transporter (SERT) occupancy by paroxetine results in greater attenuation of amygdala activation by negative facial expressions in MDD patients. We treated fifteen MDD patients (22-55 years) with paroxetine 20-50mg/day. After 6 and 12 weeks, we quantified (1) clinical response (≥50% decrease in Hamilton Depression Rating Scale (HDRS), (2) SERT occupancy in both amygdala measured by repeated [123I]β-CIT single photon emission computed tomography (SPECT), and (3) amygdala activation when viewing fearful and angry (negative) faces with repeated functional MRI scans. Response rates were 4/15 and 9/15 at 6 and 12 weeks, respectively. Attenuation of left amygdala activation was associated with amygdala SERT occupancy (P=0.006) and response (P=0.015). This association may provide a rationale for decreased limbic activity seen during treatment of MDD. It might also explain the rapid decrease in negative attentional bias and amygdala activation caused by SSRIs. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  12. Effect of obesity reduction on preservation of heart function and attenuation of left ventricular remodeling, oxidative stress and inflammation in obese mice.

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    Wang, Hui-Ting; Liu, Chu-Feng; Tsai, Tzu-Hsien; Chen, Yung-Lung; Chang, Hsueh-Wen; Tsai, Ching-Yen; Leu, Steve; Zhen, Yen-Yi; Chai, Han-Tan; Chung, Sheng-Ying; Chua, Sarah; Yen, Chia-Hung; Yip, Hon-Kan

    2012-07-11

    Obesity is an important cardiovascular risk factor. This study tested the effect of obesity reduction on preserving left ventricular ejection fraction (LVEF) and attenuating inflammation, oxidative stress and LV remodeling in obese mice. Eight-week-old C57BL/6 J mice (n=24) were equally divided into control (fed a control diet for 22 weeks), obesity (high-fat diet, 22 weeks), and obese reduction (OR) (high-fat diet, 14 weeks; then control diet, 8 weeks). Animals were sacrificed at post 22-week high-fat diet and the LV myocardium collected. Heart weight, body weight, abdominal-fat weight, total cholesterol level and fasting blood glucose were higher in obesity than in control and OR (all pobesity than in control and OR (all pobesity as compared with control and OR (all pobesity than in control and OR (all pobesity.

  13. The Molecular Basis for Load-Induced Skeletal Muscle Hypertrophy

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    Marcotte, George R.; West, Daniel W.D.; Baar, Keith

    2016-01-01

    In a mature (weight neutral) animal, an increase in muscle mass only occurs when the muscle is loaded sufficiently to cause an increase in myofibrillar protein balance. A tight relationship between muscle hypertrophy, acute increases in protein balance, and the activity of the mechanistic target of rapamycin complex 1 (mTORC1) was demonstrated 15 years ago. Since then, our understanding of the signals that regulate load-induced hypertrophy has evolved considerably. For example, we now know that mechanical load activates mTORC1 in the same way as growth factors, by moving TSC2 (a primary inhibitor of mTORC1) away from its target (the mTORC activator) Rheb. However, the kinase that phosphorylates and moves TSC2 is different in the two processes. Similarly, we have learned that a distinct pathway exists whereby amino acids activate mTORC1 by moving it to Rheb. While mTORC1 remains at the forefront of load-induced hypertrophy, the importance of other pathways that regulate muscle mass are becoming clearer. Myostatin, is best known for its control of developmental muscle size. However, new mechanisms to explain how loading regulates this process are suggesting that it could play an important role in hypertrophic muscle growth as well. Lastly, new mechanisms are highlighted for how β2 receptor agonists could be involved in load-induced muscle growth and why these agents are being developed as non-exercise-based therapies for muscle atrophy. Overall, the results highlight how studying the mechanism of load-induced skeletal muscle mass is leading the development of pharmaceutical interventions to promote muscle growth in those unwilling or unable to perform resistance exercise. PMID:25359125

  14. Chronic treatment with metformin suppresses toll-like receptor 4 signaling and attenuates left ventricular dysfunction following myocardial infarction.

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    Soraya, Hamid; Clanachan, Alexander S; Rameshrad, Maryam; Maleki-Dizaji, Nasrin; Ghazi-Khansari, Mahmoud; Garjani, Alireza

    2014-08-15

    Acute treatment with metformin has a protective effect in myocardial infarction by suppression of inflammatory responses due to activation of AMP-activated protein kinase (AMPK). In the present study, the effect of chronic pre-treatment with metformin on cardiac dysfunction and toll-like receptor 4 (TLR4) activities following myocardial infarction and their relation with AMPK were assessed. Male Wistar rats were randomly assigned to one of 5 groups (n=6): normal control and groups were injected isoproterenol after chronic pre-treatment with 0, 25, 50, or 100mg/kg of metformin twice daily for 14 days. Isoproterenol (100mg/kg) was injected subcutaneously on the 13th and 14th days to induce acute myocardial infarction. Isoproterenol alone decreased left ventricular systolic pressure and myocardial contractility indexed as LVdp/dtmax and LVdp/dtmin. The left ventricular dysfunction was significantly lower in the groups treated with 25 and 50mg/kg of metformin. Metfromin markedly lowered isoproterenol-induced elevation in the levels of TLR4 mRNA, myeloid differentiation protein 88 (MyD88), tumor necrosis factor-alpha (TNF-α), and interleukin 6 (IL-6) in the heart tissues. Similar changes were also seen in the serum levels of TNF-α and IL-6. However, the lower doses of 25 and 50mg/kg were more effective than 100mg/kg. Phosphorylated AMPKα (p-AMPK) in the myocardium was significantly elevated by 25mg/kg of metformin, slightly by 50mg/kg, but not by 100mg/kg. Chronic pre-treatment with metformin reduces post-myocardial infarction cardiac dysfunction and suppresses inflammatory responses, possibly through inhibition of TLR4 activities. This mechanism can be considered as a target to protect infarcted myocardium. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Atorvastatin therapy during the peri-infarct period attenuates left ventricular dysfunction and remodeling after myocardial infarction.

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    Xian-Liang Tang

    Full Text Available Although statins impart a number of cardiovascular benefits, whether statin therapy during the peri-infarct period improves subsequent myocardial structure and function remains unclear. Thus, we evaluated the effects of atorvastatin on cardiac function, remodeling, fibrosis, and apoptosis after myocardial infarction (MI. Two groups of rats were subjected to permanent coronary occlusion. Group II (n = 14 received oral atorvastatin (10 mg/kg/d daily for 3 wk before and 4 wk after MI, while group I (n = 12 received equivalent doses of vehicle. Infarct size (Masson's trichrome-stained sections was similar in both groups. Compared with group I, echocardiographic left ventricular ejection fraction (LVEF and fractional area change (FAC were higher while LV end-diastolic volume (LVEDV and LV end-systolic and end-diastolic diameters (LVESD and LVEDD were lower in treated rats. Hemodynamically, atorvastatin-treated rats exhibited significantly higher dP/dt(max, end-systolic elastance (Ees, and preload recruitable stroke work (PRSW and lower LV end-diastolic pressure (LVEDP. Morphometrically, infarct wall thickness was greater in treated rats. The improvement of LV function by atorvastatin was associated with a decrease in hydroxyproline content and in the number of apoptotic cardiomyocyte nuclei. We conclude that atorvastatin therapy during the peri-infarct period significantly improves LV function and limits adverse LV remodeling following MI independent of a reduction in infarct size. These salubrious effects may be due in part to a decrease in myocardial fibrosis and apoptosis.

  16. Hydrogen gas attenuates embryonic gene expression and prevents left ventricular remodeling induced by intermittent hypoxia in cardiomyopathic hamsters.

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    Kato, Ryuji; Nomura, Atsuo; Sakamoto, Aiji; Yasuda, Yuki; Amatani, Koyuha; Nagai, Sayuri; Sen, Yoko; Ijiri, Yoshio; Okada, Yoshikatsu; Yamaguchi, Takehiro; Izumi, Yasukatsu; Yoshiyama, Minoru; Tanaka, Kazuhiko; Hayashi, Tetsuya

    2014-12-01

    The prevalence of sleep apnea is very high in patients with heart failure (HF). The aims of this study were to investigate the influence of intermittent hypoxia (IH) on the failing heart and to evaluate the antioxidant effect of hydrogen gas. Normal male Syrian hamsters (n = 22) and cardiomyopathic (CM) hamsters (n = 33) were exposed to IH (repeated cycles of 1.5 min of 5% oxygen and 5 min of 21% oxygen for 8 h during the daytime) or normoxia for 14 days. Hydrogen gas (3.05 vol/100 vol) was inhaled by some CM hamsters during hypoxia. IH increased the ratio of early diastolic mitral inflow velocity to mitral annulus velocity (E/e', 21.8 vs. 16.9) but did not affect the LV ejection fraction (EF) in normal Syrian hamsters. However, IH increased E/e' (29.4 vs. 21.5) and significantly decreased the EF (37.2 vs. 47.2%) in CM hamsters. IH also increased the cardiomyocyte cross-sectional area (672 vs. 443 μm(2)) and interstitial fibrosis (29.9 vs. 9.6%), along with elevation of oxidative stress and superoxide production in the left ventricular (LV) myocardium. Furthermore, IH significantly increased the expression of brain natriuretic peptide, β-myosin heavy chain, c-fos, and c-jun mRNA in CM hamsters. Hydrogen gas inhalation significantly decreased both oxidative stress and embryonic gene expression, thus preserving cardiac function in CM hamsters. In conclusion, IH accelerated LV remodeling in CM hamsters, at least partly by increasing oxidative stress in the failing heart. These findings might explain the poor prognosis of patients with HF and sleep apnea. Copyright © 2014 the American Physiological Society.

  17. Occupancy of serotonin transporters in the amygdala by paroxetine in association with attenuation of left amygdala activation by negative faces in major depressive disorder

    NARCIS (Netherlands)

    Ruhe, Henricus G.; Koster, Michiel; Booij, Jan; van Herk, Marcel; Veltman, Dick J.; Schene, Aart H.

    2014-01-01

    Amygdala hyperactivation in major depressive disorder (MDD) might be attenuated by selective serotonin reuptake inhibitors (SSRls), but the working mechanism remains unclear. We hypothesized that higher amygdala serotonin transporter (SERT) occupancy by paroxetine results in greater attenuation of

  18. Occupancy of serotonin transporters in the amygdala by paroxetine in association with attenuation of left amygdala activation by negative faces in major depressive disorder

    NARCIS (Netherlands)

    Ruhé, Henricus G.; Koster, Michiel; Booij, Jan; van Herk, Marcel; Veltman, Dick J.; Schene, Aart H.

    2014-01-01

    Amygdala hyperactivation in major depressive disorder (MDD) might be attenuated by selective serotonin reuptake inhibitors (SSRIs), but the working mechanism remains unclear. We hypothesized that higher amygdala serotonin transporter (SERT) occupancy by paroxetine results in greater attenuation of

  19. Influence of attenuation correction on transient left ventricular dilation in dual isotope myocardial perfusion imaging in patients with known or suspected coronary artery disease.

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    Brodov, Yafim; Frenkel, Alex; Chouraqui, Pierre; Przewloka, Kinga; Rispler, Shmuel; Abadi, Sobhi; Keidar, Zohar

    2012-07-01

    The aim of this study was to assess the effect of attenuation correction (AC) on left ventricular (LV) volumes and LV transient ischemic dilatation (TID) during dual-isotope single-photon emission computer tomographic (SPECT) myocardial perfusion imaging (MPI). Ninety-six patients (mean age 58 ± 11 years, 15% women, 38 patients completed exercise and 58 dipyridamole pharmacologic stress tests) assessed for known or suspected coronary artery disease underwent dual-isotope thallium-201 rest and technetium-99m sestamibi stress SPECT MPI with computed tomography-based AC. The TID ratio was calculated separately for non-AC and AC SPECT MPI studies as the ratio of the LV endocardial volume at stress divided by LV endocardial volume at rest. The mean and range of the gated LV ejection fraction during exercise and pharmacologic stress was 54 ± 12% (29% to 80%) and 58 ± 12% (27% to 80%), respectively. In the exercise stress group, the same mean LV endocardial volumes in non-AC and AC stress (76.4 ± 30 and 76.5 ± 28) and rest (66.3 ± 26 and 66.4 ± 24) studies were found (p = 0.90). There was no statistical difference between the mean exercise TID ratio in non-AC and AC studies (1.27 vs 1.31, respectively, p = 0.10). The same mean LV endocardial volumes in non-AC and AC in pharmacologic stress (79.9 ± 42 and 80 ± 41) and rest (71.4 ± 41 and 72.3 ± 37), respectively, were found (p = 0.50). There was no statistical difference between the mean dipyridamole TID ratio in non-AC and AC studies (1.20 vs 1.17, respectively, p = 0.10). In conclusion, LV volumes and TID indexes obtained on SPECT MPI with exercise or pharmacologic stress using dipyridamole are not affected by AC. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Numerical simulation of ice-load induced salt movements

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    Lang, Joerg; Al-Hseinat, Muayyad; Brandes, Christian; Hampel, Andrea; Hübscher, Christian; Winsemann, Jutta

    2015-04-01

    movement. The surface displacement due to ice-load induced salt movement will impact the pattern of glacigenic deformation, erosion and deposition. Ice-marginal uplift will provide favourable conditions for push-moraine formation, while subglacial subsidence of salt structures will enhance erosion and contribute to tunnel-valley incision. References Lang, J., Hampel, A., Brandes, C., Winsemann, J. (2014) Response of salt structures to ice-sheet loading: implications for ice-marginal and subglacial processes. Quaternary Science Reviews 101, 217-233. Liszkowski, J. (1993) The effects of Pleistocene ice-sheet loading-deloading cycles on the bedrock structure of Poland. Folia Quaternaria 64, 7-23.

  1. The influence of nodes sequence and extraneous load induced by graphical overviews on hypertext learning

    NARCIS (Netherlands)

    Bezdan, Eniko; Kester, Liesbeth; Kirschner, Paul A.

    2013-01-01

    Bezdan, E., Kester, L., & Kirschner, P. A. (2013). The influence of nodes sequence and extraneous load induced by graphical overviews on hypertext learning. Computers in Human Behavior, 29(3), 870-880.

  2. Autologous bone marrow cell implantation attenuates left ventricular remodeling and improves heart function in porcine myocardial infarction: an echocardiographic, six-month angiographic, and molecular-cellular study.

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    Leu, Steve; Sun, Cheuk-Kwan; Sheu, Jiunn-Jye; Chang, Li-Teh; Yuen, Chun-Man; Yen, Chia-Hung; Chiang, Chiang-Hua; Ko, Sheung-Fat; Pei, Sung-Nan; Chua, Sarah; Youssef, Ali A; Wu, Chiung-Jen; Yip, Hon-Kan

    2011-07-15

    We investigated the potential benefits and the underlying mechanisms of autologous bone marrow-derived mononuclear cell (BMDMNC) implantation in a porcine model of acute anterior wall myocardial infarction (AAWMI) by studying 6-month left ventricular (LV) function and LV remodeling. After being aspirated from the iliac crest and cultured for 1 week, BMDMNCs were implanted immediately after AAWMI induction through the left anterior descending artery ligation. Thirty male mini-pigs (16-18 kg) were equally divided into group 1 [AAWMI plus saline injection into infarct-ischemia area (IA)], group 2 (AAWMI plus 3.0 × 10⁷ BMDMNC transplantation into non-IA), group 3 (AAWMI plus 3.0 × 10⁷ BMDMNC transplantation into IA), group 4 (sham control plus 3.0 × 10⁷ BMDMNC transplantation into LV myocardium), and group 5 (normal control). By day 90, echocardiography demonstrated an increased LV end-diastolic and end-systolic dimensions but reduced LV ejection fraction (LVEF) in groups 1 and 2 than in other groups (all p infarct area, the number of small vessels and mRNA expressions of endothelial nitric oxide synthase, Bcl-2, interleukin (IL)-10, and peroxisome proliferator-activated receptor-γ coactivator-1α were lower, whereas the number of apoptotic nuclei, caspase-3, Bax, endothelin-1, IL-8, and matrix metalloproteinase was higher in groups 1 and 2 than in other groups (all p < 0.01). Autologous BMDMNC transplantation into IA rather non-IA improves LV function and reduces LV remodeling via eliciting a broad-spectrum of molecular-cellular defensive mechanisms. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  3. Load Induced Error Identification and Camber Curve Design of a Large-Span Crossbeam

    Directory of Open Access Journals (Sweden)

    Qiang Cheng

    2013-01-01

    Full Text Available Load induced errors aroused by internal masses of machine tool components and external cutting forces are a main contributor that influences machining accuracy. A mathematical model for load induced errors identification of large-span crossbeam in heavy-duty machine tool was proposed. According to the identified load induced errors, a method for optimisation of the guideway camber curve on crossbeam by particle swarm optimisation was proposed. Geometric errors of y-axis along cambered crossbeam and noncambered crossbeam were calibrated, and multibody system theory was also introduced to predict theoretically the machining accuracy of machine tool with two kinds of crossbeam. The comparisons between two kinds of crossbeam show that after cambering, the geometric errors are decreased and can meet the requirements of ISO standard, and the machining accuracy is enhanced remarkably too. In addition, the indirect dynamic straightness error of z-direction along cambered crossbeam was measured by displacement sensors, and the response results show that even though at the start-stop moment, the straightness error is also within the reasonable range of ISO standard.

  4. A functional insulin-like growth factor receptor is not necessary for load-induced skeletal muscle hypertrophy

    National Research Council Canada - National Science Library

    Espen E. Spangenburg; Derek Le Roith; Chris W. Ward; Sue C. Bodine

    2008-01-01

    ...-I), which is thought to be a critical step in the induction of muscle hypertrophy. To determine the role of the IGF-I receptor in load-induced skeletal muscle hypertrophy, we utilized a transgenic mouse model (MKR...

  5. Low rate loading-induced convection enhances net transport into the intervertebral disc in vivo.

    Science.gov (United States)

    Gullbrand, Sarah E; Peterson, Joshua; Mastropolo, Rosemarie; Roberts, Timothy T; Lawrence, James P; Glennon, Joseph C; DiRisio, Darryl J; Ledet, Eric H

    2015-05-01

    The intervertebral disc primarily relies on trans-endplate diffusion for the uptake of nutrients and the clearance of byproducts. In degenerative discs, diffusion is often diminished by endplate sclerosis and reduced proteoglycan content. Mechanical loading-induced convection has the potential to augment diffusion and enhance net transport into the disc. The ability of convection to augment disc transport is controversial and has not been demonstrated in vivo. To determine if loading-induced convection can enhance small molecule transport into the intervertebral disc in vivo. Net transport was quantified via postcontrast enhanced magnetic resonance imaging (MRI) into the discs of the New Zealand white rabbit lumbar spine subjected to in vivo cyclic low rate loading. Animals were administered the MRI contrast agent gadodiamide intravenously and subjected to in vivo low rate loading (0.5 Hz, 200 N) via a custom external loading apparatus for either 2.5, 5, 10, 15, or 20 minutes. Animals were then euthanized and the lumbar spines imaged using postcontrast enhanced MRI. The T1 constants in the nucleus, annulus, and cartilage endplates were quantified as a measure of gadodiamide transport into the loaded discs compared with the adjacent unloaded discs. Microcomputed tomography was used to quantify subchondral bone density. Low rate loading caused the rapid uptake and clearance of gadodiamide in the nucleus compared with unloaded discs, which exhibited a slower rate of uptake. Relative to unloaded discs, low rate loading caused a maximum increase in transport into the nucleus of 16.8% after 5 minutes of loading. Low rate loading increased the concentration of gadodiamide in the cartilage endplates at each time point compared with unloaded levels. Results from this study indicate that forced convection accelerated small molecule uptake and clearance in the disc induced by low rate mechanical loading. Low rate loading may, therefore, be therapeutic to the disc as it

  6. Comparison between a typical and a simplified model for blast load-induced structural response

    Science.gov (United States)

    Abd-Elhamed, A.; Mahmoud, S.

    2017-02-01

    As explosive blasts continue to cause severe damage as well as victims in both civil and military environments. There is a bad need for understanding the behavior of structural elements to such extremely short duration dynamic loads where it is of great concern nowadays. Due to the complexity of the typical blast pressure profile model and in order to reduce the modelling and computational efforts, the simplified triangle model for blast loads profile is used to analyze structural response. This simplified model considers only the positive phase and ignores the suction phase which characterizes the typical one in simulating blast loads. The closed from solution for the equation of motion under blast load as a forcing term modelled either typical or simplified models has been derived. The considered herein two approaches have been compared using the obtained results from simulation response analysis of a building structure under an applied blast load. The computed error in simulating response using the simplified model with respect to the typical one has been computed. In general, both simplified and typical models can perform the dynamic blast-load induced response of building structures. However, the simplified one shows a remarkably different response behavior as compared to the typical one despite its simplicity and the use of only positive phase for simulating the explosive loads. The prediction of the dynamic system responses using the simplified model is not satisfactory due to the obtained larger errors as compared to the system responses obtained using the typical one.

  7. Quantification of Crack Interaction in Loading-Induced Rock Deformation Tests

    Science.gov (United States)

    Reyes-Montes, J. M.; Goodfellow, S. D.; Nasseri, M. H.; Young, R.

    2013-12-01

    The coalescence of microcracks into major fractures marks the onset of major damage in rock and induces significant changes in its geotechnical and sealing properties. The interaction between neighbouring fractures affects the deformation process leading to this major failure. This study presents the analysis of load-induced fracture using spatial and temporal patterns of recorded acoustic emission (AE) events to investigate the role of crack interaction during fracturing processes Two methods based on event separation are used to estimate correlation and interaction distances between events. The first method uses the spacing of sequential and non-sequential event pairs, thus, the distance bin where both distributions converge can be interpreted as an upper bound for the interaction distance of correlated events in each of the experiments. The second method compares the distribution of inter-event separation of recorded events with the distribution obtained for a random population of events, quantifying the divergence between both distributions and its variation with time. A positive deviation for a distance range including up to the interaction distance observed in the previous approach indicates spatial clustering and process dominated by interactive events. This deviation is used to quantify the degree of event interaction or degree of non-randomness (NR) during the process. Two load-stress induced fracturing tests, carried out at two different scales, are analysed in this study to investigate the role of crack interaction in the deformation and fracturing process. The first test registered a total of 15,198 AE events from a pillar created between two deposition holes at SKB's Aspö Pillar Stability Experiment. The results show a good correlation between maxima of NR and minima in b-value in the time period immediately preceding and during the development of the observed major damage in form of spalling. The result can be interpreted as an indication of spalling

  8. Loading-Induced Reduction in Sclerostin as a Mechanism of Subchondral Bone Plate Sclerosis in Mouse Knee Joints During Late-Stage Osteoarthritis.

    Science.gov (United States)

    Jia, Haoruo; Ma, Xiaoyuan; Wei, Yulong; Tong, Wei; Tower, Robert J; Chandra, Abhishek; Wang, Luqiang; Sun, Zeyang; Yang, Zhaochun; Badar, Farid; Zhang, Kairui; Tseng, Wei-Ju; Kramer, Ina; Kneissel, Michaela; Xia, Yang; Liu, X Sherry; Wang, James H C; Han, Lin; Enomoto-Iwamoto, Motomi; Qin, Ling

    2018-02-01

    To establish an unbiased, 3-dimensional (3-D) approach that quantifies subchondral bone plate (SBP) changes in mouse joints, and to investigate the mechanism that mediates SBP sclerosis at a late stage of osteoarthritis (OA). A new micro-computed tomography (micro-CT) protocol was developed to characterize the entire thickness of the SBP in the distal femur of a normal mouse knee. Four mouse models of severe joint OA were generated: cartilage-specific Egfr-knockout (Egfr-CKO) mice at 2 months after surgical destabilization of the medial meniscus (DMM), Egfr-CKO mice with aging-related spontaneous OA, wild-type (WT) mice at 10 months after DMM, and WT mice at 14 weeks after DMM plus hemisectomy of the meniscus (DMMH) surgery. As an additional model, mice with knockout of the sclerostin gene (Sost-KO) were subjected to DMMH surgery. Knee joints were examined by micro-CT, histology, and immunohistochemical analyses. Examination of the mouse distal femur by 3-D micro-CT revealed a positive correlation between SBP thickness and the loading status in normal knees. In all 4 mouse models of late-stage OA, SBP sclerosis was restricted to the areas under severely eroded articular cartilage. This was accompanied by elevated bone formation at the bone marrow side of the SBP and a drastic reduction in the levels of sclerostin in osteocytes within the SBP. Unlike in WT mice, no further increase in the thickness of the SBP was observed in response to DMMH in Sost-KO mice. Since focal stress on the SBP underlying sites of cartilage damage increases during late stages of OA, these findings establish mechanical loading-induced attenuation of sclerostin expression and elevation of bone formation along the SBP surface as the major mechanisms characterizing subchondral bone phenotypes associated with severe late-stage OA in mice. © 2017, American College of Rheumatology.

  9. Heart Rate Reduction With Ivabradine Protects Against Left Ventricular Remodeling by Attenuating Infarct Expansion and Preserving Remote-Zone Contractile Function and Synchrony in a Mouse Model of Reperfused Myocardial Infarction.

    Science.gov (United States)

    O'Connor, Daniel M; Smith, Robert S; Piras, Bryan A; Beyers, Ronald J; Lin, Dan; Hossack, John A; French, Brent A

    2016-04-22

    Ivabradine selectively inhibits the pacemaker current of the sinoatrial node, slowing heart rate. Few studies have examined the effects of ivabradine on the mechanical properties of the heart after reperfused myocardial infarction (MI). Advances in ultrasound speckle-tracking allow strain analyses to be performed in small-animal models, enabling the assessment of regional mechanical function. After 1 hour of coronary occlusion followed by reperfusion, mice received 10 mg/kg per day of ivabradine dissolved in drinking water (n=10), or were treated as infarcted controls (n=9). Three-dimensional high-frequency echocardiography was performed at baseline and at days 2, 7, 14, and 28 post-MI. Speckle-tracking software was used to calculate intramural longitudinal myocardial strain (Ell) and strain rate. Standard deviation time to peak radial strain (SD Tpeak Err) and temporal uniformity of strain were calculated from short-axis cines acquired in the left ventricular remote zone. Ivabradine reduced heart rate by 8% to 16% over the course of 28 days compared to controls (Pleft ventricular remodeling and dyssynchrony, as well as improved mechanical performance in remote myocardium after heart rate reduction with ivabradine. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  10. Gravity loading induces adenosine triphosphate release and phosphorylation of extracellular signal-regulated kinases in human periodontal ligament cells.

    Science.gov (United States)

    Ito, Mai; Arakawa, Toshiya; Okayama, Miki; Shitara, Akiko; Mizoguchi, Itaru; Takuma, Taishin

    2014-11-01

    The periodontal ligament (PDL) receives mechanical stress (MS) from dental occlusion or orthodontic tooth movement. Mechanical stress is thought to be a trigger for remodeling of the PDL and alveolar bone, although its signaling mechanism is still unclear. So we investigated the effect of MS on adenosine triphosphate (ATP) release and extracellular signal-regulated kinases (ERK) phosphorylation in PDL cells. Mechanical stress was applied to human PDL cells as centrifugation-mediated gravity loading. Apyrase, Ca(2+)-free medium and purinergic receptor agonists and antagonists were utilized to analyze the contribution of purinergic receptors to ERK phosphorylation. Gravity loading and ATP increased ERK phosphorylation by 5 and 2.5 times, respectively. Gravity loading induced ATP release from PDL cells by tenfold. Apyrase and suramin diminished ERK phosphorylation induced by both gravity loading and ATP. Under Ca(2+)-free conditions the phosphorylation by gravity loading was partially decreased, whereas ATP-induced phosphorylation was unaffected. Receptors P2Y4 and P2Y6 were prominently expressed in the PDL cells. Gravity loading induced ATP release and ERK phosphorylation in PDL fibroblasts, and ATP signaling via P2Y receptors was partially involved in this phosphorylation, which in turn would enhance gene expression for the remodeling of PDL tissue during orthodontic tooth movement. © 2013 Wiley Publishing Asia Pty Ltd.

  11. Physical weight loading induces expression of tryptophan hydroxylase 2 in the brain stem.

    Directory of Open Access Journals (Sweden)

    Joon W Shim

    Full Text Available Sustaining brain serotonin is essential in mental health. Physical activities can attenuate mental problems by enhancing serotonin signaling. However, such activity is not always possible in disabled individuals or patients with dementia. Knee loading, a form of physical activity, has been found to mimic effects of voluntary exercise. Focusing on serotonergic signaling, we addressed a question: Does local mechanical loading to the skeleton elevate expression of tryptophan hydroxylase 2 (tph2 that is a rate-limiting enzyme for brain serotonin? A 5 min knee loading was applied to mice using 1 N force at 5 Hz for 1,500 cycles. A 5-min treadmill running was used as an exercise (positive control, and a 90-min tail suspension was used as a stress (negative control. Expression of tph2 was determined 30 min - 2 h in three brain regions --frontal cortex (FC, ventromedial hypothalamus (VMH, and brain stem (BS. We demonstrated for the first time that knee loading and treadmill exercise upregulated the mRNA level of tph2 in the BS, while tail suspension downregulated it. The protein level of tph2 in the BS was also upregulated by knee loading and downregulated by tail suspension. Furthermore, the downregulation of tph2 mRNA by tail suspension can be partially suppressed by pre-application of knee loading. The expression of tph2 in the FC and VMH was not significantly altered with knee loading. In this study we provided evidence that peripheral mechanical loading can activate central tph2 expression, suggesting that physical cues may mediate tph2-cathalyzed serotonergic signaling in the brain.

  12. Hypoplastic left heart syndrome

    Science.gov (United States)

    HLHS; Congenital heart - hypoplastic left heart; Cyanotic heart disease - hypoplastic left heart ... Hypoplastic left heart is a rare type of congenital heart disease. It is more common in males than in females. As ...

  13. Left axis deviation.

    Science.gov (United States)

    MacKenzie, Ross

    2005-01-01

    Left axis deviation is one of the most commonly encountered ECG abnormalities. Its presence should alert medical directors and underwriters to the possibility of underlying structural heart disease. Many of the causes of left axis deviation are apparent from the clinical findings. Left anterior fascicular block is one of the commonest causes of left axis deviation and has specific ECG criteria for its diagnosis.

  14. Pressure surge attenuator

    Science.gov (United States)

    Christie, Alan M.; Snyder, Kurt I.

    1985-01-01

    A pressure surge attenuation system for pipes having a fluted region opposite crushable metal foam. As adapted for nuclear reactor vessels and heads, crushable metal foam is disposed to attenuate pressure surges.

  15. Load Induced Blindness

    Science.gov (United States)

    Macdonald, James S. P.; Lavie, Nilli

    2008-01-01

    Although the perceptual load theory of attention has stimulated a great deal of research, evidence for the role of perceptual load in determining perception has typically relied on indirect measures that infer perception from distractor effects on reaction times or neural activity (see N. Lavie, 2005, for a review). Here we varied the level of…

  16. Quantifying load-induced solute transport and solute-matrix interaction within the osteocyte lacunar-canalicular system.

    Science.gov (United States)

    Wang, Bin; Zhou, Xiaozhou; Price, Christopher; Li, Wen; Pan, Jun; Wang, Liyun

    2013-05-01

    Osteocytes, the most abundant cells in bone, are essential in maintaining tissue homeostasis and orchestrating bone's mechanical adaptation. Osteocytes depend upon load-induced convection within the lacunar-canalicular system (LCS) to maintain viability and to sense their mechanical environment. Using the fluorescence recovery after photobleaching (FRAP) imaging approach, we previously quantified the convection of a small tracer (sodium fluorescein, 376 Da) in the murine tibial LCS under intermittent cyclic loading. In the present study, we first expanded the investigation of solute transport using a larger tracer (parvalbumin, 12.3 kDa), which is comparable in size to some signaling proteins secreted by osteocytes. Murine tibiae were subjected to sequential FRAP tests under rest-inserted cyclic loading while the loading magnitude (0, 2.8, or 4.8 N) and frequency (0.5, 1, or 2 Hz) were varied. The characteristic transport rate k and the transport enhancement relative to diffusion (k/k0) were measured under each loading condition, from which the peak solute velocity in the LCS was derived using our LCS transport model. Both the transport enhancement and solute velocity increased with loading magnitude and decreased with loading frequency. Furthermore, the solute-matrix interaction, quantified in terms of the reflection coefficient through the osteocytic pericellular matrix (PCM), was measured and theoretically modeled. The reflection coefficient of parvalbumin (σ = 0.084) was derived from the differential fluid and solute velocities within loaded bone. Using a newly developed PCM sieving model, the PCM's fiber configurations accounting for the measured interactions were obtained for the first time. The present study provided not only new data on the micro-fluidic environment experienced by osteocytes in situ but also a powerful quantitative tool for future study of the PCM, the critical interface that controls both outside-in and inside-out signaling in osteocytes

  17. QUANTIFYING LOAD-INDUCED SOLUTE TRANSPORT AND SOLUTE-MATRIX INTERACTIONS WITHIN THE OSTEOCYTE LACUNAR-CANALICULAR SYSTEM

    Science.gov (United States)

    Wang, Bin; Zhou, Xiaozhou; Price, Christopher; Li, Wen; Pan, Jun; Wang, Liyun

    2012-01-01

    Osteocytes, the most abundant cells in bone, are critical in maintaining tissue homeostasis and orchestrating bone’s mechanical adaptation. Osteocytes depend upon load-induced convection within the lacunar-canalicular system (LCS) to maintain viability and to sense their mechanical environment. Using the fluorescence recovery after photobleaching (FRAP) imaging approach, we previously quantified the convection of a small tracer (sodium fluorescein, 376Da) in the murine tibial LCS for an intermittent cyclic loading (Price et al., 2011. JBMR 26:277-85). In the present study we first expanded the investigation of solute transport using a larger tracer (parvalbumin, 12.3kDa), which is comparable in size to some signaling proteins secreted by osteocytes. Murine tibiae were subjected to sequential FRAP tests under rest-inserted cyclic loading while the loading magnitude (0, 2.8, or 4.8N) and frequency (0.5, 1, or 2 Hz) were varied. The characteristic transport rate k and the transport enhancement relative to diffusion (k/k0) were measured under each loading condition, from which the peak solute velocity in the LCS was derived using our LCS transport model. Both the transport enhancement and solute velocity increased with loading magnitude and decreased with loading frequency. Furthermore, the solute-matrix interactions, quantified in terms of the reflection coefficient through the osteocytic pericellular matrix (PCM), were measured and theoretically modeled. The reflection coefficient of parvalbumin (σ=0.084) was derived from the differential fluid and solute velocities within loaded bone. Using a newly developed PCM sieving model, the PCM’s fiber configurations accounting for the measured interactions were obtained for the first time. The present study provided not only new data on the micro-fluidic environment experienced by osteocytes in situ, but also a powerful quantitative tool for future study of the PCM, the critical interface that controls both outside

  18. Understanding left-handedness

    National Research Council Canada - National Science Library

    Gutwinski, Stefan; Löscher, Anna; Mahler, Lieselotte; Kalbitzer, Jan; Heinz, Andreas; Bermpohl, Felix

    2011-01-01

    .... In this article, we present these findings from a medical perspective. We selectively searched the PubMed online database for articles including the terms "handedness," "left handedness," "right handedness," and "cerebral lateralization...

  19. Left Ventricular Hypertrophy

    Science.gov (United States)

    ... need to restrict certain physical activities, such as weightlifting, which may temporarily raise your blood pressure. The ... Accessed April 6, 2015. Chatterjee S, et al. Meta-analysis of left ventricular hypertrophy and sustained arrhythmias. American ...

  20. Double inlet left ventricle

    Science.gov (United States)

    ... Univentricular heart; Univentricular heart of the left ventricular type; Congenital heart defect - DILV; ... BF, St. Geme JW, Schor NF. Cyanotic congenital heart disease. In: Kliegman RM, Stanton BF, St. Geme JW, ...

  1. Left heart catheterization

    Science.gov (United States)

    Catheterization - left heart ... to help guide the catheters up into your heart and arteries. Dye (sometimes called "contrast") will be ... in the blood vessels that lead to your heart. The catheter is then moved through the aortic ...

  2. Real-time measurement of solute transport within the lacunar-canalicular system of mechanically loaded bone: direct evidence for load-induced fluid flow.

    Science.gov (United States)

    Price, Christopher; Zhou, Xiaozhou; Li, Wen; Wang, Liyun

    2011-02-01

    Since proposed by Piekarski and Munro in 1977, load-induced fluid flow through the bone lacunar-canalicular system (LCS) has been accepted as critical for bone metabolism, mechanotransduction, and adaptation. However, direct unequivocal observation and quantification of load-induced fluid and solute convection through the LCS have been lacking due to technical difficulties. Using a novel experimental approach based on fluorescence recovery after photobleaching (FRAP) and synchronized mechanical loading and imaging, we successfully quantified the diffusive and convective transport of a small fluorescent tracer (sodium fluorescein, 376 Da) in the bone LCS of adult male C57BL/6J mice. We demonstrated that cyclic end-compression of the mouse tibia with a moderate loading magnitude (-3 N peak load or 400 µε surface strain at 0.5 Hz) and a 4-second rest/imaging window inserted between adjacent load cycles significantly enhanced (+31%) the transport of sodium fluorescein through the LCS compared with diffusion alone. Using an anatomically based three-compartment transport model, the peak canalicular fluid velocity in the loaded bone was predicted (60 µm/s), and the resulting peak shear stress at the osteocyte process membrane was estimated (∼5 Pa). This study convincingly demonstrated the presence of load-induced convection in mechanically loaded bone. The combined experimental and mathematical approach presented herein represents an important advance in quantifying the microfluidic environment experienced by osteocytes in situ and provides a foundation for further studying the mechanisms by which mechanical stimulation modulates osteocytic cellular responses, which will inform basic bone biology, clinical understanding of osteoporosis and bone loss, and the rational engineering of their treatments. Copyright © 2011 American Society for Bone and Mineral Research.

  3. Attenuation correction for the NIH ATLAS small animal PET scanner

    CERN Document Server

    Yao, Rutao; Liow, JeihSan; Seidel, Jurgen

    2003-01-01

    We evaluated two methods of attenuation correction for the NIH ATLAS small animal PET scanner: 1) a CT-based method that derives 511 keV attenuation coefficients (mu) by extrapolation from spatially registered CT images; and 2) an analytic method based on the body outline of emission images and an empirical mu. A specially fabricated attenuation calibration phantom with cylindrical inserts that mimic different body tissues was used to derive the relationship to convert CT values to (I for PET. The methods were applied to three test data sets: 1) a uniform cylinder phantom, 2) the attenuation calibration phantom, and 3) a mouse injected with left bracket **1**8F right bracket FDG. The CT-based attenuation correction factors were larger in non-uniform regions of the imaging subject, e.g. mouse head, than the analytic method. The two methods had similar correction factors for regions with uniform density and detectable emission source distributions.

  4. Landing gear noise attenuation

    Science.gov (United States)

    Moe, Jeffrey W. (Inventor); Whitmire, Julia (Inventor); Kwan, Hwa-Wan (Inventor); Abeysinghe, Amal (Inventor)

    2011-01-01

    A landing gear noise attenuator mitigates noise generated by airframe deployable landing gear. The noise attenuator can have a first position when the landing gear is in its deployed or down position, and a second position when the landing gear is in its up or stowed position. The noise attenuator may be an inflatable fairing that does not compromise limited space constraints associated with landing gear retraction and stowage. A truck fairing mounted under a truck beam can have a compliant edge to allow for non-destructive impingement of a deflected fire during certain conditions.

  5. Left-handedness and health

    National Research Council Canada - National Science Library

    Milenković, Sanja; Belojević, Goran; Kocijancić, Radojka

    2010-01-01

    .... There is no agreement between investigators who in fact may be considered a left-handed person, about the percentage of left-handers in the population and about the etiology of left-handedness...

  6. [Recurrent left atrial myxoma].

    Science.gov (United States)

    Moreno Martínez, Francisco L; Lagomasino Hidalgo, Alvaro; Mirabal Rodríguez, Roger; López Bermúdez, Félix H; López Bernal, Omaida J

    2003-01-01

    Primary cardiac tumors are rare. Mixomas are the most common among them; 75% are located in the left atrium, 20% in the right atrium, and the rest in the ventricles. The seldom appear in atrio-ventricular valves. Recidivant mixoma are also rare, appearing in 1-5% of all patients that have undergone surgical treatment of a mixoma. In this paper we present our experience with a female patient, who 8 years after having been operated of a left atrial mixoma, began with symptoms of mild heart failure. Transthoracic echocardiography revealed recurrence of the tumor, and was therefore subjected to a second open-heart surgery from which she recovered without complications.

  7. Left atrial appendage occlusion

    Directory of Open Access Journals (Sweden)

    Ahmad Mirdamadi

    2013-01-01

    Full Text Available Left atrial appendage (LAA occlusion is a treatment strategy to prevent blood clot formation in atrial appendage. Although, LAA occlusion usually was done by catheter-based techniques, especially percutaneous trans-luminal mitral commissurotomy (PTMC, it can be done during closed and open mitral valve commissurotomy (CMVC, OMVC and mitral valve replacement (MVR too. Nowadays, PTMC is performed as an optimal management of severe mitral stenosis (MS and many patients currently are treated by PTMC instead of previous surgical methods. One of the most important contraindications of PTMC is presence of clot in LAA. So, each patient who suffers of severe MS is evaluated by Trans-Esophageal Echocardiogram to rule out thrombus in LAA before PTMC. At open heart surgery, replacement of the mitral valve was performed for 49-year-old woman. Also, left atrial appendage occlusion was done during surgery. Immediately after surgery, echocardiography demonstrates an echo imitated the presence of a thrombus in left atrial appendage area, although there was not any evidence of thrombus in pre-pump TEE. We can conclude from this case report that when we suspect of thrombus of left atrial, we should obtain exact history of previous surgery of mitral valve to avoid misdiagnosis clotted LAA, instead of obliterated LAA. Consequently, it can prevent additional evaluations and treatments such as oral anticoagulation and exclusion or postponing surgeries including PTMC.

  8. The left minor fissure.

    Science.gov (United States)

    Austin, J H

    1986-11-01

    A left minor fissure (LMF) has been described anatomically as being present in 8%-18% of left lungs. Analogous to the right minor fissure (RMF), the LMF separates the anterior segment of the left upper lobe from the lingula. Two thousand consecutive normal radiographic examinations of the adult chest (posteroanterior, left lateral views with the subjects in the erect position) were reviewed prospectively. A definite LMF was identified in 32 of the subjects (1.6%). The fissure was dome-shaped (convex superior) on at least one projection in 26 (81%) of 32 subjects. The position of the LMF was usually more cephalad than that of the RMF (25 of 31 subjects, or 81%). The lateral end of the LMF was usually superior to the medial end (25 of 32; 78%) and rarely inferior to the medial end (three of 32; 9%). The LMF infrequently was horizontal (four of 32; 12%). In a number of additional patients whose control chest radiographs showed no evidence of an LMF, subsequent radiographs revealed an LMF outlined by active pulmonary or pleural disease.

  9. Left Ventricular Hypertrophy

    Science.gov (United States)

    ... AskMayoExpert. What tests are needed to confirm the diagnosis of hypertrophic cardiomyopathy (HCM) and what is the role of genetic testing? Rochester, Minn.: Mayo Foundation for Medical Education and Research; ... diagnosis in patients with hypertrophied left ventricles. Heart. 2014; ...

  10. Hypoplastic left heart syndrome

    Directory of Open Access Journals (Sweden)

    Thiagarajan Ravi

    2007-05-01

    Full Text Available Abstract Hypoplastic left heart syndrome(HLHS refers to the abnormal development of the left-sided cardiac structures, resulting in obstruction to blood flow from the left ventricular outflow tract. In addition, the syndrome includes underdevelopment of the left ventricle, aorta, and aortic arch, as well as mitral atresia or stenosis. HLHS has been reported to occur in approximately 0.016 to 0.036% of all live births. Newborn infants with the condition generally are born at full term and initially appear healthy. As the arterial duct closes, the systemic perfusion becomes decreased, resulting in hypoxemia, acidosis, and shock. Usually, no heart murmur, or a non-specific heart murmur, may be detected. The second heart sound is loud and single because of aortic atresia. Often the liver is enlarged secondary to congestive heart failure. The embryologic cause of the disease, as in the case of most congenital cardiac defects, is not fully known. The most useful diagnostic modality is the echocardiogram. The syndrome can be diagnosed by fetal echocardiography between 18 and 22 weeks of gestation. Differential diagnosis includes other left-sided obstructive lesions where the systemic circulation is dependent on ductal flow (critical aortic stenosis, coarctation of the aorta, interrupted aortic arch. Children with the syndrome require surgery as neonates, as they have duct-dependent systemic circulation. Currently, there are two major modalities, primary cardiac transplantation or a series of staged functionally univentricular palliations. The treatment chosen is dependent on the preference of the institution, its experience, and also preference. Although survival following initial surgical intervention has improved significantly over the last 20 years, significant mortality and morbidity are present for both surgical strategies. As a result pediatric cardiologists continue to be challenged by discussions with families regarding initial decision

  11. Maintenance of muscle mass and load-induced growth in Muscle RING Finger 1 null mice with age.

    Science.gov (United States)

    Hwee, Darren T; Baehr, Leslie M; Philp, Andrew; Baar, Keith; Bodine, Sue C

    2014-02-01

    Age-related loss of muscle mass occurs to varying degrees in all individuals and has a detrimental effect on morbidity and mortality. Muscle RING Finger 1 (MuRF1), a muscle-specific E3 ubiquitin ligase, is believed to mediate muscle atrophy through the ubiquitin proteasome system (UPS). Deletion of MuRF1 (KO) in mice attenuates the loss of muscle mass following denervation, disuse, and glucocorticoid treatment; however, its role in age-related muscle loss is unknown. In this study, skeletal muscle from male wild-type (WT) and MuRF1 KO mice was studied up to the age of 24 months. Muscle mass and fiber cross-sectional area decreased significantly with age in WT, but not in KO mice. In aged WT muscle, significant decreases in proteasome activities, especially 20S and 26S β5 (20-40% decrease), were measured and were associated with significant increases in the maladaptive endoplasmic reticulum (ER) stress marker, CHOP. Conversely, in aged MuRF1 KO mice, 20S or 26S β5 proteasome activity was maintained or decreased to a lesser extent than in WT mice, and no increase in CHOP expression was measured. Examination of the growth response of older (18 months) mice to functional overload revealed that old WT mice had significantly less growth relative to young mice (1.37- vs. 1.83-fold), whereas old MuRF1 KO mice had a normal growth response (1.74- vs. 1.90-fold). These data collectively suggest that with age, MuRF1 plays an important role in the control of skeletal muscle mass and growth capacity through the regulation of cellular stress. © 2013 the Anatomical Society and John Wiley & Sons Ltd.

  12. Left ventricular mural thrombus

    Energy Technology Data Exchange (ETDEWEB)

    Nixon, J.V.

    1983-08-01

    The identification of mural thrombus in patients with left ventricular aneurysm and mural thrombus probably warrants consideration of long-term anticoagulation. In patients with acute, large, anterior or anteroapical, transmural myocardial infarctions, serial noninvasive examinations are warranted to define a group of patients at high risk for the development of left ventricular aneurysm and/or mural thrombus. Anticoagulants should be considered in patients in whom mural thrombi develop as a complication of their infarction. Patients with congestive cardiomyopathy should be considered for long-term anticoagulation. These recommendations are all tempered by the realization that the use of anticoagulant therapy is not without its own risks. The decision to anticoagulate must be balanced against each individual patient's suitability for such therapy and the individual likelihood of the development of side effects.

  13. Radiofrequency attenuator and method

    Science.gov (United States)

    Warner, Benjamin P [Los Alamos, NM; McCleskey, T Mark [Los Alamos, NM; Burrell, Anthony K [Los Alamos, NM; Agrawal, Anoop [Tucson, AZ; Hall, Simon B [Palmerston North, NZ

    2009-01-20

    Radiofrequency attenuator and method. The attenuator includes a pair of transparent windows. A chamber between the windows is filled with molten salt. Preferred molten salts include quarternary ammonium cations and fluorine-containing anions such as tetrafluoroborate (BF.sub.4.sup.-), hexafluorophosphate (PF.sub.6.sup.-), hexafluoroarsenate (AsF.sub.6.sup.-), trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3C.sup.-). Radicals or radical cations may be added to or electrochemically generated in the molten salt to enhance the RF attenuation.

  14. Natural attenuation of herbicides

    DEFF Research Database (Denmark)

    Tuxen, Nina; Højberg, Anker Lajer; Broholm, Mette Martina

    2002-01-01

    A field injection experiment in a sandy, aerobic aquifer showed that two phenoxy acids MCPP (mecoprop) and dichlorprop were degraded within I in downgradient of the injection wells after an apparent lag period. The plume development and microbial measurements indicated that microbial growth....... The observations may be important for application of natural attenuation as a remedy in field scale systems....

  15. Left Ventricular Pseudoaneurysm Perceived as a Left Lung Mass

    Directory of Open Access Journals (Sweden)

    Ugur Gocen

    2013-02-01

    Full Text Available Left ventricular pseudo-aneurysm is a rare complication of aneurysmectomy. We present a case of surgically-treated left ventricular pseudo-aneurysm which was diagnosed three years after coronary artery bypass grafting and left ventricular aneurysmectomy. The presenting symptoms, diagnostic evaluation and surgical repair are described. [Cukurova Med J 2013; 38(1.000: 123-125

  16. CT imaging features and frequency of left ventricular myocardial fat in patients with CT findings of chronic left ventricular myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Zafar, H.M.; Litt, H.I. [Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, PA (United States); Torigian, D.A. [Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, PA (United States)], E-mail: drew.torigian@uphs.upenn.edu

    2008-03-15

    Aim: To determine the frequency of left ventricular myocardial fat in patients with computed tomography (CT) findings of chronic left ventricular myocardial infarction, and to review the typical CT imaging features. Materials and methods: A retrospective search of the CT and nuclear scintigraphy reports from 1998-2005 for chronic left ventricular myocardial infarction was performed. The study group comprised those cases with available CT examinations revealing findings of chronic left ventricular myocardial infarction. Assessment for the presence of various imaging characteristics of left ventricular myocardial fat was performed in all cases. Results: The frequency of left ventricular myocardial fat in 47 patients with CT evidence of chronic left ventricular myocardial infarction was 51%. Typical CT imaging features include thin linear or curvilinear fat attenuation within left ventricular myocardium, most commonly subendocardial, often associated with left ventricular wall thinning and/or calcification, predominantly in elderly men. Conclusions: Fat in the left ventricular myocardium is a common additional finding in patients with CT findings of chronic left ventricular myocardial infarction. The potential, but as yet unproven, use of this CT imaging finding is that the radiologist may be able to suggest a potential diagnosis of chronic left ventricular myocardial infarction on unenhanced, thick-section, non-gated or non-triggered chest CT imaging where identification of myocardial wall thinning may be difficult.

  17. Idiopathic Fascicular Left Ventricular Tachycardia.

    Science.gov (United States)

    Alahmad, Yaser; Asaad, Nidal Ahmad; Arafa, Salaheddin Omran; Ahmad Khan, Shahul Hameed; Mahmoud, Alsayed

    2017-01-01

    Idiopathic left fascicular ventricular tachycardia (ILFVT) is characterized by right bundle branch block morphology and left axis deviation. We report a case of idiopathic left ventricular fascicular tachycardia in a young 31-year-old male patient presenting with a narrow complex tachycardia.

  18. Idiopathic Fascicular Left Ventricular Tachycardia

    OpenAIRE

    Alahmad, Yaser; Asaad, Nidal Ahmad; Arafa, Salaheddin Omran; Ahmad Khan, Shahul Hameed; Mahmoud, Alsayed

    2017-01-01

    Idiopathic left fascicular ventricular tachycardia (ILFVT) is characterized by right bundle branch block morphology and left axis deviation. We report a case of idiopathic left ventricular fascicular tachycardia in a young 31-year-old male patient presenting with a narrow complex tachycardia.

  19. Fluid dynamic bowtie attenuators

    Science.gov (United States)

    Szczykutowicz, Timothy P.; Hermus, James

    2015-03-01

    Fluence field modulated CT allows for improvements in image quality and dose reduction. To date, only 1-D modulators have been proposed, the extension to 2-D modulation is difficult with solid-metal attenuation-based modulators. This work proposes to use liquids and gas to attenuate the x-ray beam which can be arrayed allowing for 2-D fluence modulation. The thickness of liquid and the pressure for a given path length of gas were determined that provided the same attenuation as 30 cm of soft tissue at 80, 100, 120, and 140 kV. Gaseous Xenon and liquid Iodine, Zinc Chloride, and Cerium Chloride were studied. Additionally, we performed some proof-of-concept experiments in which (1) a single cell of liquid was connected to a reservoir which allowed the liquid thickness to be modulated and (2) a 96 cell array was constructed in which the liquid thickness in each cell was adjusted manually. Liquid thickness varied as a function of kV and chemical composition, with Zinc Chloride allowing for the smallest thickness; 1.8, 2.25, 3, and 3.6 cm compensated for 30 cm of soft tissue at 80, 100, 120, and 140 kV respectively. The 96 cell Iodine attenuator allowed for a reduction in both dynamic range to the detector and scatter to primary ratio. Successful modulation of a single cell was performed at 0, 90, and 130 degrees using a simple piston/actuator. The thickness of liquids and the Xenon gas pressure seem logistically implementable within the constraints of CBCT and diagnostic CT systems.

  20. Arm folding, hand clasping, and Luria's concept of "latent left-handedness".

    Science.gov (United States)

    Mohr, Christine; Thut, Gregor; Landis, Theodor; Brugger, Peter

    2006-01-01

    Luria (1947/1970) proposed left-top positions in arm folding (AF) and hand clasping (HC) to be signs of "latent left-handedness". However, research since has revealed that (1) left-top positions are canonical for European right-handers and (2) combined AF/HC measures may provide more information about cerebral laterality than either measure considered alone. We tested whether AF and HC or AF/HC combinations predicted diminished right-handedness for 12 handedness items. Results from 509 healthy participants showed that (1) left-top positions in AF and HC were dominant across participants, as was right-handedness, and a right-top position in HC was associated with attenuated right-handedness, (2) right-hand preference was more frequently associated with congruent AF/HC combinations, especially of the LL type (AF: left-top / HC: left-top), and (3) non-right-hand preference was associated with non-congruent, predominantly LR combinations. We conjecture that the LL type combination indicates left hemispheric dominance for motor actions, whereas the LR combination, in which HC as the distally innervated posture deviates from the canonical pattern, indicates attenuated hemispheric asymmetry. Our data support Luria's proposition that a left-top preference in AF points to "latent" left-handedness, but only if associated with a right-top preference in HC. Consistent left-top preference for the combined AF/HC measure appears to predict right-handedness.

  1. [Left-handedness and health].

    Science.gov (United States)

    Milenković, Sanja; Belojević, Goran; Kocijancić, Radojka

    2010-01-01

    Hand dominance is defined as a proneness to use one hand rather than another in performing the majority of activities and this is the most obvious example of cerebral lateralization and an exclusive human characteristic. Left-handed people comprise 6-14% of the total population, while in Serbia, this percentage is 5-10%, moving from undeveloped to developed environments, where a socio-cultural pressure is less present. There is no agreement between investigators who in fact may be considered a left-handed person, about the percentage of left-handers in the population and about the etiology of left-handedness. In the scientific literature left-handedness has been related to health disorders (spine deformities, immunological disorders, migraine, neurosis, depressive psychosis, schizophrenia, insomnia, homosexuality, diabetes mellitus, arterial hypertension, sleep apnea, enuresis nocturna and Down Syndrome), developmental disorders (autism, dislexia and sttutering) and traumatism. The most reliable scientific evidences have been published about the relationship between left-handedness and spinal deformities in school children in puberty and with traumatism in general population. The controversy of other results in up-to-now investigations of health aspects of left-handedness may partly be explained by a scientific disagreement whether writing with the left hand is a sufficient criterium for left-handedness, or is it necessary to investigate other parameters for laterality assessment. Explanation of health aspects of left-handedness is dominantly based on Geschwind-Galaburda model about "anomalous" cerebral domination, as a consequence of hormonal disbalance.

  2. Understanding left-handedness.

    Science.gov (United States)

    Gutwinski, Stefan; Löscher, Anna; Mahler, Lieselotte; Kalbitzer, Jan; Heinz, Andreas; Bermpohl, Felix

    2011-12-01

    The human cerebrum is asymmetrical, consisting of two hemispheres with differing functions. Recent epidemiological and neurobiological research has shed new light on the development of the cerebral lateralization of motor processes, including handedness. In this article, we present these findings from a medical perspective. We selectively searched the PubMed online database for articles including the terms "handedness," "left handedness," "right handedness," and "cerebral lateralization." Highly ranked and commonly cited articles were included in our analysis. The emergence of handedness has been explained by physiological and pathological models. Handedness arose early in evolution and has probably been constitutive for the development of higher cognitive functions. For instance, handedness may have provided the basis for the development of speech and fine motor skills, both of which have played a critical role in the evolution of mankind. The disadvantages of certain types of handedness are discussed, as some cases seem to be associated with disease. The consideration of handedness from the epidemiological, neurobiological, and medical points of view provides insight into cerebral lateralization.

  3. Left ventricular noncompaction.

    Science.gov (United States)

    Ichida, Fukiko

    2009-01-01

    Left ventricular noncompaction (LVNC) is a recently defined cardiomyopathy characterized by a pattern of prominent trabecular meshwork and deep intertrabecular recesses, and is thought to be caused by arrest of normal endomyocardial morphogenesis. Although LVNC has been classified as a primary cardiomyopathy of genetic origin, its definition and diagnostic criteria are still being debated. Isolated LVNC was thought to be rare; however, heightened awareness has resulted in an increased detection of the morphological features of LVNC in routine clinical practice, especially in the adult population. Clinical manifestations are highly variable, ranging from no symptoms to disabling congestive heart failure, arrhythmias, and systemic thromboemboli. LVNC, like other forms of inherited cardiomyopathy, is genetically heterogeneous and can be inherited as an autosomal-dominant or X-linked recessive disorder. It has been linked to mutations in several genes, including LIM domain binding protein 3 (ZASP), alpha-dystrobrevin (DTNA), tafazzin (TAZ/G4.5) and those encoding sarcomeric proteins. However, the relatively small contribution of known mutations to the disease, compared with the higher proportion of familial cases suggests that other elusive genes remain to be identified.

  4. Characterizing the attenuation of coaxial and rectangular microwave-frequency waveguides at cryogenic temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Kurpiers, Philipp; Walter, Theodore; Magnard, Paul; Salathe, Yves; Wallraff, Andreas [ETH Zuerich, Department of Physics, Zuerich (Switzerland)

    2017-12-15

    Low-loss waveguides are required for quantum communication at distances beyond the chip-scale for any low-temperature solid-state implementation of quantum information processors. We measure and analyze the attenuation constant of commercially available microwave-frequency waveguides down to millikelvin temperatures and single photon levels. More specifically, we characterize the frequency-dependent loss of a range of coaxial and rectangular microwave waveguides down to 0.005 dB/m using a resonant-cavity technique. We study the loss tangent and relative permittivity of commonly used dielectric waveguide materials by measurements of the internal quality factors and their comparison with established loss models. The results of our characterization are relevant for accurately predicting the signal levels at the input of cryogenic devices, for reducing the loss in any detection chain, and for estimating the heat load induced by signal dissipation in cryogenic systems. (orig.)

  5. A Giant Left Atrial Myxoma

    Directory of Open Access Journals (Sweden)

    Medhat F. Zaher

    2014-01-01

    Full Text Available Atrial myxomas are the most common primary cardiac tumors. Patients with left atrial myxomas generally present with mechanical obstruction of blood flow, systemic embolization, and constitutional symptoms. We present a case of an unusually large left atrial myxoma discovered incidentally in a patient with longstanding dyspnea being managed as bronchial asthma.

  6. Myxoma of the Left Ventricle

    Science.gov (United States)

    Novoa, José; Delgado, Antonio; Alonso, Ana

    2014-01-01

    This report concerns a 69-year-old woman who presented with an asymptomatic myxoma in the left ventricle. The tumor was successfully excised. We provide a very brief review of 72 other published cases of surgically treated left ventricular myxoma. PMID:25120392

  7. Two Lefts in Latin America?

    DEFF Research Database (Denmark)

    Christensen, Steen Fryba

    In this working paper I list five researchers' categorizations of the Latin American left in power (april 2006) in a schematic form. The most important criteria for the categorizations are given.......In this working paper I list five researchers' categorizations of the Latin American left in power (april 2006) in a schematic form. The most important criteria for the categorizations are given....

  8. Left-handedness and health

    Directory of Open Access Journals (Sweden)

    Milenković Sanja

    2010-01-01

    Full Text Available Hand dominance is defined as a proneness to use one hand rather than another in performing the majority of activities and this is the most obvious example of cerebral lateralization and an exclusive human characteristic. Left-handed people comprise 6-14% of the total population, while in Serbia, this percentage is 5-10%, moving from undeveloped to developed environments, where a socio-cultural pressure is less present. There is no agreement between investigators who in fact may be considered a left-handed person, about the percentage of left-handers in the population and about the etiology of left-handedness. In the scientific literature left-handedness has been related to health disorders (spine deformities, immunological disorders, migraine, neurosis, depressive psychosis, schizophrenia, insomnia, homosexuality, diabetes mellitus, arterial hypertension, sleep apnea, enuresis nocturna and Down Syndrome, developmental disorders (autism, dislexia and sttutering and traumatism. The most reliable scientific evidences have been published about the relationship between left-handedness and spinal deformities in school children in puberty and with traumatism in general population. The controversy of other results in up-to-now investigations of health aspects of left-handedness may partly be explained by a scientific disagreement whether writing with the left hand is a sufficient criterium for left-handedness, or is it necessary to investigate other parameters for laterality assessment. Explanation of health aspects of left-handedness is dominantly based on Geschwind-Galaburda model about 'anomalous' cerebral domination, as a consequence of hormonal disbalance. .

  9. Left ventricular wall stress compendium.

    Science.gov (United States)

    Zhong, L; Ghista, D N; Tan, R S

    2012-01-01

    Left ventricular (LV) wall stress has intrigued scientists and cardiologists since the time of Lame and Laplace in 1800s. The left ventricle is an intriguing organ structure, whose intrinsic design enables it to fill and contract. The development of wall stress is intriguing to cardiologists and biomedical engineers. The role of left ventricle wall stress in cardiac perfusion and pumping as well as in cardiac pathophysiology is a relatively unexplored phenomenon. But even for us to assess this role, we first need accurate determination of in vivo wall stress. However, at this point, 150 years after Lame estimated left ventricle wall stress using the elasticity theory, we are still in the exploratory stage of (i) developing left ventricle models that properly represent left ventricle anatomy and physiology and (ii) obtaining data on left ventricle dynamics. In this paper, we are responding to the need for a comprehensive survey of left ventricle wall stress models, their mechanics, stress computation and results. We have provided herein a compendium of major type of wall stress models: thin-wall models based on the Laplace law, thick-wall shell models, elasticity theory model, thick-wall large deformation models and finite element models. We have compared the mean stress values of these models as well as the variation of stress across the wall. All of the thin-wall and thick-wall shell models are based on idealised ellipsoidal and spherical geometries. However, the elasticity model's shape can vary through the cycle, to simulate the more ellipsoidal shape of the left ventricle in the systolic phase. The finite element models have more representative geometries, but are generally based on animal data, which limits their medical relevance. This paper can enable readers to obtain a comprehensive perspective of left ventricle wall stress models, of how to employ them to determine wall stresses, and be cognizant of the assumptions involved in the use of specific models.

  10. Mode propagation and attenuation in lined ducts

    CERN Document Server

    BI, Wenping

    2014-01-01

    Optimal impedance for each mode is an important concept in an infinitely long duct lined with uniform absorption material. However it is not valid for finite length linings. This is because that the modes in lined ducts are not power-orthogonal; the total sound power is not equal to the sum of the sound power of each mode; cross-power terms may play important roles. In this paper, we study sound propagation and attenuation in an infinite rigid duct lined with a finite length of lining impedance. The lining impedance may be axial segments and circumferentially non-uniform. We propose two new physical quantities Kp and S to describe the self-overlap of the left eigenfunction and right eigenfunction of one mode and the normalized overlap between modes, respectively. The two new physical quantities describe totally the mode behaviors in lined ducts.

  11. Pentoxifylline Attenuates Cardiac Remodeling Induced by Tobacco Smoke Exposure

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-15

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

  12. Left bundle-branch block

    DEFF Research Database (Denmark)

    Risum, Niels; Strauss, David; Sogaard, Peter

    2013-01-01

    The relationship between myocardial electrical activation by electrocardiogram (ECG) and mechanical contraction by echocardiography in left bundle-branch block (LBBB) has never been clearly demonstrated. New strict criteria for LBBB based on a fundamental understanding of physiology have recently...

  13. Right colon cancer: Left behind.

    Science.gov (United States)

    Gervaz, P; Usel, M; Rapiti, E; Chappuis, P; Neyroud-Kaspar, I; Bouchardy, C

    2016-09-01

    Prognosis of colon cancer (CC) has steadily improved during the past three decades. This trend, however, may vary according to proximal (right) or distal (left) tumor location. We studied if improvement in survival was greater for left than for right CC. We included all CC recorded at the Geneva population-based registry between 1980 and 2006. We compared patients, tumor and treatment characteristics between left and right CC by logistic regression and compared CC specific survival by Cox models taking into account putative confounders. We also compared changes in survival between CC location in early and late years of observation. Among the 3396 CC patients, 1334 (39%) had right-sided and 2062 (61%) left-sided tumors. In the early 1980s, 5-year specific survival was identical for right and left CCs (49% vs. 48%). During the study period, a dramatic improvement in survival was observed for patients with left-sided cancers (Hazard ratio [HR]: 0.42, 95% confidence interval [CI]: 0.29-0.62, p colon cancer patients, those with right-sided lesions have by far the worse prognosis. Change of strategic management in this subgroup is warranted. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. SEISMIC ATTENUATION FOR RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Joel Walls; M.T. Taner; Gary Mavko; Jack Dvorkin

    2002-04-01

    Wave-induced variations of pore pressure in a partially-saturated reservoir result in oscillatory liquid flow. The viscous losses during this flow are responsible for wave attenuation. The same viscous effects determine the changes in the dynamic bulk modulus of the system versus frequency. These changes are necessarily linked to attenuation via the causality condition. We analytically quantify the frequency dependence of the bulk modulus of a partially saturated rock by assuming that saturation is patchy and then link these changes to the inverse quality factor. As a result, the P-wave attenuation is quantitatively linked to saturation and thus can serve as a saturation indicator.

  15. Integrated Microfluidic Variable Optical Attenuator

    Science.gov (United States)

    2005-11-28

    indices , the optical output power is gradually attenuated. We obtain a maximum attenuation of 28 dB when the fluid refractive index changes from 1.557 to...Electron. 23, pp. 1348-1354 (2005). 14. J. M. Ruano, V. Benoit, J. S. Aitchison , and J. M. Cooper, “Flame hydrolysis deposition of glass on silicon for...different refractive indices flowing in a microfluidic channel as the cladding for a segment of straight optical waveguide. Recently, the integration of

  16. Producing The New Regressive Left

    DEFF Research Database (Denmark)

    Crone, Christine

    to be a committed artist, and how that translates into supporting al-Assad’s rule in Syria; the Ramadan programme Harrir Aqlak’s attempt to relaunch an intellectual renaissance and to promote religious pluralism; and finally, al-Mayadeen’s cooperation with the pan-Latin American TV station TeleSur and its ambitions...... becomes clear from the analytical chapters is the emergence of the new cross-ideological alliance of The New Regressive Left. This emerging coalition between Shia Muslims, religious minorities, parts of the Arab Left, secular cultural producers, and the remnants of the political,strategic resistance...

  17. AVE 0991 attenuates cardiac hypertrophy through reducing oxidative stress.

    Science.gov (United States)

    Ma, Yuedong; Huang, Huiling; Jiang, Jingzhou; Wu, Lingling; Lin, Chunxi; Tang, Anli; Dai, Gang; He, Jiangui; Chen, Yili

    2016-06-10

    AVE 0991, the nonpeptide angiotensin-(1-7) (Ang-(1-7)) analog, is recognized as having beneficial cardiovascular effects. However, the mechanisms have not been fully elucidated. This study was designed to investigate the effects of AVE 0991 on cardiac hypertrophy and the mechanisms involved. Mice were underwent aortic banding to induce cardiac hypertrophy followed by the administration of AVE 0991 (20 mg kg·day (-1)) for 4 weeks. It was shown that AVE 0991 reduced left ventricular hypertrophy and improved heart function, characterized by decreases in left ventricular weight and left ventricular end-diastolic diameter, and increases in ejection fraction. Moreover, AVE 0991 significantly down-regulated mean myocyte diameter and attenuate the gene expression of the hypertrophic markers. Furthermore, AVE 0991 inhibited the expression of NOX 2 and NOX 4, meaning that AVE 0991 reduced oxidative stress of cardiac hypertrophy mice. Our data showed that AVE 0991 treatment could attenuate cardiac hypertrophy and improve heart function, which may be due to reduce oxidative stress. Copyright © 2016. Published by Elsevier Inc.

  18. On Wave-Ice Interaction in the Arctic Marginal Ice Zone: Dispersion, Attenuation, and Ice Response

    Science.gov (United States)

    2016-06-01

    attention is given to formulations of the dispersion relation. The dispersion relation determines the wave attenuation for non- conservative dissipation...41 4.3 FINAL THOUGHTS ...2.0 M, AND 3.5 M ARE SHOWN FROM LEFT TO RIGHT , TOP TO BOTTOM. THE SHEAR MODULUS RANGES FROM 1 PA (DARK BLUE) TO 1010 PA (DARK RED) WITH

  19. Attenuation in Superconducting Circular Waveguides

    Directory of Open Access Journals (Sweden)

    K. H. Yeap

    2016-09-01

    Full Text Available We present an analysis on wave propagation in superconducting circular waveguides. In order to account for the presence of quasiparticles in the intragap states of a superconductor, we employ the characteristic equation derived from the extended Mattis-Bardeen theory to compute the values of the complex conductivity. To calculate the attenuation in a circular waveguide, the tangential fields at the boundary of the wall are first matched with the electrical properties (which includes the complex conductivity of the wall material. The matching of fields with the electrical properties results in a set of transcendental equations which is able to accurately describe the propagation constant of the fields. Our results show that although the attenuation in the superconducting waveguide above cutoff (but below the gap frequency is finite, it is considerably lower than that in a normal waveguide. Above the gap frequency, however, the attenuation in the superconducting waveguide increases sharply. The attenuation eventually surpasses that in a normal waveguide. As frequency increases above the gap frequency, Cooper pairs break into quasiparticles. Hence, we attribute the sharp rise in attenuation to the increase in random collision of the quasiparticles with the lattice structure.

  20. Backscatter and attenuation characterization of ventricular myocardium

    Science.gov (United States)

    Gibson, Allyson Ann

    2009-12-01

    This Dissertation presents quantitative ultrasonic measurements of the myocardium in fetal hearts and adult human hearts with the goal of studying the physics of sound waves incident upon anisotropic and inhomogeneous materials. Ultrasound has been used as a clinical tool to assess heart structure and function for several decades. The clinical usefulness of this noninvasive approach has grown with our understanding of the physical mechanisms underlying the interaction of ultrasonic waves with the myocardium. In this Dissertation, integrated backscatter and attenuation analyses were performed on midgestational fetal hearts to assess potential differences in the left and right ventricular myocardium. The hearts were interrogated using a 50 MHz transducer that enabled finer spatial resolution than could be achieved at more typical clinical frequencies. Ultrasonic data analyses demonstrated different patterns and relative levels of backscatter and attenuation from the myocardium of the left ventricle and the right ventricle. Ultrasonic data of adult human hearts were acquired with a clinical imaging system and quantified by their magnitude and time delay of cyclic variation of myocardial backscatter. The results were analyzing using Bayes Classification and ROC analysis to quantify potential advantages of using a combination of two features of cyclic variation of myocardial backscatter over using only one or the other feature to distinguish between groups of subjects. When the subjects were classified based on hemoglobin A1c, the homeostasis model assessment of insulin resistance, and the ratio of triglyceride to high-density lipoprotein-cholesterol, differences in the magnitude and normalized time delay of cyclic variation of myocardial backscatter were observed. The cyclic variation results also suggested a trend toward a larger area under the ROC curve when information from magnitude and time delay of cyclic variation is combined using Bayes classification than when

  1. Paired associative stimulation of left and right human motor cortex shapes interhemispheric motor inhibition based on a Hebbian mechanism.

    Science.gov (United States)

    Rizzo, V; Siebner, H S; Morgante, F; Mastroeni, C; Girlanda, P; Quartarone, A

    2009-04-01

    This study was designed to examine whether corticocortical paired associative stimulation (cc-PAS) can modulate interhemispheric inhibition (IHI) in the human brain. Twelve healthy right-handed volunteers received 90 paired transcranial stimuli to the right and left primary motor hand area (M1(HAND)) at an interstimulus interval (ISI) of 8 ms. Left-to-right cc-PAS (first pulse given to left M1(HAND)) attenuated left-to-right IHI for one hour after cc-PAS. Left-to-right cc-PAS also increased corticospinal excitability in the conditioned right M1(HAND). These effects were not seen in an asymptomatic individual with callosal agenesis. Additional experiments showed no changes in left-to-right IHI or corticospinal excitability when left-to-right cc-PAS was given at an ISI of 1 ms or at multiple ISIs in random order. At the behavioral level, left-to-right cc-PAS speeded responses with the left but not right index finger during a simple reaction time task. Right-to-left cc-PAS (first pulse given to right M1(HAND)) reduced right-to-left IHI without increasing corticospinal excitability in left M1(HAND). These results provide a proof of principle that cc-PAS can induce associative plasticity in connections between the targeted cortical areas. The efficacy of cc-PAS to induce lasting changes in excitability depends on the exact timing of the stimulus pairs suggesting an underlying Hebbian mechanism.

  2. What Research Tells Us About Left Handedness.

    Science.gov (United States)

    Arnold, Rita

    Left handed people have had bad publicity throughout history, and the resulting myths and disadvantages of left handedness have often not been properly dealt with in the classroom. Our language itself maintains a bias against the left, and many other cultures have defined the left as disreputable. Today's life style also provides many physical…

  3. Left Activism, Succour and Selfhood

    DEFF Research Database (Denmark)

    Hughes, Celia Penelope

    2014-01-01

    At the height of mass activity on the Left, the ascendancy of the women's liberation movement (WLM), and the beginnings of real social and personal change for men and women, the 1970s are increasingly seen as the decade when sixties permissiveness began to be truly felt in Britain. This article...... draws upon a personal archive of correspondence from this turbulent decade, between two revolutionary women, Di Parkin and Annie Howells. It argues that the women's letters form an important contribution to new understandings about the construction of the post-war gendered self. The letters represent...... an interchange of motherhood, domesticity, far-left politics, and close female friendship. The article will show how the women's epistolary friendship offers intimate insight into female self-fashioning at a breakthrough social and political moment in 1970s Britain. As they reflected on some of the key political...

  4. Attenuation in silica-based optical fibers

    DEFF Research Database (Denmark)

    Wandel, Marie Emilie

    2006-01-01

    In this thesis on attenuation in silica based optical fibers results within three main topics are reported. Spectral attenuation measurements on transmission fibers are performed in the wide wavelength range 290 nm – 1700 nm. The measured spectral attenuation is analyzed with special emphasis...... on absorption peaks in order to investigate the cause of an unusual high attenuation in a series of transmission fibers. Strong indications point to Ni2+ in octahedral coordination as being the cause of the high attenuation. The attenuation of fibers having a high core refractive index is analyzed and the cause...... of the high attenuation measured in such fibers is described as being due to scattering of light on fluctuations of the core diameter. A novel semi-empirical model for predicting the attenuation of high index fibers is presented. The model is shown to be able to predict the attenuation of high index fibers...

  5. Left-handedness and health

    OpenAIRE

    Milenković Sanja; Belojević Goran; Kocijančić Radojka

    2010-01-01

    Hand dominance is defined as a proneness to use one hand rather than another in performing the majority of activities and this is the most obvious example of cerebral lateralization and an exclusive human characteristic. Left-handed people comprise 6-14% of the total population, while in Serbia, this percentage is 5-10%, moving from undeveloped to developed environments, where a socio-cultural pressure is less present. There is no agreement between investigators who in fact may be considered ...

  6. Antiandrogenic therapy with finasteride attenuates cardiac hypertrophy and left ventricular dysfunction.

    Science.gov (United States)

    Zwadlo, Carolin; Schmidtmann, Elisa; Szaroszyk, Malgorzata; Kattih, Badder; Froese, Natali; Hinz, Hebke; Schmitto, Jan Dieter; Widder, Julian; Batkai, Sandor; Bähre, Heike; Kaever, Volkhard; Thum, Thomas; Bauersachs, Johann; Heineke, Joerg

    2015-03-24

    In comparison with men, women have a better prognosis when experiencing aortic valve stenosis, hypertrophic cardiomyopathy, or heart failure. Recent data suggest that androgens like testosterone or the more potent dihydrotestosterone contribute to the development of cardiac hypertrophy and failure. Therefore, we analyzed whether antiandrogenic therapy with finasteride, which inhibits the generation of dihydrotestosterone by the enzyme 5-α-reductase, improves pathological ventricular remodeling and heart failure. We found a strongly induced expression of all 3 isoforms of the 5-α-reductase (Srd5a1 to Srd5a3) in human and mouse hearts with pathological hypertrophy, which was associated with increased myocardial accumulation of dihydrotestosterone. Starting 1 week after the induction of pressure overload by transaortic constriction, mice were treated with finasteride for 2 weeks. Cardiac function, hypertrophy, dilation, and fibrosis were markedly improved in response to finasteride treatment in not only male, but also in female mice. In addition, finasteride also very effectively improved cardiac function and mortality after long-term pressure overload and prevented disease progression in cardiomyopathic mice with myocardial Gαq overexpression. Mechanistically, finasteride, by decreasing dihydrotestosterone, potently inhibited hypertrophy and Akt-dependent prohypertrophic signaling in isolated cardiac myocytes, whereas the introduction of constitutively active Akt blunted these effects of finasteride. Finasteride, which is currently used in patients to treat prostate disease, potently reverses pathological cardiac hypertrophy and dysfunction in mice and might be a therapeutic option for heart failure. © 2015 American Heart Association, Inc.

  7. Krill oil attenuates left ventricular dilatation after myocardial infarction in rats

    OpenAIRE

    Fosshaug Linn E; Berge Rolf K; Beitnes Jan O; Berge Kjetil; Vik Hogne; Aukrust Pål; Gullestad Lars; Vinge Leif E; Øie Erik

    2011-01-01

    Background In the western world, heart failure (HF) is one of the most important causes of cardiovascular mortality. Supplement with n-3 polyunsaturated fatty acids (PUFA) has been shown to improve cardiac function in HF and to decrease mortality after myocardial infarction (MI). The molecular structure and composition of n-3 PUFA varies between different marine sources and this may be of importance for their biological effects. Krill oil, unlike fish oil supplements, conta...

  8. Seismic attenuation imaging with causality

    NARCIS (Netherlands)

    Hak, B.; Mulder, W.A.

    2010-01-01

    Seismic data enable imaging of the Earth, not only of velocity and density but also of attenuation contrasts. Unfortunately, the Born approximation of the constant-density visco-acoustic wave equation, which can serve as a forward modelling operator related to seismic migration, exhibits an

  9. Josephson tunnel junction microwave attenuator

    DEFF Research Database (Denmark)

    Koshelets, V. P.; Shitov, S. V.; Shchukin, A. V.

    1993-01-01

    A new element for superconducting electronic circuitry-a variable attenuator-has been proposed, designed, and successfully tested. The principle of operation is based on the change in the microwave impedance of a superconductor-insulator-superconductor (SIS) Josephson tunnel junction when dc bias...

  10. Compact plasmonic variable optical attenuator

    DEFF Research Database (Denmark)

    Leosson, Kristjan; Rosenzveig, Tiberiu; Hermannsson, Pétur Gordon

    2008-01-01

    We demonstrate plasmonic nanowire-based thermo-optic variable optical attenuators operating in the 1525-1625 nm wavelength range. The devices have a footprint as low as 1 mm, extinction ratio exceeding 40 dB, driving voltage below 3 V, and full modulation bandwidth of 1 kHz. The polarization...

  11. Flagella overexpression attenuates Salmonella pathogenesis.

    Directory of Open Access Journals (Sweden)

    Xinghong Yang

    Full Text Available Flagella are cell surface appendages involved in a number of bacterial behaviors, such as motility, biofilm formation, and chemotaxis. Despite these important functions, flagella can pose a liability to a bacterium when serving as potent immunogens resulting in the stimulation of the innate and adaptive immune systems. Previous work showing appendage overexpression, referred to as attenuating gene expression (AGE, was found to enfeeble wild-type Salmonella. Thus, this approach was adapted to discern whether flagella overexpression could induce similar attenuation. To test its feasibility, flagellar filament subunit FliC and flagellar regulon master regulator FlhDC were overexpressed in Salmonella enterica serovar Typhimurium wild-type strain H71. The results show that the expression of either FliC or FlhDC alone, and co-expression of the two, significantly attenuates Salmonella. The flagellated bacilli were unable to replicate within macrophages and thus were not lethal to mice. In-depth investigation suggests that flagellum-mediated AGE was due to the disruptive effects of flagella on the bacterial membrane, resulting in heightened susceptibilities to hydrogen peroxide and bile. Furthermore, flagellum-attenuated Salmonella elicited elevated immune responses to Salmonella presumably via FliC's adjuvant effect and conferred robust protection against wild-type Salmonella challenge.

  12. Flagella Overexpression Attenuates Salmonella Pathogenesis

    Science.gov (United States)

    Yang, Xinghong; Thornburg, Theresa; Suo, Zhiyong; Jun, SangMu; Robison, Amanda; Li, Jinquan; Lim, Timothy; Cao, Ling; Hoyt, Teri; Avci, Recep; Pascual, David W.

    2012-01-01

    Flagella are cell surface appendages involved in a number of bacterial behaviors, such as motility, biofilm formation, and chemotaxis. Despite these important functions, flagella can pose a liability to a bacterium when serving as potent immunogens resulting in the stimulation of the innate and adaptive immune systems. Previous work showing appendage overexpression, referred to as attenuating gene expression (AGE), was found to enfeeble wild-type Salmonella. Thus, this approach was adapted to discern whether flagella overexpression could induce similar attenuation. To test its feasibility, flagellar filament subunit FliC and flagellar regulon master regulator FlhDC were overexpressed in Salmonella enterica serovar Typhimurium wild-type strain H71. The results show that the expression of either FliC or FlhDC alone, and co-expression of the two, significantly attenuates Salmonella. The flagellated bacilli were unable to replicate within macrophages and thus were not lethal to mice. In-depth investigation suggests that flagellum-mediated AGE was due to the disruptive effects of flagella on the bacterial membrane, resulting in heightened susceptibilities to hydrogen peroxide and bile. Furthermore, flagellum-attenuated Salmonella elicited elevated immune responses to Salmonella presumably via FliC’s adjuvant effect and conferred robust protection against wild-type Salmonella challenge. PMID:23056473

  13. Systolic left ventricular function according to left ventricular concentricity and dilatation in hypertensive patients

    DEFF Research Database (Denmark)

    Bang, Casper; Gerdts, Eva; Aurigemma, Gerard P

    2013-01-01

    Left ventricular hypertrophy [LVH, high left ventricular mass (LVM)] is traditionally classified as concentric or eccentric based on left ventricular relative wall thickness. We evaluated left ventricular systolic function in a new four-group LVH classification based on left ventricular dilatatio...

  14. Mechanisms of geometrical seismic attenuation

    Directory of Open Access Journals (Sweden)

    Igor B. Morozov

    2011-07-01

    Full Text Available In several recent reports, we have explained the frequency dependence of the apparent seismic quality-factor (Q observed in many studies according to the effects of geometrical attenuation, which was defined as the zero-frequency limit of the temporal attenuation coefficient. In particular, geometrical attenuation was found to be positive for most waves traveling within the lithosphere. Here, we present three theoretical models that illustrate the origin of this geometrical attenuation, and we investigate the causes of its preferential positive values. In addition, we discuss the physical basis and limitations of both the conventional and new attenuation models. For waves in media with slowly varying properties, geometrical attenuation is caused by variations in the wavefront curvature, which can be both positive (for defocusing and negative (for focusing. In media with velocity/density contrasts, incoherent reflectivity leads to geometrical-attenuation coefficients which are proportional to the mean squared reflectivity and are always positive. For «coherent» reflectivity, the geometrical attenuation is approximately zero, and the attenuation process can be described according to the concept of «scattering Q». However, the true meaning of this parameter is in describing the mean reflectivity within the medium, and not that of the traditional resonator quality factor known in mechanics. The general conclusion from these models is that non-zero and often positive levels of geometrical attenuation are common in realistic, heterogeneous media, both observationally and theoretically. When transformed into the conventional Q-factor form, this positive geometrical attenuation leads to Q values that quickly increase with frequency. These predictions show that the positive frequency-dependent Q observed in many datasets might represent artifacts of the transformations of the attenuation coefficients into Q.

  1. Effect of the direct renin inhibitor aliskiren on left ventricular remodelling following myocardial infarction with systolic dysfunction

    DEFF Research Database (Denmark)

    Solomon, Scott D; Shin, Sung Hee; Shah, Amil

    2011-01-01

    Direct renin inhibitors provide an alternative approach to inhibiting the renin-angiotensin-aldosterone system (RAAS) at the most proximal, specific, and rate-limiting step. We tested the hypothesis that direct renin inhibition would attenuate left ventricular remodelling in patients following...

  2. Effect of the direct renin inhibitor aliskiren on left ventricular remodelling following myocardial infarction with systolic dysfunction

    DEFF Research Database (Denmark)

    Solomon, Scott D; Shin, Sung Hee; Shah, Amil

    2011-01-01

    Direct renin inhibitors provide an alternative approach to inhibiting the renin-angiotensin-aldosterone system (RAAS) at the most proximal, specific, and rate-limiting step. We tested the hypothesis that direct renin inhibition would attenuate left ventricular remodelling in patients following ac...

  3. SOUND ATTENUATION IN FERROELECTRIC SOLIDS

    OpenAIRE

    Naithani, U.; Semwal, B.

    1981-01-01

    An expression for the sound-attenuation constant in doped displacive ferroelectrics, in the presence of an external electric field, is obtained by using the double-time thermal- Green's -functions technique. The mass and force constant changes between the impurity and the host lattice atoms are taken into account in the Silverman Hamiltonian augmented with higher -order anharmonic and electric-moment terms. The defect-dependent, electric- field-dependent, and anharmonic contributions to the a...

  4. Flagella Overexpression Attenuates Salmonella Pathogenesis

    OpenAIRE

    Xinghong Yang; Theresa Thornburg; Zhiyong Suo; SangMu Jun; Amanda Robison; Jinquan Li; Timothy Lim; Ling Cao; Teri Hoyt; Recep Avci; Pascual, David W.

    2012-01-01

    Flagella are cell surface appendages involved in a number of bacterial behaviors, such as motility, biofilm formation, and chemotaxis. Despite these important functions, flagella can pose a liability to a bacterium when serving as potent immunogens resulting in the stimulation of the innate and adaptive immune systems. Previous work showing appendage overexpression, referred to as attenuating gene expression (AGE), was found to enfeeble wild-type Salmonella. Thus, this approach was adapted to...

  5. On Covers and Left-Corner Parses

    NARCIS (Netherlands)

    op den Akker, Hendrikus J.A.; Asveld, P.R.J.; Nijholt, Antinus

    1987-01-01

    A transformation is defined which is a modification of a classic transformation on context-free grammars. By means of this transformation, a proof is presented of the fact that any cycle-free context-free grammar can be left-to-left-corner covered by a non-left-recursive grammar. The proof method is

  6. Left Ventricular Pseudoaneurysm Found by CT Scan

    OpenAIRE

    Hirose, Hitoshi; Matsunaga, Iwao; Strong, Michael D

    2008-01-01

    A 62-year-old male with a previous coronary artery bypass grafting underwent CT scan for evaluation of left epigastric pain. Findings showed a large left ventricular pseudoaneurysm, which was subsequently confirmed by left ventriculogram. The pseudoaneurysm was successfully repaired surgically.

  7. Physical characteristics and attenuation of foam earplugs

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C.R.; Broughton, R.M.; Wilmoth, J.N.; Borton, T.E.; Mozo, B.T.

    1982-01-01

    The purpose of this investigation was twofold: (1) to determine the physical characteristics of five types of foam earplugs; and (2) to relate their physical characteristics to attenuation of noise. The results indicate that: (1) all commercial polymer foam earplugs have similar physical properties, (2) frequency is the single most important variable in determining attenuation of commercial foam earplugs, (3) all earplugs evaluated provided essentially the same attenuation at frequencies >500 Hz. One non-commercial earplug provided significantly more attenuation at 125 Hz than the other earplugs. This non-commercial experimental plug has significantly different physical and chemical properties. No other consistent effects of physical properties on attenuation were found.

  8. Method for Estimating Total Attenuation from a Spatial Map of Attenuation Slope for Quantitative Ultrasound Imaging

    OpenAIRE

    Pawlicki, Alexander D.; O'Brien, William D.

    2013-01-01

    Estimating total ultrasound attenuation from backscatter data is essential in the field of quantitative ultrasound (QUS) because of the need to compensate for attenuation when estimating the backscatter coefficient and QUS parameters. This work uses a reference phantom method of attenuation estimation to create a spatial map of attenuation slope (AS) from backscatter radio-frequency (RF) data of three phantoms and a rat mammary adenocarcinoma tumor (MAT). The attenuation maps show changes in ...

  9. Inhibition of NF-κB activity in the hypothalamic paraventricular nucleus attenuates hypertension and cardiac hypertrophy by modulating cytokines and attenuating oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xiao-Jing [Department of Physiology and Pathophysiology, Xi' an Jiaotong University School of Basic Medical Sciences, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University Health Science Center, Xi' an 710061 (China); Zhang, Dong-Mei [Department of Physiology, Dalian Medical University, Dalian 116044 (China); Jia, Lin-Lin; Qi, Jie; Song, Xin-Ai; Tan, Hong [Department of Physiology and Pathophysiology, Xi' an Jiaotong University School of Basic Medical Sciences, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University Health Science Center, Xi' an 710061 (China); Cui, Wei [Department of Endocrinology and Metabolism, First Affiliated Hospital of Xi' an Jiaotong University, Xi' an Jiaotong University Health Science Center, Xi' an 710061 (China); Chen, Wensheng [Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi' an 710032 (China); Zhu, Guo-Qing [Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029 (China); Qin, Da-Nian, E-mail: dnqin@stu.edu.cn [Department of Physiology, Shantou University Medical College, Shantou 515041 (China); Kang, Yu-Ming, E-mail: ykang@mail.xjtu.edu.cn [Department of Physiology and Pathophysiology, Xi' an Jiaotong University School of Basic Medical Sciences, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University Health Science Center, Xi' an 710061 (China)

    2015-05-01

    We hypothesized that chronic inhibition of NF-κB activity in the hypothalamic paraventricular nucleus (PVN) delays the progression of hypertension and attenuates cardiac hypertrophy by up-regulating anti-inflammatory cytokines, reducing pro-inflammatory cytokines (PICs), attenuating nuclear factor-κB (NF-κB) p65 and NAD(P)H oxidase in the PVN of young spontaneously hypertensive rats (SHR). Young normotensive Wistar–Kyoto (WKY) and SHR rats received bilateral PVN infusions with NF–κB inhibitor pyrrolidine dithiocarbamate (PDTC) or vehicle for 4 weeks. SHR rats had higher mean arterial pressure and cardiac hypertrophy as indicated by increased whole heart weight/body weight ratio, whole heart weight/tibia length ratio, left ventricular weight/tibia length ratio, cardiomyocyte diameters of the left cardiac ventricle, and mRNA expressions of cardiac atrial natriuretic peptide (ANP) and beta-myosin heavy chain (β-MHC). These SHR rats had higher PVN levels of proinflammatory cytokines (PICs), reactive oxygen species (ROS), the chemokine monocyte chemoattractant protein-1 (MCP-1), NAD(P)H oxidase activity, mRNA expression of NOX-2 and NOX-4, and lower PVN IL-10, and higher plasma levels of PICs and NE, and lower plasma IL-10. PVN infusion of NF-κB inhibitor PDTC attenuated all these changes. These findings suggest that NF-κB activation in the PVN increases sympathoexcitation and hypertensive response, which are associated with the increases of PICs and oxidative stress in the PVN; PVN inhibition of NF-κB activity attenuates PICs and oxidative stress in the PVN, thereby attenuates hypertension and cardiac hypertrophy. - Highlights: • Spontaneously hypertensive rats exhibit neurohormonal excitation in the PVN. • PVN inhibition of NF-κB attenuates hypertension-induced cardiac hypertrophy. • PVN inhibition of NF-κB attenuates hypertension-induced neurohormonal excitation. • PVN inhibition of NF-κB attenuates hypertension-induced imbalance of cytokines

  10. Giant and thrombosed left ventricular aneurysm.

    Science.gov (United States)

    de Agustin, Jose Alberto; de Diego, Jose Juan Gomez; Marcos-Alberca, Pedro; Rodrigo, Jose Luis; Almeria, Carlos; Mahia, Patricia; Luaces, Maria; Garcia-Fernandez, Miguel Angel; Macaya, Carlos; de Isla, Leopoldo Perez

    2015-07-26

    Left ventricular aneurysms are a frequent complication of acute extensive myocardial infarction and are most commonly located at the ventricular apex. A timely diagnosis is vital due to the serious complications that can occur, including heart failure, thromboembolism, or tachyarrhythmias. We report the case of a 78-year-old male with history of previous anterior myocardial infarction and currently under evaluation by chronic heart failure. Transthoracic echocardiogram revealed a huge thrombosed and calcified anteroapical left ventricular aneurysm. Coronary angiography demonstrated that the left anterior descending artery was chronically occluded, and revealed a big and spherical mass with calcified borders in the left hemithorax. Left ventriculogram confirmed that this spherical mass was a giant calcified left ventricular aneurysm, causing very severe left ventricular systolic dysfunction. The patient underwent cardioverter-defibrillator implantation for primary prevention.

  11. Left Ventricular Mechanics in Untrained and Trained Males with Tetraplegia.

    Science.gov (United States)

    Currie, Katharine D; West, Christopher R; Stöhr, Eric J; Krassioukov, Andrei V

    2017-02-01

    Reduced left ventricular (LV) function is common in tetraplegia, yet it is unknown whether intrinsic myocardial function is attenuated. This study examined the effect of SCI and exercise-training status on LV mechanics (intrinsic function) and LV systolic/diastolic function by comparing untrained (UT) and trained (TT) individuals with tetraplegia and able-bodied (AB) individuals. Individuals with tetraplegia had a traumatic, chronic, motor-complete cervical spinal cord injury. Nine UT males (40 ± 10 years), 8 TT males (30 ± 5 years), and nine AB males (37 ± 9 years) participated in the study. LV indices were assessed using two-dimensional transthoracic echocardiography, with speckle-tracking analysis for the determination of LV mechanics. For systolic function, stroke volumes were lower in both UT (59 ± 9 mL; p tetraplegia, attenuated LV systolic function is not attributed to intrinsic dysfunction, whereas exercise-training status appears to improve both global LV diastolic function and LV mechanics.

  12. Paradoxical Sleep Deprivation Causes Cardiac Dysfunction and the Impairment Is Attenuated by Resistance Training.

    Science.gov (United States)

    Giampá, Sara Quaglia de Campos; Mônico-Neto, Marcos; de Mello, Marco Tulio; Souza, Helton de Sá; Tufik, Sergio; Lee, Kil Sun; Koike, Marcia Kiyomi; Dos Santos, Alexandra Alberta; Antonio, Ednei Luiz; Serra, Andrey Jorge; Tucci, Paulo José Ferreira; Antunes, Hanna Karen Moreira

    2016-01-01

    Paradoxical sleep deprivation activates the sympathetic nervous system and the hypothalamus-pituitary-adrenal axis, subsequently interfering with the cardiovascular system. The beneficial effects of resistance training are related to hemodynamic, metabolic and hormonal homeostasis. We hypothesized that resistance training can prevent the cardiac remodeling and dysfunction caused by paradoxical sleep deprivation. Male Wistar rats were distributed into four groups: control (C), resistance training (RT), paradoxical sleep deprivation for 96 hours (PSD96) and both resistance training and sleep deprivation (RT/PSD96). Doppler echocardiograms, hemodynamics measurements, cardiac histomorphometry, hormonal profile and molecular analysis were evaluated. Compared to the C group, PSD96 group had a higher left ventricular systolic pressure, heart rate and left atrium index. In contrast, the left ventricle systolic area and the left ventricle cavity diameter were reduced in the PSD96 group. Hypertrophy and fibrosis were also observed. Along with these alterations, reduced levels of serum testosterone and insulin-like growth factor-1 (IGF-1), as well as increased corticosterone and angiotensin II, were observed in the PSD96 group. Prophylactic resistance training attenuated most of these changes, except angiotensin II, fibrosis, heart rate and concentric remodeling of left ventricle, confirmed by the increased of NFATc3 and GATA-4, proteins involved in the pathologic cardiac hypertrophy pathway. Resistance training effectively attenuates cardiac dysfunction and hormonal imbalance induced by paradoxical sleep deprivation.

  13. Healthy aging attenuates task-related specialization in the human medial temporal lobe

    DEFF Research Database (Denmark)

    Ramsøy, Thomas Z.; Liptrot, Matthew George; Skimminge, Arnold Jesper Møller

    2012-01-01

    of task related changes in the blood oxygen level-dependent (BOLD) signal was performed in native space after correction for gender effects and individual differences in cerebral blood flow. The hippocampus, amygdala, and parahippocampal, perirhinal, entorhinal, and temporopolar cortices of right and left...... prominent in the recognition stage. During recognition, the larger response to objects gradually decreased with age in all ROIs apart from left temporopolar and entorhinal cortex. An age-related attenuation was also present during encoding, but only in right parahippocampus and amygdala. Our results suggest...

  14. Method for estimating total attenuation from a spatial map of attenuation slope for quantitative ultrasound imaging.

    Science.gov (United States)

    Pawlicki, Alexander D; O'Brien, William D

    2013-04-01

    Estimating total ultrasound attenuation from backscatter data is essential in the field of quantitative ultrasound (QUS) because of the need to compensate for attenuation when estimating the backscatter coefficient and QUS parameters. This work uses a reference phantom method of attenuation estimation to create a spatial map of attenuation slope (AS) from backscatter radio-frequency (RF) data of three phantoms and a rat mammary adenocarcinoma tumor (MAT). The attenuation maps show changes in attenuation between different regions of the phantoms and the MAT tumor. Analyses of the attenuation maps of the phantoms suggest that the AS estimates are in good quantitative agreement with the known values for the phantoms. Furthermore, estimates of total attenuation from the attenuation maps are likewise in good quantitative agreement with known values.

  15. Left ventricular performance during triggered left ventricular pacing in patients with cardiac resynchronization therapy and left bundle branch block

    DEFF Research Database (Denmark)

    Witt, Christoffer Tobias; Kronborg, Mads Brix; Nohr, Ellen Aagaard

    2016-01-01

    complex >150 ms, QRS complex narrowing under CRT, and sinus rhythm were included ≥3 months after CRT implantation. Echocardiographic assessment of left ventricular ejection fraction (LVEF), global peak systolic longitudinal strain (GLS), and contraction pattern by 2D strain was performed during intrinsic......PURPOSE: To assess the acute effect of triggered left ventricular pacing (tLVp) on left ventricular performance and contraction pattern in patients with heart failure, left bundle branch block (LBBB), and cardiac resynchronization therapy (CRT). METHODS: Twenty-three patients with pre-implant QRS...

  16. Rg propagation: Scatter versus Attenuation

    Science.gov (United States)

    Cleveland, M.; Phillips, W. S.; MacCarthy, J.

    2016-12-01

    At near local distances, the Rg seismic phase is often the largest seismic arrival for shallow sources. While Rg is classically defined for the period range of 8-12 s, we use the term generically to refer to short-period observations of Rayleigh waves from shallow sources [e.g. Langston, 1987; Bonner and Russell, 2013]. There is significant interest in using Rg as a basis for seismic discrimination and magnitude (e.g. Bonner and Russell, 2013). However, the propagation of this phase is poorly understood. At Nevada National Security Site, while Rg is well observed near the source, it quickly disappears at greater distances. This observation raises the fundamental question of how much of the Rg energy is simply attenuating versus scattering into other seismic phases. Understanding this is critical to interpreting not only the observed Rg seismic energy, but also the possible enrichment of other seismic phases resulting from Rg scattering. In this study, we use waveform data from the Bighorn Arch Seismic Experiment (BASE) and Source Physics Experiment (SPE) to investigate Rg propagation, looking to identify how much energy from the phase attenuates with distance and how much scatters into other seismic phases.

  17. Chlorine signal attenuation in concrete.

    Science.gov (United States)

    Naqvi, A A; Maslehuddin, M; ur-Rehman, Khateeb; Al-Amoudi, O S B

    2015-11-01

    The intensity of prompt gamma-ray was measured at various depths from chlorine-contaminated silica fume (SF) concrete slab concrete specimens using portable neutron generator-based prompt gamma-ray setup. The intensity of 6.11MeV chloride gamma-rays was measured from the chloride contaminated slab at distance of 15.25, 20.25, 25.25, 30.25 and 35.25cm from neutron target in a SF cement concrete slab specimens. Due to attenuation of thermal neutron flux and emitted gamma-ray intensity in SF cement concrete at various depths, the measured intensity of chlorine gamma-rays decreases non-linearly with increasing depth in concrete. A good agreement was noted between the experimental results and the results of Monte Carlo simulation. This study has provided useful experimental data for evaluating the chloride contamination in the SF concrete utilizing gamma-ray attenuation method. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. SEISMIC ATTENUATION FOR RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Joel Walls; M.T. Taner; Naum Derzhi; Gary Mavko; Jack Dvorkin

    2003-12-01

    We have developed and tested technology for a new type of direct hydrocarbon detection. The method uses inelastic rock properties to greatly enhance the sensitivity of surface seismic methods to the presence of oil and gas saturation. These methods include use of energy absorption, dispersion, and attenuation (Q) along with traditional seismic attributes like velocity, impedance, and AVO. Our approach is to combine three elements: (1) a synthesis of the latest rock physics understanding of how rock inelasticity is related to rock type, pore fluid types, and pore microstructure, (2) synthetic seismic modeling that will help identify the relative contributions of scattering and intrinsic inelasticity to apparent Q attributes, and (3) robust algorithms that extract relative wave attenuation attributes from seismic data. This project provides: (1) Additional petrophysical insight from acquired data; (2) Increased understanding of rock and fluid properties; (3) New techniques to measure reservoir properties that are not currently available; and (4) Provide tools to more accurately describe the reservoir and predict oil location and volumes. These methodologies will improve the industry's ability to predict and quantify oil and gas saturation distribution, and to apply this information through geologic models to enhance reservoir simulation. We have applied for two separate patents relating to work that was completed as part of this project.

  19. Breast imaging using waveform attenuation tomography

    Science.gov (United States)

    Li, Cuiping; Sandhu, Gursharan Y.; Boone, Michael; Duric, Neb

    2017-03-01

    Ex vivo studies using our ultrasound waveform attenuation algorithm have shown promising results for detection and characterization of lesions of different types. Our preliminary in vivo study shows that the waveform attenuation image has much higher resolution and can better delineate breast lesions boundaries than the corresponding ray-based attenuation image. In this study, we preprocessed our time domain waveforms acquired with a ring array and explored the directional transducer beam pattern to better match calculated wave fields with respect to the acquired wave fields. We have applied waveform attenuation to in vivo data and compared the resulting waveform attenuation images with the ray-based counterparts to assess the resolution and accuracy of the waveform attenuation reconstruction.

  20. Multiplicativity of left centralizers forcing additivity

    Directory of Open Access Journals (Sweden)

    Mohammad Sayed Tammam El-Sayiad

    2014-01-01

    Full Text Available A multiplicative left centralizer for an associative ring R is a map satisfying T(xy = T\\(xy for all x,y in R. T is not assumed to be additive. In this paper we deal with the additivity of the multiplicative left centralizers in a ring which contains an idempotent element. Specially, we study additivity for multiplicative left centralizers in prime and semiprime rings which contain an idempotent element.

  1. Wave attenuation charcteristics of tethered float system

    Digital Repository Service at National Institute of Oceanography (India)

    Vethamony, P.

    parameters. The effect of drag on wave attenuation is studied for varying drag coefficient values. Theoretical results are compared with experimental values and it is found that theory overestimates wave attenuation which may probably be due to various... 15 and 16, respectively. These figures show that theory overestimates the wave attenuation and this may probably be due to various linearisations involved in the theoretical formulation. Experimental results are also not very accurate because...

  2. Lung attenuation measurements in healthy young adults.

    OpenAIRE

    Smit, H.J.M.; Golding, R.P.; Schramel, F.M.N.H.; Devillé, W.L.; Manoliu, R.A.; Postmus, P. E.

    2003-01-01

    Background: High-resolution computed tomography (HRCT) attenuation measurements may be more sensitive in finding early emphysematous changes in relatively young subjects than lung function measurements. Objectives: To define lung attenuation parameters in smokers and never-smokers. Methods: A prospective comparative study in a university hospital setting was designed with 20 healthy smoking and 20 nonsmoking volunteers. Attenuation measurements on spirometrically controlled HRCT at three leve...

  3. Cilia in vertebrate left-right patterning.

    Science.gov (United States)

    Dasgupta, Agnik; Amack, Jeffrey D

    2016-12-19

    Understanding how left-right (LR) asymmetry is generated in vertebrate embryos is an important problem in developmental biology. In humans, a failure to align the left and right sides of cardiovascular and/or gastrointestinal systems often results in birth defects. Evidence from patients and animal models has implicated cilia in the process of left-right patterning. Here, we review the proposed functions for cilia in establishing LR asymmetry, which include creating transient leftward fluid flows in an embryonic 'left-right organizer'. These flows direct asymmetric activation of a conserved Nodal (TGFβ) signalling pathway that guides asymmetric morphogenesis of developing organs. We discuss the leading hypotheses for how cilia-generated asymmetric fluid flows are translated into asymmetric molecular signals. We also discuss emerging mechanisms that control the subcellular positioning of cilia and the cellular architecture of the left-right organizer, both of which are critical for effective cilia function during left-right patterning. Finally, using mosaic cell-labelling and time-lapse imaging in the zebrafish embryo, we provide new evidence that precursor cells maintain their relative positions as they give rise to the ciliated left-right organizer. This suggests the possibility that these cells acquire left-right positional information prior to the appearance of cilia.This article is part of the themed issue 'Provocative questions in left-right asymmetry'. © 2016 The Author(s).

  4. Left Ventricular Thrombosis in Ulcerative Colitis

    Directory of Open Access Journals (Sweden)

    Tarek Saleh

    2010-07-01

    Full Text Available Left ventricular thrombi usually occur in the setting of an acute myocardial infarction, left ventricular aneurysm, or dilated cardiomyopathy. In the absence of ventricular wall motion abnormalities, they are rare. This report describes a patient with ulcerative colitis in whom two-dimensional echocardiography revealed a left intraventricular mass. Thrombosis in ulcerative colitis is a serious condition and can occur in a very young population. This case also shows that left ventricular thrombi can occur in the active setting of ulcerative colitis.

  5. Left-sided omental torsion: CT appearance

    Energy Technology Data Exchange (ETDEWEB)

    Aoun, N.; Haddad-Zebouni, S.; Slaba, S.; Ghossain, M. [Hotel-Dieu de France Hospital, Beirut (Lebanon). Dept. of Radiology; Noun, R. [Hotel-Dieu de France Hospital, Beirut (Lebanon). Dept. of General Surgery

    2001-01-01

    A 34-year-old male presented with exquisite left flank pain. Computed tomography showed a hyperdense vascular structure surrounded by whirling linear streaks situated in the greater omentum under the splenic flexure of the colon. Omental stranding extended caudally into the pelvis where part of the inflamed omentum entered a left inguinal hernia sac. Surgery revealed left-sided torsion of the greater omentum. Left-sided omental torsion is infrequent and pre-operative diagnosis is rarely established. The CT findings of an omental fatty mass with a whirling pattern is characteristic of omental torsion. Preoperative diagnosis is important because conservative management has been suggested. (orig.)

  6. Anarchy, socialism and a Darwinian left.

    Science.gov (United States)

    Clarke, Ellen

    2006-03-01

    In A Darwinian left Peter Singer aims to reconcile Darwinian theory with left wing politics, using evolutionary game theory and in particular a model proposed by Robert Axelrod, which shows that cooperation can be an evolutionarily successful strategy. In this paper I will show that whilst Axelrod's model can give support to a kind of left wing politics, it is not the kind that Singer himself envisages. In fact, it is shown that there are insurmountable problems for the idea of increasing Axelrodian cooperation within a welfare state. My surprising conclusion will be that a Darwinian left worthy of the name would be anarchistic.

  7. Noiseless attenuation using an optical parametric amplifier

    Science.gov (United States)

    Brewster, R. A.; Nodurft, I. C.; Pittman, T. B.; Franson, J. D.

    2017-10-01

    The process of heralded noiseless amplification, and the inverse process of heralded noiseless attenuation, have potential applications in the context of quantum communications. Although several different physical implementations of heralded noiseless amplifiers have now been demonstrated, the research on heralded noiseless attenuators has been largely confined to a beam-splitter based approach. Here we show that an optical parametric amplifier (OPA), combined with appropriate heralding, can also serve as a heralded noiseless attenuator. The counterintuitive use of an optical amplifier as an attenuator is only possible due to the probabilistic nature of the device.

  8. Left atrial systolic force in hypertensive patients with left ventricular hypertrophy: the LIFE study

    DEFF Research Database (Denmark)

    Chinali, M.; Simone, G. de; Wachtell, K.

    2008-01-01

    with larger left ventricular diameter and higher left ventricular mass index (both P hypertrophy was greater (84 vs. 64%; P cardiac output......In hypertensive patients without prevalent cardiovascular disease, enhanced left atrial systolic force is associated with left ventricular hypertrophy and increased preload. It also predicts cardiovascular events in a population with high prevalence of obesity. Relations between left atrial......, transmitral peak E velocities and peak A velocities; and lower E/A ratio (all P hypertrophy, but normal left ventricular chamber systolic function with increased...

  9. On establishing coreference in Left Dislocation constructions ...

    African Journals Online (AJOL)

    The phenomenon of left dislocation (LD) has received relatively little attention in the generative literature. In Government & Binding theory and early versions of Minimalist Syntax, the left-dislocated expression is conventionally taken to be base-generated in its sentence-initial surface position and the resumptive pronoun in ...

  10. Malignant phyllodes tumor of the left atrium

    Directory of Open Access Journals (Sweden)

    Anupam Bhambhani

    2014-03-01

    Full Text Available Metastatic tumors to the heart usually involve right sided chambers. We report a rare case of malignant phyllodes tumor of breast with metastatic involvement of left atrium occurring through direct invasion from mediastinal micro-metastasis and presenting as a left atrial mass causing arrhythmia.

  11. Leptogenesis with left-right domain walls

    Indian Academy of Sciences (India)

    the scale of left-right symmetry breaking. Keywords. Leptogenesis; baryogenesis; domain walls; left-right symmetry. PACS Nos 12.10.Dm; 98.80.Cq; 98.80.Ft. Explaining the observed baryon asymmetry of the Universe within the framework of gauge theories and the standard Big Bang cosmology remains an open problem.

  12. On establishing coreference in Left Dislocation constructions

    African Journals Online (AJOL)

    user

    The phenomenon of left dislocation (LD) has received relatively little attention in the generative literature. In Government & Binding theory and early versions of Minimalist Syntax, the left- dislocated expression is conventionally taken to be base-generated in its sentence-initial surface position and the resumptive pronoun in ...

  13. Left Brain, Right Brain: Who's on First?

    Science.gov (United States)

    Hines, Terence

    1985-01-01

    The author states that none of the left-brain/right brain "mythology" is supported by the actual research on the differences between the left and right human cerebral hemispheres. In fact, he states, the research literature flatly contradicts most of the mythology. (CT)

  14. The left and right periphery in Dutch

    NARCIS (Netherlands)

    de Vries, M.

    2009-01-01

    This article discusses the information-structural status and the syntax of left and right dislocation constructions in Dutch. Four orthogonal information-structural features are proposed, and their distribution is systematically investigated. Furthermore, it is argued that hanging topic left

  15. Submitral left ventricular aneurysm associated with thrombus ...

    African Journals Online (AJOL)

    Methods: In April 2017, a 25-year-old patient havingsubmitral left ventricular aneurysm with New York Heart Association (NYHA) class IV heart failure and mild left ventricular systolic dysfunctionreceived medical treatment at our institution. She had severe mitral regurgitation and aneurysmal thrombus. The diagnosis was ...

  16. On the covering of left recursive grammars

    NARCIS (Netherlands)

    Nijholt, Antinus; Aho, A.V.

    In this paper we show that some prevailing ideas on the elimination of left recursion in a context-free grammar are not valid. An algorithm and a proof are given to show that every proper context-free grammar is covered by a non-left-recursive grammar.

  17. Pure Left Neglect for Arabic Numerals

    Science.gov (United States)

    Priftis, Konstantinos; Albanese, Silvia; Meneghello, Francesca; Pitteri, Marco

    2013-01-01

    Arabic numerals are diffused and language-free representations of number magnitude. To be effectively processed, the digits composing Arabic numerals must be spatially arranged along a left-to-right axis. We studied one patient (AK) to show that left neglect, after right hemisphere damage, can selectively impair the computation of the spatial…

  18. Malignant phyllodes tumor of the left atrium

    OpenAIRE

    Bhambhani, Anupam; Ayyagari, Sudha; Mohapatra, Tushar; Rehman, Syed Abdul; Shah, Milap; Rao, Sudhakar; Rangashamanna, Vital; Rajasekhar, V.; Chittimilla, Santosh

    2014-01-01

    Metastatic tumors to the heart usually involve right sided chambers. We report a rare case of malignant phyllodes tumor of breast with metastatic involvement of left atrium occurring through direct invasion from mediastinal micro-metastasis and presenting as a left atrial mass causing arrhythmia.

  19. Horseshoe lung with left lung hypoplasia.

    OpenAIRE

    Ersöz, A; Soncul, H; Gökgöz, L; Kalaycioğlu, S; Tunaoğlu, S; Kaptanoğlu, M; Yener, A

    1992-01-01

    Horseshoe lung is an uncommon congenital malformation in which the bases of the right and the left lungs are fused to each other by a narrow isthmus posterior to the cardiac apex. So far 22 cases have been described: most of these were associated with right lung hypoplasia and the scimitar syndrome. A horseshoe lung anomaly with left lung hypoplasia is described.

  20. Left ventricular hypertrophy, geometric patterns and clinical ...

    African Journals Online (AJOL)

    Background: Left ventricular hypertrophy can be due to various reasons including hypertension. It constitutes an increased cardiovascular risk. Various left ventricular geometric patterns occur in hypertension and may affect the cardiovascular risk profile of hypertensive subjects. Methods: One hundred and eighty eight ...

  1. Left Paraduodenal Hernia: An Autopsy Case

    DEFF Research Database (Denmark)

    Omland, Silje Haukali; Hougen, Hans Petter

    2011-01-01

    We present a case of a left paraduodenal hernia diagnosed at autopsy. A left paraduodenal hernia is an internal hernia of congenital origin due to the abnormal rotation of the midgut during embryonic development. Internal hernias are a rare cause of intestinal obstruction, with the paraduodenal...

  2. A new clinical sign probably associated to left hemiplegia with left hemineglect syndrome: the crossed legs.

    Science.gov (United States)

    Bazan, Rodrigo; Fernandes, Thiago; Braga, Gabriel; Luvizutto, Gustavo; Resende, Luiz

    2014-06-01

    To describe a new clinical sign associated with left unilateral neglect syndrome (UNS) in patients with ischemic stroke. Head computed tomography (CT) and National Institute of Health Stroke Scale were obtained in 150 patients with ischemic stroke. Those with right cerebral vascular lesions, left hemiplegia and right leg persistently crossed over the left were submitted to specific tests for UNS. The tests were also applied to 30 patients with right cerebral vascular lesions, left hemiplegia but without crossed legs. From 9 patients with persistent tendency to cross the right leg over the left, UNS was detected in 8. One patient died before the clinical tests were applied. Of the 30 patients without the crossed legs, 20 had normal clinical tests for UNS and 10 had minimal alterations, not sufficient for the diagnosis of UNS. The right leg crossed over the left may represent a new neurological semiotic sign associated with left hemiplegia and left UNS.

  3. VARIATION IN THE OPENINGS (OSTIA OF LEFT PULMONARY VEINS INTO THE LEFT ATRIUM: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Sesi

    2015-03-01

    Full Text Available During early embryonic development, absorption of pulmonary venous network by the left primitive atrial chamber results in opening of four pulmonary veins which drain independently into its chamber. The extent of absorption and hence, the number of pulmon ary veins which open into the left atrium, may vary. Here we report a variation in the opening of the Left upper (superior pulmonary vein into the Left atrium. A total of six openings observed

  4. Left Atrial Decompression by Percutaneous Left Atrial Venting Cannula Insertion during Venoarterial Extracorporeal Membrane Oxygenation Support

    Directory of Open Access Journals (Sweden)

    Ha Eun Kim

    2016-06-01

    Full Text Available Patients with venoarterial extracorporeal membrane oxygenation (ECMO frequently suffer from pulmonary edema due to left ventricular dysfunction that accompanies left heart dilatation, which is caused by left atrial hypertension. The problem can be resolved by left atrium (LA decompression. We performed a successful percutaneous LA decompression with an atrial septostomy and placement of an LA venting cannula in a 38-month-old child treated with venoarterial ECMO for acute myocarditis.

  5. Multiple attenuation using eigenvalue decomposition | Aigbedion ...

    African Journals Online (AJOL)

    Multiple reflections constitute one of the most troublesome forms of coherent noise in seismic exploration, especially in marine surveys. There are many approaches to attenuating or suppressing multiples, but none can remove all multiple reflections under all conditions. We have eveloped two new methods to attenuate ...

  6. ATTENUATION AND FLANKING TRANSMISSION IN LIGHTWEIGHT STRUCTURES

    DEFF Research Database (Denmark)

    Brunskog, Jonas; Lhomond, Alice; Ohlrich, Mogens

    2007-01-01

    In this paper the attenuation and flanking transmissions of impact noise in lightweight building structures is studied using a modal approach. The structural field is mainly analysed, putting the main attention to the parts being important in the modelling. The amount of attenuation produced...

  7. Precision Model for Microwave Rotary Vane Attenuator

    DEFF Research Database (Denmark)

    Guldbrandsen, Tom

    1979-01-01

    A model for a rotary vane attenuator is developed to describe the attenuator reflection and transmission coefficients in detail. All the parameters of the model can be measured in situ, i.e., without diassembling any part. The tranmission errors caused by internal reflections are calculated from...

  8. Attenuation coefficients for water quality trading.

    Science.gov (United States)

    Keller, Arturo A; Chen, Xiaoli; Fox, Jessica; Fulda, Matt; Dorsey, Rebecca; Seapy, Briana; Glenday, Julia; Bray, Erin

    2014-06-17

    Water quality trading has been proposed as a cost-effective approach for reducing nutrient loads through credit generation from agricultural or point source reductions sold to buyers facing costly options. We present a systematic approach to determine attenuation coefficients and their uncertainty. Using a process-based model, we determine attenuation with safety margins at many watersheds for total nitrogen (TN) and total phosphorus (TP) loads as they transport from point of load reduction to the credit buyer. TN and TP in-stream attenuation generally increases with decreasing mean river flow; smaller rivers in the modeled region of the Ohio River Basin had TN attenuation factors per km, including safety margins, of 0.19-1.6%, medium rivers of 0.14-1.2%, large rivers of 0.13-1.1%, and very large rivers of 0.04-0.42%. Attenuation in ditches transporting nutrients from farms to receiving rivers is 0.4%/km for TN, while for TP attenuation in ditches can be up to 2%/km. A 95 percentile safety margin of 30-40% for TN and 6-10% for TP, applied to the attenuation per km factors, was determined from the in-stream sensitivity of load reductions to watershed model parameters. For perspective, over 50 km a 1% per km factor would result in 50% attenuation = 2:1 trading ratio.

  9. TMS over the Left Angular Gyrus Impairs the Ability to Discriminate Left from Right

    Science.gov (United States)

    Hirnstein, Marco; Bayer, Ulrike; Ellison, Amanda; Hausmann, Markus

    2011-01-01

    The underlying cognitive and neural mechanisms of the ability to discriminate left from right are hardly explored. Clinical studies from patients with impairments of left-right discrimination (LRD) and neuroimaging data suggest that the left angular gyrus is particularly involved in LRD. Moreover, it is argued that the often reported sex…

  10. Loads Induced on a Flat-Plate Wing by an Air Jet Exhausting Perpendicularly through the Wing and Normal to a Free-Stream Flow of Mach Number 2.0

    Science.gov (United States)

    Janos, Joseph J.

    1961-01-01

    Measurements were made of loads induced on a flat-plate wing by an air jet exhausting perpendicularly through the wing and normal to the free-stream flow.The investigation was conducted at a free-stream Mach number of 2.0 and a Reynolds number per foot of 14.4 x 10(exp 6). An axially symmetric sonic nozzle and two supersonic nozzles were employed for the jets. The supersonic nozzles consisted of an axially symmetric nozzle with exit Mach number of 3.44 and a two-dimensional nozzle with exit Mach number of 1.76. The ratio of nozzle total pressure to free-stream static pressure was varied from 20 to 110. Negative loads were induced on the flat-plate wing by all the jets. As the nozzle pressure ratio was increased the magnitude of interference loads due to jet thrust decreased. The chordwise center-of-pressure location generally moved toward the nozzle center line as the pressure ratio was increased.

  11. Ultrasound fields in an attenuating medium

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt; Gandhi,, D; O'Brien,, W.D., Jr.

    1993-01-01

    of the rectangles and sums all contributions to arrive at the spatial impulse response for the aperture and field point. This approach makes it possible to model all transducer apertures, and the program can readily calculate the emitted, pulse-echo and continuous wave field. Attenuation is included by splitting...... it into a frequency dependent part and frequency independent part. The latter results in an attenuation factor that is multiplied onto the responses from the individual elements, and the frequency dependent part is handled by attenuating the basic one-dimensional pulse. The influence on ultrasound fields from......Ultrasound fields propagating in tissue will undergo changes in shape not only due to diffraction, but also due to the frequency dependent attenuation. Linear fields can be fairly well predicted for a non-attenuating medium like water by using the Tupholme-Stepanishen method for calculating...

  12. [Social aspects of left-handedness].

    Science.gov (United States)

    Milenković, Sanja; Belojević, Goran; Kocijancić, Radojka

    2010-01-01

    Throughout human history left-handedness has been considered as sinful. It has been associated with the devil, weakness, female gender, unhealthiness, evil, something that has to be turned to a "good"--right side by force. Left-handedness is being more and more acceptable at rational level, but in everyday life it is still considered to be unusual if someone writes with the left hand. Lessening of the number of lefthanders is associated with ageing. There are about 13% lefthanders among people in twenties and less than 1% lefthanders among those in eighties. This finding may be explaned with more pronounced socio-cultural pressure on left-handed people in the past, compared to nowadays. On the other hand, this may also support the hypothesis about a reduced life span of lefthanded people. With cross-exercising of left-handedness, certain typical characteristics and behavioural patterns appear in these people. This was a sort of provoked behaviour and an attack on the integrity of an emotional attitude toward oneself. Stuttering may also appear as a consequence of unsuccessful cross-exercising of left-handedness. The hypothesis about left-handedness as an advantage is supported with the reports about relatively more lefthanders in some specific groups such as: mathematicians, sculptors, architects, painters, musicians, actors, tennis players, as well as famous army commanders and rulers.

  13. Social aspects of left-handedness

    Directory of Open Access Journals (Sweden)

    Belojević Goran

    2010-01-01

    Full Text Available Throughout human history left-handedness has been considered as sinful. It has been associated with the devil, weakness, female gender, unhealthiness, evil, something that has to be turned to a “good” - right side by force. Left-handedness is being more and more acceptable at rational level, but in everyday life it is still considered to be unusual if someone writes with the left hand. Lessening of the number of lefthanders is associated with ageing. There are about 13% lefthanders among people in twenties and less than 1% lefthanders among those in eighties. This finding may be explaned with more pronounced socio-cultural pressure on left-handed people in the past, compared to nowadays. On the other hand, this may also support the hypothesis about a reduced life span of lefthanded people. With cross-exercising of left-handedness, certain typical characteristics and behavioral patterns appear in these people. This was a sort of provoked behavior and an attack on the integrity of an emotional attitude toward oneself. Stuttering may also appear as a consequence of unsuccessful cross-exercising of left-handedness. The hypothesis about left-handedness as an advantage is supported with the reports about relatively more lefthanders in some specific groups such as: mathematicians, sculptors, architects, painters, musicians, actors, tennis players, as well as famous army commanders and rulers.

  14. Comparison of methods for determining absolute left ventricular volumes from radionuclide ventriculography

    Energy Technology Data Exchange (ETDEWEB)

    Warren, S.E.; McKay, R.G.; Aroesty, J.M.; Heller, G.V.; Kolodny, G.M.; Royal, H.D.

    1987-01-01

    Several radionuclide techniques have been used in routine clinical nuclear medicine practice as a means of quantitating left ventricular chamber volumes in man. Despite wide use and availability of the different techniques, however, there has not been a thorough comparison of radionuclide and contrast angiographic measurements performed in the same patients in close temporal proximity. Accordingly, in order to validate traditional methods of ventricular volume measurement, we have performed contrast ventriculography followed immediately (upon return of baseline hemodynamics) by gated radionuclide ventriculography in 34 patients undergoing diagnostic cardiac catheterization. Absolute left ventricular end-diastolic volumes were determined from single-plane, right anterior oblique, end-diastolic contrast silhouettes using a standard area-length method. Radionuclide ventriculographic volumes were determined by three methods: planimetry (32 patients), counts-based (19 patients), and thermodilution stroke volume/radionuclide ejection fraction (32 patients). With planimetry, an area-length method was used in which the modified left anterior oblique left ventricular image was assumed to be a prolate ellipsoid whose volume can be determined by measuring surface area and the ventricular long axis. With the counts-based technique, a blood sample was drawn at the midpoint of the radionuclide ventriculogram acquisition and counted with a gamma camera with appropriate attenuation factor correction. With the thermodilution stroke volume/radionuclide ejection fraction technique, the left ventricular stroke volume was determined by dividing thermodilution cardiac output by the heart rate.

  15. An Unusual Left Ventricular Apical Mass

    Science.gov (United States)

    Cavallero, Erika; Curzi, Mirko; Cioccarelli, Sara Anna; Papalia, Giulio; Ornaghi, Diego; Bragato, Renato Maria

    2014-01-01

    Left ventricular apical masses constitute a rare finding. Imaging properties together with the clinical history of the patient usually allow an etiologic definition. We report a challenging case of an ambiguous left ventricular apical mass of uncertain nature till histological examination. Points of interest were singular clinical history and echocardiographic findings, although not conclusive in hypothesis generating. Furthermore to the best of our knowledge, this is one of the rare attempt to excise a deep left ventricular mass with a mini-invasive surgical approach. PMID:28465915

  16. Axis deviation without left bundle branch block.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo; Mancuso, Antonia

    2010-04-15

    It has been rarely reported changing axis deviation in the presence of left bundle branch block also during atrial fibrillation and with acute myocardial infarction too. It has also been rarely reported changing axis deviation with changing bundle branch block with onset of atrial fibrillation during acute myocardial infarction. We present a case of axis deviation without left bundle branch block and without atrial fibrillation and acute myocardial infarction in a 65-year-old Italian man. To our knowledge, this is the first report of axis deviation without left bundle branch block and without atrial fibrillation and acute myocardial infarction. Copyright 2008 Elsevier Ireland Ltd. All rights reserved.

  17. Transport and attenuation of radiations

    CERN Document Server

    Nimal, J C

    2003-01-01

    This article treats of the calculation methods used for the dimensioning of the protections against radiations. The method consists in determining for a given point the flux of particles coming from a source at a given time. A strong attenuation (of about some few mu Sv.h sup - sup 1) is in general expected between the source and the areas accessible to the personnel or the public. The calculation has to take into account a huge number of radiation-matter interactions and to solve the integral-differential transport equation which links the particles flux to the source. Several methods exist from the simplified physical model with numerical developments to the more or less precise resolution of the transport equation. These methods allows also the calculation of the uncertainties of equivalent dose rates, heat sources, structure damages using the data covariances (efficient cross-sections, modeling, etc..): 1 - transport equation; 2 - Monte-Carlo method; 3 - semi-numerical methods S sub N; 4 - methods based o...

  18. Transcortical sensory aphasia following left frontal infarction.

    Science.gov (United States)

    Otsuki, M; Soma, Y; Koyama, A; Yoshimura, N; Furukawa, H; Tsuji, S

    1998-02-01

    Two right-handed patients who exhibited language disability after left frontal infarction are described. The patients spoke fluently and exhibited excellent repetition ability from the onset of infarction without exhibiting any oral apraxia, but had deficits in auditory comprehension, naming, reading and writing. In both patients, brain magnetic resonance imaging (MRI) revealed infarction in the left inferior frontal gyrus, the middle frontal gyrus and the anterior part of the lower precentral gyrus. Single photon emission computed tomography (SPECT) revealed decreased blood flow in the same regions as those shown to be infarcted by MRI. The MRI and SPECT findings and the symptoms of these patients suggest that left frontal lesions that encompass Broca's area produce fluent aphasia if the posterior part of the left precentral gyrus or motor cortex remains intact and that lesions anterior to Broca's area and the middle frontal gyrus produce a deficit in auditory comprehension of single words as well as sentences.

  19. Are You Communicating Left or Right?

    Science.gov (United States)

    Swanson, Jean C.

    1992-01-01

    Describes an assignment that begins with a short questionnaire to determine students' dominant mode of thinking. Discusses differences between left- and right-mode thinking patterns and how communication is affected by domination of either mode. (SR)

  20. Beware the left-sided gallbladder

    African Journals Online (AJOL)

    %, and is defined as a gallbladder located to the left of the ligamentum teres and the falciform ligament.1 LSGB was first described by Hochstetter in 1886, and its identification is important because of the numerous and potentially hazardous.

  1. Electrocardiographic features suggestive of a left. ventricular ...

    African Journals Online (AJOL)

    Abstract. Electrocardiographic features suggestive of a transmural anterior myocardial infarction with resultant left ventricular aneurysm formation were found in a 22-year-old man who had sustained a ballistic missile injury to his chest.

  2. Applications of magnetic resonance imaging in the assessment of left ventricular dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Beacock, David John

    2002-07-01

    This thesis has described the use of Magnetic Resonance Imaging (MRI) in the investigation of left ventricular dimensions and systolic function. This has been performed in conditions of left ventricular dysfunction, in congestive cardiac failure and following anterior myocardial infarction. The reproducibility of measurements of left ventricular dimensions using MRI has been presented. Such measurements were shown to be reproducible between different MRI studies of normal volunteers and patients with congestive heart failure. Furthermore, measurements from different MRI studies obtained from two commercially different systems were reproducible for the same subject groups. Ventricular dimensions and systolic function was evaluated in adult normal volunteers of different ages. Although left ventricular volumes and mass remained unchanged, detailed studies of the systolic images revealed significant differences between the two age groups. Differences in left ventricular cavity volumes and mass between patients with congestive heart failure and age-matched normal volunteers were also investigated. Left ventricular volumes and myocardial mass were assessed in a group of patients following anterior myocardial infarction. End-systolic volume was significantly increased compared to age-matched volunteers, but no changes in end-diastolic volume or myocardial mass was observed. Serial re-evaluation of these patients revealed no other changes over the subsequent six months. All these patients were treated with optimal medical therapy (thrombolysis, aspirin, beta-blockade and angiotensin converting enzyme inhibition). Thus, the use of this therapy may attenuate the process of left ventricular remodelling. Regional wall thickness was measured in the post-infarct patients. Wall thickening was significantly reduced both in the infarcted regions and in myocardium remote to the infarction. In contrast to previous echocardiographic studies, no 'hypercontractility' was

  3. Congenital left atrial appendage aneurysm: Atypical presentation

    Directory of Open Access Journals (Sweden)

    Mehdi Bamous

    2017-01-01

    Full Text Available Congenital left atrial appendage aneurysm is a rare condition caused by dysplasia of the atrial muscles. We report a case of a 14-year-old boy, with a 5-month history of cough and in sinus rhythm. Transthoracic echocardiography and computerized tomographic angiography confirmed the aneurysm of the left atrial appendage which was resected through median sternotomy on cardiopulmonary bypass. This case is presented not only for its rarity but also for its atypical clinical presentation.

  4. The left side of motor resonance.

    Science.gov (United States)

    Sartori, Luisa; Begliomini, Chiara; Panozzo, Giulia; Garolla, Alice; Castiello, Umberto

    2014-01-01

    Motor resonance is defined as the internal activation of an observer's motor system, specifically attuned to the perceived movement. In social contexts, however, different patterns of observed and executed muscular activation are frequently required. This is the case, for instance, of seeing a key offered with a precision grip and received by opening the hand. Novel evidence suggests that compatibility effects in motor resonance can be altered by social response preparation. What is not known is how handedness modulates this effect. The present study aimed at determining how a left- and a right-handed actor grasping an object and then asking for a complementary response influences corticospinal activation in left- and right-handers instructed to observe the scene. Transcranial magnetic stimulation (TMS)-induced motor evoked potentials (MEPs) were thus recorded from the dominant hands of left- and right-handers. Interestingly, requests posed by the right-handed actor induced a motor activation in the participants' respective dominant hands, suggesting that left-handers tend to mirror right-handers with their most efficient hand. Whereas requests posed by the left-handed actor activated the anatomically corresponding muscles (i.e., left hand) in all the participants, right-handers included. Motor resonance effects classically reported in the literature were confirmed when observing simple grasping actions performed by the right-handed actor. These findings indicate that handedness influences both congruent motor resonance and complementary motor preparation to observed actions.

  5. Attenuation caused by infrequently updated covariates in survival analysis

    DEFF Research Database (Denmark)

    Andersen, Per Kragh; Liestøl, Knut

    2003-01-01

    Attenuation; Cox regression model; Measurement errors; Survival analysis; Time-dependent covariates......Attenuation; Cox regression model; Measurement errors; Survival analysis; Time-dependent covariates...

  6. Verapamil and angiotensin-converting enzyme inhibitors in patients with coronary artery disease and reduced left ventricular ejection fraction

    DEFF Research Database (Denmark)

    Hansen, J F; Tingsted, L; Rasmussen, Verner

    1996-01-01

    Verapamil is effective as antianginal medication but contraindicated in patients with congestive heart failure. Angiotensin-converting enzyme (ACE) inhibitors improve survival in patients with congestive heart failure but have limited effect on patients with angina pectoris. No studies have been.......4 to 2.5 +/- 0.6 (p attacks were both significantly reduced after 3 months of treatment. These findings support the hypothesis that the combination of verapamil and trandolapril is useful in patients with attenuated left ventricular function...

  7. Seismic attenuation system for a nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Liszkai, Tamas; Cadell, Seth

    2018-01-30

    A system for attenuating seismic forces includes a reactor pressure vessel containing nuclear fuel and a containment vessel that houses the reactor pressure vessel. Both the reactor pressure vessel and the containment vessel include a bottom head. Additionally, the system includes a base support to contact a support surface on which the containment vessel is positioned in a substantially vertical orientation. An attenuation device is located between the bottom head of the reactor pressure vessel and the bottom head of the containment vessel. Seismic forces that travel from the base support to the reactor pressure vessel via the containment vessel are attenuated by the attenuation device in a direction that is substantially lateral to the vertical orientation of the containment vessel.

  8. Immunisation status and determinants of left-behind children aged 12-72 months in central China.

    Science.gov (United States)

    Ni, Z L; Tan, X D; Shao, H Y; Wang, Y

    2017-07-01

    Many parents move from rural China to urban areas in search of job opportunities, and leave their children behind to be raised by relatives. We aimed to assess the immunisation coverage, including the 1:3:3:3:1 vaccine series (one dose of Bacilli Chalmette-Guérin vaccine; three doses of live attenuated oral poliomyelitis vaccine; three doses of diphtheria, tetanus and pertussis combined; three doses of hepatitis B vaccine; and one dose of measles-containing vaccine), in children aged 12-72 months and identify the determinants of immunisation uptake among left-behind children in Hubei Province, Central China, in 2014. In this cross-sectional study using the World Health Organization's cluster sampling technique, we surveyed 1368 children from 44 villages in 11 districts of Hubei Province. The socio-demographic and vaccination status data were collected by interviewing primary caregivers using a semi-structured questionnaire and reviewing the immunisation cards of the children. Univariate and multivariate analyses were used to identify the determinants of complete vaccination and age-appropriate vaccination. For each dose of the five vaccines, the vaccination coverage in the left-behind and non-left-behind children was >90%; however, the age-appropriate vaccination coverage for each vaccine was lower in left-behind than in non-left-behind children. For the five vaccines, the fully vaccinated rate of left-behind children were lower than those of non-left-behind children (89·1%, 92·7%; P = 0·013) and age-appropriate immunisation rate of left-behind children were lower than those of non-left-behind children (65·7%, 79·9%; P immunisation coverage rate among left-behind children in rural areas should be further improved by delivering and sustaining primary care services.

  9. Electron Effective-Attenuation-Length Database

    Science.gov (United States)

    SRD 82 NIST Electron Effective-Attenuation-Length Database (PC database, no charge)   This database provides values of electron effective attenuation lengths (EALs) in solid elements and compounds at selected electron energies between 50 eV and 2,000 eV. The database was designed mainly to provide EALs (to account for effects of elastic-eletron scattering) for applications in surface analysis by Auger-electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS).

  10. Post-Retrieval Extinction Attenuates Cocaine Memories

    OpenAIRE

    Sartor, Gregory C.; Aston-Jones, Gary

    2013-01-01

    Recent studies have shown that post-retrieval extinction training attenuates fear and reward-related memories in both humans and rodents. This noninvasive, behavioral approach has the potential to be used in clinical settings to treat maladaptive memories that underlie several psychiatric disorders, including drug addiction. However, few studies to date have used a post-retrieval extinction approach to attenuate addiction-related memories. In the current study, we attempted to disrupt cocaine...

  11. Attenuation of Shock Waves using Perforated Plates

    Science.gov (United States)

    Pavan Kumar, CH V. L. C. S.; Hitesh Reddy, C.; Rahul Sai, L.; Dharani Kumar, K. S. S.; Nagaraja, S. R.

    2017-08-01

    The shock/blast waves generated due to explosions cause wide spread damage to the objects in its path. Different techniques have been used to attenuate shock wave over pressure, to reduce the catastrophic effects. Perforated plates can be used effectively to attenuate the shock wave pressure. In this paper shock wave interaction with perforated plates is simulated using COMSOL multiphysics software. The pressure drop varied from 43.75% to 26% for porosity varying from 10% to 40.

  12. Attenuation coefficients for water quality trading

    OpenAIRE

    Keller, AA; Chen, X.; Fox, J; Fulda, M; Dorsey, R.; Seapy, B; Glenday, J; E Bray

    2014-01-01

    Water quality trading has been proposed as a cost-effective approach for reducing nutrient loads through credit generation from agricultural or point source reductions sold to buyers facing costly options. We present a systematic approach to determine attenuation coefficients and their uncertainty. Using a process-based model, we determine attenuation with safety margins at many watersheds for total nitrogen (TN) and total phosphorus (TP) loads as they transport from point of load reduction t...

  13. Attenuation of Frontostriatal Connectivity During Reward Processing Predicts Response to Psychotherapy in Major Depressive Disorder.

    Science.gov (United States)

    Walsh, Erin; Carl, Hannah; Eisenlohr-Moul, Tory; Minkel, Jared; Crowther, Andrew; Moore, Tyler; Gibbs, Devin; Petty, Chris; Bizzell, Josh; Smoski, Moria J; Dichter, Gabriel S

    2017-03-01

    There are few reliable predictors of response to antidepressant treatments. In the present investigation, we examined pretreatment functional brain connectivity during reward processing as a potential predictor of response to Behavioral Activation Treatment for Depression (BATD), a validated psychotherapy that promotes engagement with rewarding stimuli and reduces avoidance behaviors. Thirty-three outpatients with major depressive disorder (MDD) and 20 matched controls completed two runs of the monetary incentive delay task during functional magnetic resonance imaging after which participants with MDD received up to 15 sessions of BATD. Seed-based generalized psychophysiological interaction analyses focused on task-based connectivity across task runs, as well as the attenuation of connectivity from the first to the second run of the task. The average change in Beck Depression Inventory-II scores due to treatment was 10.54 points, a clinically meaningful response. Groups differed in seed-based functional connectivity among multiple frontostriatal regions. Hierarchical linear modeling revealed that improved treatment response to BATD was predicted by greater connectivity between the left putamen and paracingulate gyrus during reward anticipation. In addition, MDD participants with greater attenuation of connectivity between several frontostriatal seeds, and midline subcallosal cortex and left paracingulate gyrus demonstrated improved response to BATD. These findings indicate that pretreatment frontostriatal functional connectivity during reward processing is predictive of response to a psychotherapy modality that promotes improving approach-related behaviors in MDD. Furthermore, connectivity attenuation among reward-processing regions may be a particularly powerful endophenotypic predictor of response to BATD in MDD.

  14. Attenuation limits in longitudinal phononic crystals

    Science.gov (United States)

    Luschi, L.; Iannaccone, G.; Pieri, F.

    2017-12-01

    The acoustic attenuation inside the bandgaps is, together with the bandgap width, a fundamental design parameter for phononic-crystal-based systems. We discuss approximate expressions for the maximum attenuation inside the bandgaps of one-dimensional longitudinal phononic crystals and its dependence on the acoustic contrast and the fractional bandwidth. We provide different approximations at small and large fractional bandwidths, computed from the trace of the transmission matrix of the crystal elementary cell. We show that, for relatively small gaps, the attenuation is roughly proportional to the fractional bandwidth, in analogy with the flexural case. For larger gaps, a large attenuation can be obtained only for high (and possibly impractical) acoustic contrasts. Approximate expressions are validated through comparison with FEM results. We also derive asymptotic upper limits for the bandgap borders and show that high contrasts do not necessarily lead to wide bandgaps, a fact connected to geometrical phase inversion for the acoustic wave in the crystal. We finally compare the attenuation of flexural and longitudinal waves at a fixed fractional bandwidth and derive regions of optimum attenuation for the two propagation modes.

  15. What is Beyond Right/Left?

    DEFF Research Database (Denmark)

    Dyrberg, Torben Bech

    2009-01-01

    The article looks at New Labour's move beyond right/left in the mid/late 1990s, which is an occasion to spell out the nature of right/left and what it means for democracy. In contrast to both defenders and critics of this move I argue in the first part that right/left is not an empty label bound up...... with the cleavage-lines of industrial society, but that it is an orientational metaphor which is articulated with others-in/out, up/down and front/back-and that we are in the process of moving beyond the industrial society right/left prototype. The second part looks at where New Labour is heading when moving beyond...... right/left. I argue that the new hegemonic orientation is that of front/back, which designs political renewal as a response to the social changes cutting across the outdated lines of contestation of partisan politics. The democratic problem of this move lies in squeezing politics between technocratic...

  16. Left-Wing Extremism: The Current Threat

    Energy Technology Data Exchange (ETDEWEB)

    Karl A. Seger

    2001-04-30

    Left-wing extremism is ''alive and well'' both in the US and internationally. Although the current domestic terrorist threat within the U. S. is focused on right-wing extremists, left-wing extremists are also active and have several objectives. Leftist extremists also pose an espionage threat to U.S. interests. While the threat to the U.S. government from leftist extremists has decreased in the past decade, it has not disappeared. There are individuals and organizations within the U.S. who maintain the same ideology that resulted in the growth of left-wing terrorism in this country in the 1970s and 1980s. Some of the leaders from that era are still communicating from Cuba with their followers in the U.S., and new leaders and groups are emerging.

  17. A Case of Transient Global Amnesia with Small Left Putamen Infarction.

    Science.gov (United States)

    Yoshida, Kosuke

    2017-01-01

    A 67-year-old right-handed woman experienced a sudden anterograde and retrograde short-term memory deficit that recovered on the next day. Magnetic resonance imaging (MRI) showed a spotty high-intensity lesion in the left putamen in the diffusion-weighted and fluid-attenuated inversion recovery images. Transient global amnesia due to lacunar infarction of the left putamen was diagnosed. Transient global amnesia is characterized by a sudden onset of anterograde amnesia that disappears within 24 hours. The cause of transient global amnesia is still uncertain. Some studies with MRI showed small lesions in the hippocampus at 24-74 hours after the episode. These lesions disappear within several weeks. However, our case of transient global amnesia showed a small lesion in the left putamen, not the hippocampus. Some studies with functional MRI reported that the stratum plays an important role in short-term memory and cognitive function. This case showed only a left putamen lesion, which indicates that a putamen lesion can cause transient global amnesia. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  18. Left paraduodenal hernias; Hernias paraduodenales izquierdas

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Negrete, L.; Garcia-Lozano, J.; Sanchez, J. L.; Tejeiro, A.; Sala, J. [Hospital Valle del Nalon. Riano-Sama. Asturias (Spain)

    2002-07-01

    We report two cases of left paraduodenal internal hernias located in the fossa of Landzert that were diagnosed by CT. Internal hernias are an infrequent cause of acute abdomen, due to the intestinal sub occlusion they produce. Left paraduodenal hernias are responsible for about 50% of internal hernias. CT makes it possible to demonstrate the group of herniated loops between the stomach, fourth segment of the duodenum, descending colon, and tail of the pancreas. The identification of the loops in an atypical position together with displaced blood vessels (mesenteric vessels) and colon gives concerns on them a typical radiological semiology that makes them easily identifiable. (Author) 9 refs.

  19. Echocardiographic study of left atrial myxoma

    Directory of Open Access Journals (Sweden)

    Dalal J

    1979-01-01

    Full Text Available Four cases of left atrial myxoma were diagnosed pre-operatively by echocardiography. All cases showed characteristic echocardio-graphic features of variegated shadows behind the mitral valve in diastole and within the left atrium in systole. In two cases the my-xomas were surgically removed and confirmed on histology. In one case the post-operative echocardiogram showed complete dis-appearance of the abnormal shadows. Echocardiography is the most reliable method today for the diagnosis of a myxoma.

  20. Left Ventricular Pseudoaneurysm after Valve Replacement

    Directory of Open Access Journals (Sweden)

    Jun Ho Lee

    2015-02-01

    Full Text Available We present a case of left ventricular pseudoaneurysm, which is a very rare and fatal complication of cardiac procedures such as mitral valve replacement. A 55-year-old woman presented to the Department of Thoracic and Cardiovascular Surgery at Hanyang University Seoul Hospital with chest pain. Ten years prior, the patient had undergone double valve replacement due to aortic regurgitation and mitral steno-insufficiency. Surgical repair was successfully performed using a prosthetic pericardial patch via a left lateral thoracotomy.

  1. [Left-handedness and its clinical significance].

    Science.gov (United States)

    Cernácek, J

    1991-09-01

    The occurrence rate of lefthanded persons is estimated to range between 4-8% in the human population, according to the criteria used. On assessing pathological lefthandedness, the role of all factors affecting the development of a lefthanded subject has to be considered. There are morphological differences between left- and righthanded subjects. The differences in neuropsychologie performance of the right and left hemisphere are less pronounced in lefthanded than in righthanded persons. A relationship between lefthandedness and the occurrence of some pathological conditions has been established. On sociobiological evaluation it appears more appropriate to consider lefthandedness as a continuous quantitative manifestation of handedness rather than a separate biological variant of man.

  2. Left brain, right brain: facts and fantasies.

    Science.gov (United States)

    Corballis, Michael C

    2014-01-01

    Handedness and brain asymmetry are widely regarded as unique to humans, and associated with complementary functions such as a left-brain specialization for language and logic and a right-brain specialization for creativity and intuition. In fact, asymmetries are widespread among animals, and support the gradual evolution of asymmetrical functions such as language and tool use. Handedness and brain asymmetry are inborn and under partial genetic control, although the gene or genes responsible are not well established. Cognitive and emotional difficulties are sometimes associated with departures from the "norm" of right-handedness and left-brain language dominance, more often with the absence of these asymmetries than their reversal.

  3. [Hypertrophic cardiomyopathy with left ventricular dilatation].

    Science.gov (United States)

    Iwami, G; Miyazaki, Y; Matsuyama, K; Shida, M; Ooga, M; Furuta, Y; Ikeda, H; Toshima, H; Chiba, M; Koga, Y

    1988-06-01

    There is increasing interest in the notion that some patients with hypertrophic cardiomyopathy (HCM) progress to morphological and functional manifestations similar to those of dilated cardiomyopathy (DCM). From 165 consecutive patients with HCM, 20 patients with left ventricular dilatation (left ventricular end-diastolic diameter greater than or equal to 50 mm) were selected and designated as dilated HCM. The diagnosis of HCM was established in these patients either by detection of the classical form of HCM in family members, with 2-dimensional echocardiographic evidence of asymmetric septal hypertrophy (ASH; septal thickness greater than or equal to 15 mm and a ratio of septal to posterior wall thickness greater than or equal to 1.3); or by demonstrating myocardial fiber disarray in autopsy or biopsy samples. The clinical manifestations of these patients with dilated HCM were then compared with those of other forms of HCM without left ventricular dilatation; 1) 40 patients with hypertrophic obstructive cardiomyopathy (HOCM) who had resting intraventricular pressure gradients of 20 mmHg or more, 2) 80 patients with non-obstructive HCM, each of whom had ASH of the entire ventricular septum (typical ASH), and 3) 25 non-obstructive patients whose hypertrophy was localized to the apical region of the ventricular septum (apical ASH). Patients having apical hypertrophy with a spade-like configuration on the left ventriculogram were excluded from the study. Compared with HOCM and typical ASH groups, the patients with dilated HCM had family histories of significantly more frequent HCM and less frequent hypertension. The patients with dilated HCM also had significantly less fractional shortening (FS), decreased interventricular septal thickness, greater left ventricular end-diastolic pressure (LVEDP), and left ventricular dilatation. During the follow-up period (average: 3.5 years), seven patients (35%) with dilated HCM died; five from congestive heart failure (CHF), one

  4. New strict left bundle branch block criteria reflect left ventricular activation differences

    DEFF Research Database (Denmark)

    Emerek, Kasper Janus Grønn; Risum, Niels; Hjortshøj, Søren Pihlkjær

    2015-01-01

    AIMS: Pacing lead electrical delays and strict left bundle branch block (LBBB) criteria were assessed against cardiac resynchronization therapy (CRT) outcome. METHODS: Forty-nine patients with LBBB and QRS duration >130 milliseconds underwent CRT-implantation. Sensed right ventricular to left...

  5. Origin of left accessory hepatic artery from the left gastric artery in a ...

    African Journals Online (AJOL)

    We report a case of accessory hepatic artery that arose from the left gastric artery, entered the liver at an independent site from the porta hepatis to supply the left lobe of the liver. Transplantation of such livers with multi vascular pedicles may pose a challenge during anastomosis of these accessory hepatic arteries of the ...

  6. Comparison of non-attenuation corrected and attenuation corrected myocardial perfusion SPE

    Directory of Open Access Journals (Sweden)

    Hasan Raza

    2016-09-01

    Conclusion: This study demonstrates that CT based attenuation corrected Tc-99mm sestamibi SPECT myocardial perfusion imaging significantly improved the specificity of the RCA territory compared with non-attenuation corrected Tc-99mm sestamibi SPECT myocardial perfusion imaging in both genders irrespective of BMI.

  7. Focal Left Atrial Tachycardia in a Patient with Left Ventricular Noncompaction

    Directory of Open Access Journals (Sweden)

    Shailendra Singh

    2013-01-01

    Full Text Available Left ventricular noncompaction (LVNC is a rare disease caused by intrauterine failure of the myocardium to compact. The major clinical manifestations of LVNC include heart failure, ventricular tachyarrhythmia, thromboembolic event, and sudden deaths. Atrial arrhythmia usually seen is atrial fibrillation. We report a rare case of focal left atrial tachycardia in an 18-year-old patient who presented for evaluation of persistent tachycardia. Transthoracic echocardiogram showed severe systolic dysfunction and evidence of noncompaction of the left ventricle. A detailed review of ECG revealed the possibility of ectopic atrial tachycardia, most likely originating from the left side. Electrophysiology study showed sustained atrial tachycardia originating on the ridge anterior to the left sided pulmonary veins. A successful radiofrequency catheter ablation was performed at this site without any complications.

  8. Sound attenuation of tanker’s headphone

    Directory of Open Access Journals (Sweden)

    Rafał Młyński

    2015-03-01

    Full Text Available Crew of military vehicles, which is exposed to the noise associated with the engine running, as well as to shots from firearms, is equipped with headphones. The article presents the results of noise reduction by HC-98 headphone for steady state and impulsive noise. Two methods of research were used: sound attenuation measurements with participation of subjects and transmission loss measurements with the use of acoustic test fixture — device reflecting the properties of the head. Data for headphone were compared with noise reduction of two different, commonly used earmuffs (one light, the other strong limiting noise. The results indicated that measured headphone meets the requirements that allow for treating it as hearing protection, however, this headphone does not provide hearing protection such as earmuffs. Relatively low values of attenuation of acoustic impulses through the headphone versus the results for earmuffs were observed. Furthermore, in the case of headphone, in the frequency range 63-2000 Hz, the lower values of steady state noise sound attenuation, from about 2 up to even a 19 dB with respect to the attenuation of ear muffs were measured.[b]Keywords[/b]: acoustics, noise control, noise, sound attenuation

  9. Correlation of Electrocardiogram with Echocardiographic left ...

    African Journals Online (AJOL)

    In order to device a method of assessment of LVH that is objective, readily available, affordable and easily operable in the face of soaring cost of the more recent techniques, correlation of electrocardiographic (ECG) LVH parameters was done with echocardiographic (echo) left ventricular mass (LVM). ECG is objective ...

  10. Pathological Left-Handedness: An Explanatory Model.

    Science.gov (United States)

    Satz, Paul

    Reported was an explanatory conceptual model for pathological left-handedness (PLH) and related hypotheses, some of which could not be tested empirically due to lack of information. The model was reported to provide an explanation for the relationship between handedness and specific learning disability, and handedness and cerebral dominance for…

  11. Pathologic Left-Handedness: Does It Exist?

    Science.gov (United States)

    McManus, I. C.

    1983-01-01

    The concept of pathologic left-handedness is reviewed, from historical and empirical perspectives. It is suggested that there is no adequate evidence to justify its continued use, and the fact that the concept is still much used may be the result of a desire to restore lost symmetry to the brain. (Author/CL)

  12. Artificial, parallel, left-handed DNA helices.

    Science.gov (United States)

    Tian, Cheng; Zhang, Chuan; Li, Xiang; Li, Yingmei; Wang, Guansong; Mao, Chengde

    2012-12-19

    This communication reports an engineered DNA architecture. It contains multiple domains of half-turn-long, standard B-DNA duplexes. While each helical domain is right-handed and its two component strands are antiparallel, the global architecture is left-handed and the two component DNA strands are oriented parallel to each other.

  13. The New Arab Left and 1967

    DEFF Research Database (Denmark)

    Haugbølle, Sune

    2017-01-01

    In Arab political culture, the Naksa of 1967 had a number of watershed effects. Scholars have paid a lot of attention to the decline of secular Arab nationalism and the concurrent rise of Islamism. Much less research has been done on the way 1967 spurred radical left organizations, also known as ...

  14. Left dislocation: An exploration in linguistic typology

    African Journals Online (AJOL)

    Andrason, A, Dr

    In recent years, Left Dislocation (LD), and the related notion of constituent order, received much attention from both generative and cognitive-functional perspectives. The former has generally focused on formal properties of LD, while the latter has focused on the range of discourse-pragmatic functions associated ...

  15. Left ventricular mass: Myxoma or thrombus?

    Directory of Open Access Journals (Sweden)

    Monish S Raut

    2015-01-01

    Full Text Available Patient with embolic episode should always be evaluated for cardiac mass. Mass in left ventricular can be a myxoma or thrombus even in a normal functioning heart . In either case, mobile mass with embolic potential should be surgically resected.

  16. Left atrial myxoma with biventricular dysfunction.

    Science.gov (United States)

    Raut, Monish S; Shad, Sujay; Maheshwari, Arun

    2016-09-01

    Occurrence of left atrial myxoma with severe ventricular dysfunction without any obstructive coronary artery disease, as presented in our case, is very rare. It may be due to undiagnosed concomitant dilated cardiomyopathy or unknown cardiodepressant effect of myxoma which warrants further research. Copyright © 2016 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  17. Left-Right Symmetry at LHC

    CERN Document Server

    Maiezza, Alessio; Nesti, Fabrizio; Senjanovic, Goran

    2010-01-01

    We revisit the issue of the limit on the scale of Left-Right symmetry breaking. We focus on the minimal SU(2)_L x SU(2)_R x U(1)_B-L gauge theory with the seesaw mechanism and discuss the two possibilities of defining Left-Right symmetry as parity or charge conjugation. In the commonly adopted case of parity, we perform a complete numerical study of the quark mass matrices and the associated left and right mixing matrices without any assumptions usually made in the literature about the ratio of vacuum expectation values. We find that the usual lower limit on the mass of the right-handed gauge boson from the K mass difference, M_WR>2.5TeV, is subject to a possible small reduction due to the difference between right and left Cabibbo angles. In the case of charge conjugation the limit on M_WR is somewhat more robust. However, the more severe bounds from CP-violating observables are absent in this case. In fact, the free phases can also resolve the present mild discrepancy between the Standard Model and CP-violat...

  18. Clustered survival data with left-truncation

    DEFF Research Database (Denmark)

    Eriksson, Frank; Martinussen, Torben; Scheike, Thomas H.

    2015-01-01

    Left-truncation occurs frequently in survival studies, and it is well known how to deal with this for univariate survival times. However, there are few results on how to estimate dependence parameters and regression effects in semiparametric models for clustered survival data with delayed entry...

  19. Electrocardiographic features suggestive of a left. ventricular ...

    African Journals Online (AJOL)

    SA MEDICAL JOURNAL VOLUME 63 1 JANUARY 1983. 27. Electrocardiographic features suggestive of a left. ventricular' aneurysm following a high-velocity missile injury. A case report. T. H. DIAMOND, R. SMITH, D. P. MYBURGH, L. STEINGO. Summary. Electrocardiographic features suggestive of a transmural anterior ...

  20. Left Dislocation in Near-Native French

    Science.gov (United States)

    Donaldson, Bryan

    2011-01-01

    The present study is concerned with the upper limits of SLA--specifically, mastery of the syntax-discourse interface in successful endstate learners of second-language (L2) French (near-native speakers). Left dislocation (LD) is a syntactic means of structuring spoken French discourse by marking topic. Its use requires speakers to coordinate…

  1. Modern Democratic Left and Economic Crisis

    Directory of Open Access Journals (Sweden)

    Dubravko Radošević

    2011-01-01

    Full Text Available Political left, notably social democracy, implies acceptance of market economy and parliamentary democracy, as a political framework within which the interests of large sections of the population could be preserved. Does the modern political left have a chance to revive, after the global economic crisis? We believe it does. The core idea of social democracy is the idea of equality. It is the growing inequality that could help the return of social democracy. In Croatia, during transition, there was predominantly the process of neoliberalization, and the democratic left accepted a neoliberal economic agenda. Currently Croatia has a structural economic problem and deep recession. Due to the global crisis, the democratic left in Croatia should abandon economic neoliberalism. Macroeconomic policy decision-makers in Croatia should reject orthodox policies, and it is necessary to implement heterodox economic policies. There is an urgent need to achieve a new (postKeynesian consensus, a new combination of post-Keynesian economics and social democracy

  2. Left Dislocation: a typological overview | Westbury | Stellenbosch ...

    African Journals Online (AJOL)

    The Left Dislocation construction is a typologically universal phenomenon that has received detailed analysis, from both formal and functional perspectives, in a number of genetically and areally diverse languages. The present paper aims to provide a general overview of this cross-linguistic research with a concentration ...

  3. Topologically left invariant means on semigroup algebras

    Indian Academy of Sciences (India)

    Let M ( S ) be the Banach algebra of all bounded regular Borel measures on a locally compact Hausdorff semitopological semigroup with variation norm and convolution as multiplication. We obtain necessary and sufficient conditions for M ( S ) ∗ to have a topologically left invariant mean.

  4. Variants of the left aortic arch branches

    African Journals Online (AJOL)

    ORIGINAL ARTICLE. Variants of the left aortic arch branches. N Z Makhanya. MB ChB. R T Mamogale. MB 0113. N Khan. FCRaD (0). Department of Diagnostic Radiology. Medical University of Southern Africa. Abstract. The normal aorta has three branches from its arch, but variations in this pattern are not uncommon. Our.

  5. Left/Right Brains, Teammates in Learning.

    Science.gov (United States)

    Webb, Gertrude M.

    1983-01-01

    Left/right brain research and its implications for teachers of handicapped and nonhandicapped students are highlighted. Medical and psychological research in asymmetry and the related attitudinal changes toward brain functioning are reviewed. Respect for the functioning of each hemisphere and the need for the "teaming" of both are emphasized.…

  6. New Left Ideology: A Cross National Study.

    Science.gov (United States)

    Larsen, Knud S.; Lineback, Steve

    This study was undertaken to broaden the scope of the components of the "New Left" Scale, first developed by Christie et al. at Columbia College (1969), by including students from a U.S. university not known for its activism and responses given by a sample of Japanese college students. In short, U. S. and Japanese students both agreed…

  7. Radiative left-right Dirac neutrino mass

    Science.gov (United States)

    Ma, Ernest; Sarkar, Utpal

    2018-01-01

    We consider the conventional left-right gauge extension of the standard model of quarks and leptons without a scalar bidoublet. We study systematically how one-loop radiative Dirac neutrino masses may be obtained. In addition to two well-known cases from almost 30 years ago, we find two new scenarios with verifiable predictions.

  8. Left ventricular hypertrophy : virtuous intentions, malign consequences

    NARCIS (Netherlands)

    Pokharel, S; Sharma, UC; Pinto, YM

    Left ventricular hypertrophy (LVH) is currently the focus of intense cardiovascular research, with the resultant rapid evolution of novel concepts relating to its exceedingly complex pathophysiology. In addition to the alterations in signal transduction and disturbances in Ca2+ homeostasis, there

  9. Submitral Left Ventricular Aneurysm Associated with Thrombus

    African Journals Online (AJOL)

    2018-01-01

    Jan 1, 2018 ... Cuba. *Email: abera.hailu@gmail.com. ABSTRACT. BACKGROUND: Submitral left ventricular aneurysm is a rarely reported cardiac abnormality that is encountered commonly among blacks. So far, only one case has been reported from Ethiopia and. East Africa.Our aim is to report an interesting and rare ...

  10. Heterotaxy syndrome: This is the left, right?

    African Journals Online (AJOL)

    2015-12-09

    Dec 9, 2015 ... Licensee: AOSIS. OpenJournals. This work is licensed under the Creative Commons. Attribution License. Read online: Scan this QR code with your smart phone or mobile device to read online. .... persistent left-sided IVC (see the following video: https:// youtu.be/Q2ZQOrhCK9g).1. The abdominal aorta and.

  11. Diastolic Left Ventricular Dysfunction : A Clinical Appraisal

    NARCIS (Netherlands)

    Bronzwaer, J.G.F.

    2003-01-01

    Diastolic left ventricular (LV) distensibility is determined by the material properties of the LV wall and by LV geometry (i.e., LV shape, LV volume and LV wall thickness). These material properties are influenced both by the physical structure of the LV myocardium and by the dynamic process of

  12. Low dose 320-row CT for left atrium and pulmonary veins imaging--the feasibility study.

    Science.gov (United States)

    Yang, Lin; Xu, Lei; Yan, Zixu; Yu, Wei; Fan, Zhanming; Lv, Biao; Zhang, Zhaoqi

    2012-07-01

    To evaluate the feasibility of low dose target-CTA volume scan for left atrium and pulmonary veins imaging using 320-row CT. Forty-two patients (females 12, males 30; mean age 55.2 years; mean body mass index (BMI) 25.7 kg/m(2)) with persistent or intermittent atrial fibrillation before catheter ablation were enrolled in this study. Scan protocol was target-CTA volume scan under prospective ECG-gating. The target of the exposure was only set at 40% of the R-R interval (which was at the left atrium maximal volume). The exposure time was minimal setting (350 ms). Tube voltage 100 kV (BMI ≤ 25 kg/m(2)) or 120 kV (BMI>25 kg/m(2)), tube current 350-420 mA, and field of view of 180 mm × 180 mm-200 mm × 200 mm were used. The scanning range was from the level of the tracheal bifurcation to the diaphragm, and enabled to cover the left atrium and central pulmonary veins (120-140 mm). All of patients were divided into two groups according kV setting (100 kV and 120 kV). The image quality (good, moderate and poor) was evaluated by two reviewers. The CT-attenuation, image noise and contrast to noise ratio (CNR) of left atrium and every pulmonary vein branch were evaluated, respectively. The effective dose (ED) was calculated using a conversion coefficient for the chest 0.017. Of 42 patients, the image quality was good in 26 cases (62%) and moderate in 16 cases (38%). There was no statistical difference in the CT-attenuation and CNR of left atrium and central pulmonary veins between the two groups (P>0.05). The mean ED was 1.90 ± 0.19 mSv (range 1.57-2.25 mSv) in 100 kV group, and 3.83 ± 0.31 mSv (range 3.39-4.54 mSv) in 120 kV group. The low dose target-CTA volume scan is feasible in pulmonary veins and left atrium imaging using 320-row CT. Slim patients can be scanned at 100 kV setting without loss of image quality. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  13. Live attenuated vaccines for invasive Salmonella infections

    Science.gov (United States)

    Tennant, Sharon M.; Levine, Myron M.

    2015-01-01

    Salmonella enterica serovar Typhi produces significant morbidity and mortality worldwide despite the fact that there are licensed S. Typhi vaccines available. This is primarily due to the fact that these vaccines are not used in the countries that most need them. There is growing recognition that an effective invasive Salmonella vaccine formulation must also prevent infection due to other Salmonella serovars. We anticipate that a multivalent vaccine that targets the following serovars will be needed to control invasive Salmonella infections worldwide: S. Typhi, S. Paratyphi A, S. Paratyphi B (currently uncommon but may become dominant again), S. Typhimurium, S. Enteritidis and S. Choleraesuis (as well as other Group C Salmonella). Live attenuated vaccines are an attractive vaccine formulation for use in developing as well as developed countries. Here, we describe the methods of attenuation that have been used to date to create live attenuated Salmonella vaccines and provide an update on the progress that has been made on these vaccines. PMID:25902362

  14. Interleukin-2/Anti-Interleukin-2 Immune Complex Attenuates Cardiac Remodeling after Myocardial Infarction through Expansion of Regulatory T Cells

    Directory of Open Access Journals (Sweden)

    Zhipeng Zeng

    2016-01-01

    Full Text Available CD4+CD25+Foxp3+ regulatory T cells (Treg cells have protective effects in wound healing and adverse ventricular remodeling after myocardial infarction (MI. We hypothesize that the interleukin- (IL- 2 complex comprising the recombinant mouse IL-2/anti-IL-2 mAb (JES6-1 attenuates cardiac remodeling after MI through the expansion of Treg. Mice were subjected to surgical left anterior descending coronary artery ligation and treated with either PBS or IL-2 complex. The IL-2 complex significantly attenuates ventricular remodeling, as demonstrated by reduced infarct size, improved left ventricular (LV function, and attenuated cardiomyocyte apoptosis. The IL-2 complex increased the percentage of CD4+CD25+Foxp3+ Treg cells, which may be recruited to the infarcted heart, and decreased the frequencies of IFN-γ- and IL-17-producing CD4+ T helper (Th cells among the CD4+Foxp3− T cells in the spleen. Furthermore, the IL-2 complex inhibited the gene expression of proinflammatory cytokines as well as macrophage infiltrates in the infarcted myocardium and induced the differentiation of macrophages from M1 to M2 phenotype in border zone of infarcted myocardium. Our studies indicate that the IL-2 complex may serve as a promising therapeutic approach to attenuate adverse remodeling after MI through expanding Treg cells specifically.

  15. Melatonin attenuates postmyocardial infarction injury via increasing Tom70 expression.

    Science.gov (United States)

    Pei, Hai-Feng; Hou, Juan-Ni; Wei, Fei-Peng; Xue, Qiang; Zhang, Fan; Peng, Cheng-Fei; Yang, Yi; Tian, Yue; Feng, Juan; Du, Jin; He, Lei; Li, Xiu-Chuan; Gao, Er-He; Li, De; Yang, Yong-Jian

    2017-01-01

    Mitochondrial dysfunction leads to reactive oxygen species (ROS) overload, exacerbating injury in myocardial infarction (MI). As a receptor for translocases in the outer mitochondrial membrane (Tom) complex, Tom70 has an unknown function in MI, including melatonin-induced protection against MI injury. We delivered specific small interfering RNAs against Tom70 or lentivirus vectors carrying Tom70a sequences into the left ventricles of mice or to cultured neonatal murine ventricular myocytes (NMVMs). At 48 h post-transfection, the left anterior descending coronary arteries of mice were permanently ligated, while the NMVMs underwent continuous hypoxia. At 24 h after ischemia/hypoxia, oxidative stress was assessed by dihydroethidium and lucigenin-enhanced luminescence, mitochondrial damage by transmission electron microscopy and ATP content, and cell apoptosis by terminal deoxynucleotidyl transferase dUTP nick-end labeling and caspase-3 assay. At 4 weeks after ischemia, cardiac function and fibrosis were evaluated in mice by echocardiography and Masson's trichrome staining, respectively. Ischemic/hypoxic insult reduced Tom70 expression in cardiomyocytes. Tom70 downregulation aggravated post-MI injury, with increased mitochondrial fragmentation and ROS overload. In contrast, Tom70 upregulation alleviated post-MI injury, with improved mitochondrial integrity and decreased ROS production. PGC-1α/Tom70 expression in ischemic myocardium was increased with melatonin alone, but not when combined with luzindole. Melatonin attenuated post-MI injury in control but not in Tom70-deficient mice. N-acetylcysteine (NAC) reversed the adverse effects of Tom70 deficiency in mitochondria and cardiomyocytes, but at a much higher concentration than melatonin. Our findings showed that Tom70 is essential for melatonin-induced protection against post-MI injury, by breaking the cycle of mitochondrial impairment and ROS generation. © 2016 John Wiley & Sons A/S. Published by John Wiley

  16. Prevalence and characteristics of left atrial tachycardia following left atrial catheter ablation.

    Science.gov (United States)

    Hashimoto, Toru; Tada, Hiroshi; Naito, Shigeto; Miyaji, Kohei; Yamada, Minoru; Tadokoro, Kazuyoshi; Kaseno, Kenichi; Oshima, Shigeru; Taniguchi, Koichi

    2007-01-01

    Left atrial tachycardia (AT) is a complication of left atrial catheter ablation (LACA) of atrial fibrillation (AF). However, its prevalence and characteristics have not been sufficiently clarified. We divided 121 patients who underwent LACA into 2 groups based on the results of AT occurrence after LACA (follow-up period; 12 +/- 7 months): an AT+ group and AT- group. New-onset left AT occurred in 30 patients (25%) 31 +/- 51 days after LACA. Among the 26 patients with an early onset of AT, 4 underwent a second ablation for AT, and 21 became free of AT within 6 months without a repeat ablation procedure. Among the 4 patients with a late onset of AT (> 2 months after the LACA), the tachycardia remitted without a repeat ablation procedure in a single patient within 6 months. Among 71 patients who underwent LACA with additional ablation lines, 22 (31%) developed new-onset left AT. Among 50 patients who underwent LACA alone, 8 (16%) developed new-onset left AT (P = 0.02). New-onset left AT is a frequent complication of LACA for AF, especially in men and in patients with a low left ventricular ejection fraction. Early (< 2 months) onset AT does not require a repeat ablation because it often represents a transient phenomenon and disappears spontaneously.

  17. [Usefulness of left atrial diametres and volumes for the evaluation of left ventricular diastolic function].

    Science.gov (United States)

    Vizzardi, Enrico; Bonadei, Ivano; Teli, Melissa; Caretta, Giorgio; Maiandi, Cristian; Madureri, Alberto; Bordonali, Tania; Chiari, Ermanna; Raddino, Riccardo; Cas, Livio Dei

    2009-06-01

    The diastolic function of the left ventricle is a main point of the physiological adaptations of the cardiovascular system to the various situations. Evaluation of left atrium diameter change during diastole and left atrial volume and their possible correlation with different left ventricular diastolic filling pattern. Ninety patients with echocardiographically determined diastolic dysfunction and eighty healthy volunteers were included in the study. We measured left atrium emptying fraction (LAEF), defined as ratio of end-diastolic left atrial diameter to end-systolic diameter and left atrial volume. Mitral flow pulsed wave velocities were recorded. E, A, E/A, deceleration time of early diastolic filling, isovolumetric relaxation time were measured. Pulmonary vein S, D and atrial reversal velocities and tissue Doppler imaging of E' and A' mitral anular velocities were obtained. LAEF was found 0.6 +/- 0.4 (mean SE) in the control group, 0.81 +/- 0.04 in pseudonormal pattern (P E group (P E pattern group). LAEF and atrial volume are a new and practical methods for the differentiation of the normal-pseudonormal mitral flow pattern, in particular in setting without new ultrasound technologies.

  18. Left hemisphere regions are critical for language in the face of early left focal brain injury.

    Science.gov (United States)

    Raja Beharelle, Anjali; Dick, Anthony Steven; Josse, Goulven; Solodkin, Ana; Huttenlocher, Peter R; Levine, Susan C; Small, Steven L

    2010-06-01

    A predominant theory regarding early stroke and its effect on language development, is that early left hemisphere lesions trigger compensatory processes that allow the right hemisphere to assume dominant language functions, and this is thought to underlie the near normal language development observed after early stroke. To test this theory, we used functional magnetic resonance imaging to examine brain activity during category fluency in participants who had sustained pre- or perinatal left hemisphere stroke (n = 25) and in neurologically normal siblings (n = 27). In typically developing children, performance of a category fluency task elicits strong involvement of left frontal and lateral temporal regions and a lesser involvement of right hemisphere structures. In our cohort of atypically developing participants with early stroke, expressive and receptive language skills correlated with activity in the same left inferior frontal regions that support language processing in neurologically normal children. This was true independent of either the amount of brain injury or the extent that the injury was located in classical cortical language processing areas. Participants with bilateral activation in left and right superior temporal-inferior parietal regions had better language function than those with either predominantly left- or right-sided unilateral activation. The advantage conferred by left inferior frontal and bilateral temporal involvement demonstrated in our study supports a strong predisposition for typical neural language organization, despite an intervening injury, and argues against models suggesting that the right hemisphere fully accommodates language function following early injury.

  19. Two-dimensional dynamic fluid bowtie attenuators

    OpenAIRE

    Hermus, James R.; Szczykutowicz, Timothy P.

    2016-01-01

    Fluence field modulated (FFM) CT allows for improvements in image quality and dose reduction. To date, only one-dimensional modulators have been proposed, as the extension to two-dimensional (2-D) modulation is difficult with solid-metal attenuation-based fluence field modulated designs. This work proposes to use liquid and gas to attenuate the x-ray beam, as unlike solids, these materials can be arranged allowing for 2-D fluence modulation. The thickness of liquid and the pressure for a give...

  20. PICTORIAL ESSAY Is anomalous origin of the left vertebral artery ...

    African Journals Online (AJOL)

    The incidence of anomalous origin of the left vertebral artery from the aortic arch ranges between 1% and 5.8%.1,2 This anomaly has important implications for thoracic surgery and interventional procedures. The left vertebral artery may originate from: • the left common carotid artery. • the root of the left subclavian artery ...

  1. RELATIONSHIP OF LEFT VENTRICULAR SIZE TO LEFT ATRIAL AND LEFT ATRIAL APPENDAGE SIZE IN SINUS RHYTHM PATIENTS WITH DILATED CARDIOMYOPATHY

    Science.gov (United States)

    Bakalli, Aurora; Georgievska-Ismail, Ljubica; Musliu, Nebi; Koçinaj, Dardan; Gashi, Zaim; Zeqiri, Nexhmi

    2012-01-01

    Introduction: Thromboembolic events are a frequent cause of mortality in patients with congestive heart failure. The aim of or study was to evaluate the relationship of left ventricular end diastolic diameter (LVEDD) to left atrial (LA) size and left atrial appendage (LAA) size in patients with dilated cardiomyopathy in sinus rhythm, as well as to determine the prevalence of thrombi in LV and LA /LAA. Methods: This was a prospective cross-sectional study, conducted from December 2009 until December 2011. The study included 95 patients with dilated cardiomyopathy in sinus rhythm. Patients with swallowing problems, acute myocardial infarction, atrial fibrillation/flatter, severe systolic dysfunction, and/or patients who were taking oral anticoagulation therapy were excluded. Results: Mean patient age was 58.6 ± 12.2 years and 68.4% were men. Mean LVEDD of our population was 66.5 ± 6.5 mm, while mean LA atrium, LA volume and LAA maximal area were 46 ± 5.1 mm, 87.2 ± 38.7 cm3 and 4.7 ± 1.2 cm2, respectively. LA diameter (p<0.001) and LAA maximal area (p=0.01) showed to be independent predictors of LV size. LV thrombus was detected in 13 (13.7%) patients, while LAA thrombus in 46 (48.4%) patients of our study population. Conclusions: In conclusion, dilated LV size is associated with enlarged LA and LAA size. On the other hand, dilation of LV, LA and LAA is related to high prevalence of left chamber cardiac thrombi. PMID:23322961

  2. Relationship of left ventricular size to left atrial and left atrial appendage size in sinus rhythm patients with dilated cardiomyopathy.

    Science.gov (United States)

    Bakalli, Aurora; Georgievska-Ismail, Ljubica; Musliu, Nebi; Koçinaj, Dardan; Gashi, Zaim; Zeqiri, Nexhmi

    2012-06-01

    Thromboembolic events are a frequent cause of mortality in patients with congestive heart failure. The aim of or study was to evaluate the relationship of left ventricular end diastolic diameter (LVEDD) to left atrial (LA) size and left atrial appendage (LAA) size in patients with dilated cardiomyopathy in sinus rhythm, as well as to determine the prevalence of thrombi in LV and LA /LAA. This was a prospective cross-sectional study, conducted from December 2009 until December 2011. The study included 95 patients with dilated cardiomyopathy in sinus rhythm. Patients with swallowing problems, acute myocardial infarction, atrial fibrillation/flatter, severe systolic dysfunction, and/or patients who were taking oral anticoagulation therapy were excluded. Mean patient age was 58.6 ± 12.2 years and 68.4% were men. Mean LVEDD of our population was 66.5 ± 6.5 mm, while mean LA atrium, LA volume and LAA maximal area were 46 ± 5.1 mm, 87.2 ± 38.7 cm(3) and 4.7 ± 1.2 cm(2), respectively. LA diameter (p<0.001) and LAA maximal area (p=0.01) showed to be independent predictors of LV size. LV thrombus was detected in 13 (13.7%) patients, while LAA thrombus in 46 (48.4%) patients of our study population. In conclusion, dilated LV size is associated with enlarged LA and LAA size. On the other hand, dilation of LV, LA and LAA is related to high prevalence of left chamber cardiac thrombi.

  3. Comparison of MR-based attenuation correction vs. CT-based attenuation correction of Whole Body PET/MR imaging

    Science.gov (United States)

    Izquierdo-Garcia, David; Sawiak, Stephen J.; Knesaurek, Karin; Narula, Jagat; Fuster, Valentin; Machac, Joseph; Fayad, Zahi A.

    2014-01-01

    Purpose The objective of this paper was to evaluate the performance of the built-in MR-based attenuation correction method (MRAC) included in the combined whole-body Ingenuity TF PET/MR scanner and compare it to the gold standard CT-based attenuation correction (CTAC). Methods Twenty-six patients undergoing clinical whole body FDG-PET/CT imaging were subsequently scanned on the PET/MR (mean delay 100min). Patients were separated in two groups: alpha group (N=14) with no MR coils during PET/MR imaging and beta group (N=12) including MR coils (Neuro-Vascular, Spine, Cardiac or Torso coils). All images were coregistered to the same space (PET/MR). Voxel- and region-based (10 regions of interest, ROIs) comparisons were made between the 2 PET images from PET/MR: using MRAC and CTAC. Additional comparison of lesions performed by an experienced clinician was also reported. Results Body mass index (BMI) and lung density showed significant differences between alpha and beta groups. Right vs. left lung density was also significantly different within each group. Overall the beta group (with coils) presented higher MRAC PET values than the alpha group when compared to the CTAC (alpha: −0.2±33.6%, R2=0.98, p<0.001, beta: 10.31±69.86%, R2=0.97, p<0.001). Conclusion In comparison to CTAC, PET values with MRAC method were underestimated by less than 10% on average, although some ROIs and lesions do differ by more (such as spine, lung or heart). The beta group (with coils) showed increased overall PET quantification as well as increased variability when compared to the alpha group (no coils). PET reconstructed with MRAC showed some differences when compared to PET reconstructed with CTAC, mostly due to air pockets, metallic implants and attenuation differences in big bone areas (such as pelvis and spine) due to the segmentation limitation of the MRAC method. PMID:24652234

  4. Left bronchial artery arising from a replaced left hepatic artery in a patient with massive hemoptysis

    Energy Technology Data Exchange (ETDEWEB)

    Khil, Eun Kyung; Lee, Jae Myung [Dept. of Radiology, Soonchunhyang University College of Medicine, Bucheon Hospital, Bucheon (Korea, Republic of)

    2015-09-15

    A 70-year-old man with a 3-year history of bronchiectasis presented with massive hemoptysis that had lasted for 3 days. In our attempt to perform bronchial artery embolization, upper abdominal angiography was required to locate the left bronchial artery, which in this case was of anomalous origin, arising from a replaced left hepatic artery, which arose from the left gastric artery-a very unusual anatomical variant. We performed embolization with polyvinyl alcohol particles, and the patient's symptoms resolved completely, with no additional complications after conservative treatment.

  5. Detection of significant stenosis in the left anterior descending artery by 'virtual myocardial perfusion' bolus tracking, 320 slice computed tomography.

    Science.gov (United States)

    Takaoka, Hiroyuki; Funabashi, Nobusada; Fujimoto, Yoshihide; Kobayashi, Yoshio

    2014-12-20

    We used bolus-tracking CT-images, which are usually used only to detect contrast-material in target organs for optimal-starting of acquisition, as virtual first pass myocardial perfusion images. Retrospective-analysis of 14 patients (10 male, 63 ± 10 years) diagnosed with ≥ 75% stenosis confined to left-anterior-descending-artery (LAD) (7 patients, Group-1) or insignificant stenosis of any coronary artery (7 patients Group-2) diagnosed using invasive-coronary-angiograms (ICA) and enhanced 320-slice-CT within 3-months and without incident between examinations. Bolus-tracking CT-images were acquired at mid-level left-ventricle (LV) until CT-attenuation of descending-aorta increased to 200 HU. We measured CT-attenuation (HU) in the LV anterior-wall (AW), the basal inter-ventricular-septum (BIVS), and LV basal lateral-wall (BLW) in end-systole using both bolus-tracking images and routine, enhanced, early-phase CT-images. In the bolus-tracking images, the Group-1 LV AW, BIVS, BLW CT-attenuation and ratio of LV AW CT attenuation to the average of BIVS and BLW were 36 ± 7HU, 62 ± 11HU, 58 ± 25HU, and 0.6 ± 0.1 respectively. In Group-2, they were 53 ± 14HU, 56 ± 9HU, 54 ± 15HU, and 1.0 ± 0.3 respectively. LV AW CT attenuation and the ratio of LV AW CT values to the average of BIVS and BLW, were significantly lower in Group-1 (both P BLW and without the need for drugs, exercise or additional radiation-exposure. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  6. Correlation of the myocardial perfusion corrected by attenuation with the coronariography. Preliminary results; Correlacion de la perfusion miocardica corregida por atenuacion con la coronariografia

    Energy Technology Data Exchange (ETDEWEB)

    Garcia C, S.E.; Garcia O, R. [Servicio de Medicina Nuclear, Centro Medico ABC, Campis Observatorio, IAP (Mexico)

    2005-07-01

    The attenuation that suffers the radiation in the soft tissues of the hinders the appropriate interpretation of the myocardial perfusion studies, for what have been implemented attenuation correction systems to reduce the attenuation for soft tissues and to provide myocardial perfusion images more accurate in the diagnosis of coronary illness. The objective was to evaluate the utility of an attenuation correction system (with source of Gadolinium 153) to minimize the devices that look like true defects of myocardial perfusion, caused by soft tissues (mammary tissue, thoracic wall, abdomen, left hemi diaphragm), and to compare those interpretations of the studies with the interpretations of the corresponding coronariographies. The method consists of 95 electronic files which were revised with the concept of heart catheterization, being identified 20 patients from the masculine sex to those that underwent coronariography among May 1999 and December 2002, and that they had study of myocardial perfusion in a maximum period of 3 months foresaw to the invasive procedure. (Author)

  7. Novel Toll-like receptor-4 deficiency attenuates trastuzumab (Herceptin) induced cardiac injury in mice.

    Science.gov (United States)

    Yousif, Nasser Ghaly; Al-Amran, Fadhil G

    2011-10-14

    Cardiac inflammation and generation of oxidative stress are known to contribute to trastuzumab (herceptin) induced cardiac toxicity. Toll-like receptors (TLRs) are a part of the innate immune system and are involved in cardiac stress reactions. Since TLR4 might play a relevant role in cardiac inflammatory signaling, we investigated whether or not TLR4 is involved in trastuzumab induced cardiotoxicity. Seven days after a single injection of herceptin (2 mg/kg; i.p.), left ventricular pressure volume loops were measured in HeN compotent (TLR4+/+) and HeJ mutant (TLR4-/-) treated with trastuzumab and control mice. Immunofluorescent staining for monocyte infiltration and analyses of plasma by (ELISAs) for different chemokines including: MCP-1and tumor necrosis factor-α (TNF-α), Western immunoblotting assay for ICAM-1, and used troponin I for cardiac injury marker. Trastuzumab injection resulted in an impairment of left ventricular function in TLR-4 competent (HeN), in contrast TLR4-/- trastuzumab mice showed improved left ventricular function EF%, CO; p < 0.05, attenuation of mononuclear cell infiltration in TLR4 -/-; p < 0.05 vs.TLR-4 competent (HeN), reduced level of cytokines TNF-α, MCP-1 and ICAM-1 expression in TLR4-/-, marked reduction of myocardial troponin-I levels in TLR4-deficient mice. Data are presented as means ± SE; n = 8 in each group p < 0.05 vs.TLR-4 competent (HeN). Treatment with trastuzumab induces an inflammatory response that contributes to myocardial tissue TLR4 mediates chemokine expression (TNF-α, MCP-1and ICAM-1), so in experimental animals TLR4 deficiency improves left ventricular function and attenuates pathophysiological key mechanisms in trastuzumab induced cardiomyopathy.

  8. Myocardial infarction and left ventricular remodeling: results of the CEDIM trial. Carnitine Ecocardiografia Digitalizzata Infarto Miocardico.

    Science.gov (United States)

    Colonna, P; Iliceto, S

    2000-02-01

    Left ventricular dilatation after acute myocardial infarction (MI) is a powerful predictor of progressive functional deterioration, culminating in heart failure and death. The most important determinants of post-MI left ventricular remodeling are the size of the infarct, the degree of residual stenosis in the infarct-related artery, and the viability of the infarct zone. In addition to reperfusion therapy and angiotensin-converting enzyme inhibition, metabolic intervention with L-carnitine may represent a therapeutic approach for preventing left ventricular dilatation and preserving cardiac function. Ongoing studies with early metabolic intervention with carnitine in the acute phase of infarction may prove successful in protecting the microcirculation against ischemic damage and enhancing its ability to respond to blood flow resumption. The results of the multicenter, randomized, double-blind Carnitine Ecocardiografia Digitalizzata Infarto Miocardico (CEDIM) trial suggest that the early and long-term administration of L-carnitine attenuates progressive left ventricular dilatation after acute anterior MI. Results show significant, consistent reductions in end-diastolic volume and end-systolic volume in patients who received L-carnitine compared with placebo. The ongoing CEDIM-2 trial (projected 4000 patients with acute MI) will assess the efficacy of L-carnitine in reducing the combined incidence of death and heart failure at 6 months. In addition to standard reperfusion therapy and angiotensin-converting enzyme inhibition, metabolic intervention with L-carnitine may be a therapeutic approach for preventing left ventricular dilatation and preserving cardiac function by limiting infarct size, decreasing residual stenosis in the infarct-related artery, and increasing viability of the infarct zone.

  9. Dyscalculia, Dysgraphia, and Left-Right Confusion from a Left Posterior Peri-Insular Infarct

    Science.gov (United States)

    Bhattacharyya, S.; Cai, X.; Klein, J. P.

    2014-01-01

    The Gerstmann syndrome of dyscalculia, dysgraphia, left-right confusion, and finger agnosia is generally attributed to lesions near the angular gyrus of the dominant hemisphere. A 68-year-old right-handed woman presented with sudden difficulty completing a Sudoku grid and was found to have dyscalculia, dysgraphia, and left-right confusion. Magnetic resonance imaging (MRI) showed a focus of abnormal reduced diffusivity in the left posterior insula and temporoparietal operculum consistent with acute infarct. Gerstmann syndrome from an insular or peri-insular lesion has not been described in the literature previously. Pathological and functional imaging studies show connections between left posterior insular region and inferior parietal lobe. We postulate that the insula and operculum lesion disrupted key functional networks resulting in a pseudoparietal presentation. PMID:24817791

  10. Effects of novel oral anticoagulants on left atrial and left atrial appendage thrombi: an appraisal.

    Science.gov (United States)

    Marsico, Fabio; Cecere, Milena; Parente, Antonio; Paolillo, Stefania; de Martino, Fabiana; Dellegrottaglie, Santo; Trimarco, Bruno; Perrone Filardi, Pasquale

    2017-02-01

    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and predisposes to an increased risk of thromboembolic events. Patients affected by AF exhibit an increased risk of stroke compared with those in sinus rhythm, with the most common location of thrombi in the left atrial appendage. Until 2009, warfarin and other vitamin K antagonists were the only class of oral anticoagulants available. More recently, dabigatran, rivaroxaban, apixaban, and edoxaban have been approved by regulatory authorities for prevention of stroke in patients with non-valvular AF. Few data are available about the efficacy of novel oral anticoagulants for the treatment of left atrial and left atrial appendage thrombosis. Aim of this review is to summarize available evidence regarding the effectiveness of novel oral anticoagulants on left atrial appendage thrombosis.

  11. Metastatic Testicular Cancer to Left Atrium via the Left Inferior Pulmonary Vein: A Case Report

    Directory of Open Access Journals (Sweden)

    Shital Vachhani

    2017-03-01

    Full Text Available Testicular cancer is one of the most common cancers diagnosed in young men. Frequent sites of metastasis include the retroperitoneum, lungs, liver, brain, and bone. Intracardiac metastasis has also been described. An 18-year-old boy with a history of mixed testicular germ cell tumor presented to our institution for surgical resection of his metastatic disease. Intraoperative transesophageal echocardiography during his surgery confirmed a tumor thrombus into the left atrium coming from the left pulmonary vein. We report a case of metastatic testicular cancer with rare tumor extension from the left inferior pulmonary vein into the left atrium. Perioperative transesophageal echocardiography was necessary to aid intraoperative diagnosis and confirmation of the intracardiac tumor, providing data to guide surgical strategy.

  12. Dyscalculia, dysgraphia, and left-right confusion from a left posterior peri-insular infarct.

    Science.gov (United States)

    Bhattacharyya, S; Cai, X; Klein, J P

    2014-01-01

    The Gerstmann syndrome of dyscalculia, dysgraphia, left-right confusion, and finger agnosia is generally attributed to lesions near the angular gyrus of the dominant hemisphere. A 68-year-old right-handed woman presented with sudden difficulty completing a Sudoku grid and was found to have dyscalculia, dysgraphia, and left-right confusion. Magnetic resonance imaging (MRI) showed a focus of abnormal reduced diffusivity in the left posterior insula and temporoparietal operculum consistent with acute infarct. Gerstmann syndrome from an insular or peri-insular lesion has not been described in the literature previously. Pathological and functional imaging studies show connections between left posterior insular region and inferior parietal lobe. We postulate that the insula and operculum lesion disrupted key functional networks resulting in a pseudoparietal presentation.

  13. Dyscalculia, Dysgraphia, and Left-Right Confusion from a Left Posterior Peri-Insular Infarct

    Directory of Open Access Journals (Sweden)

    S. Bhattacharyya

    2014-01-01

    Full Text Available The Gerstmann syndrome of dyscalculia, dysgraphia, left-right confusion, and finger agnosia is generally attributed to lesions near the angular gyrus of the dominant hemisphere. A 68-year-old right-handed woman presented with sudden difficulty completing a Sudoku grid and was found to have dyscalculia, dysgraphia, and left-right confusion. Magnetic resonance imaging (MRI showed a focus of abnormal reduced diffusivity in the left posterior insula and temporoparietal operculum consistent with acute infarct. Gerstmann syndrome from an insular or peri-insular lesion has not been described in the literature previously. Pathological and functional imaging studies show connections between left posterior insular region and inferior parietal lobe. We postulate that the insula and operculum lesion disrupted key functional networks resulting in a pseudoparietal presentation.

  14. Touch Attenuates Infants' Physiological Reactivity to Stress

    Science.gov (United States)

    Feldman, Ruth; Singer, Magi; Zagoory, Orna

    2010-01-01

    Animal studies demonstrate that maternal touch and contact regulate infant stress, and handling during periods of maternal deprivation attenuates the stress response. To measure the effects of touch on infant stress reactivity during simulated maternal deprivation, 53 dyads were tested in two paradigms: still-face (SF) and still-face with maternal…

  15. Coffee Consumption Attenuates Insulin Resistance and Glucose ...

    African Journals Online (AJOL)

    olayemitoyin

    J. Physiol. Sci. 28(December 2013) 179–185 www.njps.com.ng. Coffee Consumption Attenuates Insulin Resistance and Glucose. Intolerance in Rats fed on High-Sucrose Diet. Morakinyo AO*, Adekunbi DA, Dada KA and Adegoke OA. Department of Physiology, College of Medicine of the University of Lagos, Lagos. Nigeria.

  16. Electrically tunable hot-silicon terahertz attenuator

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Minjie [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Vajtai, Robert; Ajayan, Pulickel M. [Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Kono, Junichiro, E-mail: kono@rice.edu [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States)

    2014-10-06

    We have developed a continuously tunable, broadband terahertz attenuator with a transmission tuning range greater than 10{sup 3}. Attenuation tuning is achieved electrically, by simply changing the DC voltage applied to a heating wire attached to a bulk silicon wafer, which controls its temperature between room temperature and ∼550 K, with the corresponding free-carrier density adjusted between ∼10{sup 11 }cm{sup −3} and ∼10{sup 17 }cm{sup −3}. This “hot-silicon”-based terahertz attenuator works most effectively at 450–550 K (corresponding to a DC voltage variation of only ∼7 V) and completely shields terahertz radiation above 550 K in a frequency range of 0.1–2.5 THz. Both intrinsic and doped silicon wafers were tested and demonstrated to work well as a continuously tunable attenuator. All behaviors can be understood quantitatively via the free-carrier Drude model taking into account thermally activated intrinsic carriers.

  17. Coffee Consumption Attenuates Insulin Resistance and Glucose ...

    African Journals Online (AJOL)

    Coffee Consumption Attenuates Insulin Resistance and Glucose Intolerance in Rats fed on High-Sucrose Diet. ... Summary: Several epidemiological evidences indicate that consumption of coffee is associated with a lower risk of type 2 diabetes mellitus (T2DM) however; there is dearth of experimental data to support these ...

  18. Ultrasonic attenuation in rare-earth monoarsenides

    Indian Academy of Sciences (India)

    The toughness/fracture (G/BT) ratio is greater than 0.60, which implies that XAs compounds are brittle at room temperature. Further, the Debye temperature is computed using Debye average velocity as the input parameter. It helps in the characterization of lattice vibrations of a solid. In this work, ultrasonic attenuation due to ...

  19. GPR measurements of attenuation in concrete

    Science.gov (United States)

    Eisenmann, David; Margetan, Frank J.; Pavel, Brittney

    2015-03-01

    Ground-penetrating radar (GPR) signals from concrete structures are affected by several phenomenon, including: (1) transmission and reflection coefficients at interfaces; (2) the radiation patterns of the antenna(s) being used; and (3) the material properties of concrete and any embedded objects. In this paper we investigate different schemes for determining the electromagnetic (EM) attenuation of concrete from measured signals obtained using commercially-available GPR equipment. We adapt procedures commonly used in ultrasonic inspections where one compares the relative strengths of two or more signals having different travel paths through the material of interest. After correcting for beam spread (i.e., diffraction), interface phenomena, and equipment amplification settings, any remaining signal differences are assumed to be due to attenuation thus allowing the attenuation coefficient (say, in dB of loss per inch of travel) to be estimated. We begin with a brief overview of our approach, and then discuss how diffraction corrections were determined for our two 1.6 GHz GPR antennas. We then present results of attenuation measurements for two types of concrete using both pulse/echo and pitch/catch measurement setups.

  20. Anethum Graveolens Linn (Umbelliferae) Extract Attenuates Stress ...

    African Journals Online (AJOL)

    Anethum Graveolens Linn (Umbelliferae) Extract Attenuates Stress-induced Urinary Biochemical Changes and Improves Cognition in Scopolamineinduced Amnesic Rats. ... Conclusion: The aqueous extract of A. graveolens exhibited significant anti-stress, antioxidant and memory enhancing activities. The study provides a ...

  1. GPR measurements of attenuation in concrete

    Energy Technology Data Exchange (ETDEWEB)

    Eisenmann, David, E-mail: djeisen@cnde.iastate.edu; Margetan, Frank J., E-mail: djeisen@cnde.iastate.edu; Pavel, Brittney, E-mail: djeisen@cnde.iastate.edu [Center for Nondestructive Evaluation, Iowa State University, 1915 Scholl Road, Ames, IA 50011-3042 (United States)

    2015-03-31

    Ground-penetrating radar (GPR) signals from concrete structures are affected by several phenomenon, including: (1) transmission and reflection coefficients at interfaces; (2) the radiation patterns of the antenna(s) being used; and (3) the material properties of concrete and any embedded objects. In this paper we investigate different schemes for determining the electromagnetic (EM) attenuation of concrete from measured signals obtained using commercially-available GPR equipment. We adapt procedures commonly used in ultrasonic inspections where one compares the relative strengths of two or more signals having different travel paths through the material of interest. After correcting for beam spread (i.e., diffraction), interface phenomena, and equipment amplification settings, any remaining signal differences are assumed to be due to attenuation thus allowing the attenuation coefficient (say, in dB of loss per inch of travel) to be estimated. We begin with a brief overview of our approach, and then discuss how diffraction corrections were determined for our two 1.6 GHz GPR antennas. We then present results of attenuation measurements for two types of concrete using both pulse/echo and pitch/catch measurement setups.

  2. Microwave attenuation with composite of copper microwires

    Energy Technology Data Exchange (ETDEWEB)

    Gorriti, A.G.; Marin, P. [Instituto de Magnetismo Aplicado, (UCM-ADIF-CSIC) and Departamento de Fisica de Materiales (UCM). P.O. Box 155, Las Rozas, Madrid 28230 (Spain); Cortina, D. [Micromag S.L., Las Rozas, Madrid 28230 (Spain); Hernando, A., E-mail: antonio.hernando@adif.e [Instituto de Magnetismo Aplicado, (UCM-ADIF-CSIC) and Departamento de Fisica de Materiales (UCM). P.O. Box 155, Las Rozas, Madrid 28230 (Spain); Micromag S.L., Las Rozas, Madrid 28230 (Spain)

    2010-05-15

    It is shown that copper microwires composite media attenuates microwave reflection of metallic surfaces. We show how the distance to the metallic surface, as well as the length and volume fraction of microwires, determine the frequency of maximum absorption and the return loss level. Furthermore, we were able to fit the experimental results with a theoretical model based on Maxwell-Garnett mixing formula.

  3. Attenuation correction for small animal PET tomographs

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Patrick L [David Geffen School of Medicine at UCLA, Crump Institute for Molecular Imaging, University of California, 700 Westwood Plaza, Los Angeles, CA 90095 (United States); Rannou, Fernando R [Departamento de Ingenieria Informatica, Universidad de Santiago de Chile (USACH), Av. Ecuador 3659, Santiago (Chile); Chatziioannou, Arion F [David Geffen School of Medicine at UCLA, Crump Institute for Molecular Imaging, University of California, 700 Westwood Plaza, Los Angeles, CA 90095 (United States)

    2005-04-21

    Attenuation correction is one of the important corrections required for quantitative positron emission tomography (PET). This work will compare the quantitative accuracy of attenuation correction using a simple global scale factor with traditional transmission-based methods acquired either with a small animal PET or a small animal x-ray computed tomography (CT) scanner. Two phantoms (one mouse-sized and one rat-sized) and two animal subjects (one mouse and one rat) were scanned in CTI Concorde Microsystem's microPET (registered) Focus{sup TM} for emission and transmission data and in ImTek's MicroCAT{sup TM} II for transmission data. PET emission image values were calibrated against a scintillation well counter. Results indicate that the scale factor method of attenuation correction places the average measured activity concentration about the expected value, without correcting for the cupping artefact from attenuation. Noise analysis in the phantom studies with the PET-based method shows that noise in the transmission data increases the noise in the corrected emission data. The CT-based method was accurate and delivered low-noise images suitable for both PET data correction and PET tracer localization.

  4. Vertical diffuse attenuation coefficient (Kd) based optical ...

    Indian Academy of Sciences (India)

    The optical classification of the different water types provides vital input for studies related to primary productivity, water clarity and determination of euphotic depth. Image data of the IRS- P3 MOS-B, for Path 90 of 27th February, 1998 was used for deriving vertical diffuse attenuation Coeffcient () and an optical ...

  5. Switching Control for Adaptive Disturbance Attenuation

    NARCIS (Netherlands)

    Battistelli, Giorgio; Mari, Daniele; Selvi, Daniela; Tesi, Alberto; Tesi, Pietro

    The problem of adaptive disturbance attenuation is addressed in this paper using a switching control approach. A finite family of stabilizing controllers is pre-designed, with the assumption that, for any possible operating condition, at least one controller is able to achieve a prescribed level of

  6. Vertical diffuse attenuation coefficient (Kd) based optical ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    The optical classification of the different water types provides vital input for studies related to primary productivity, water clarity and determination of euphotic depth. Image data of the IRS-. P3 MOS-B, for Path 90 of 27th February, 1998 was used for deriving vertical diffuse attenuation coefficient (Kd) and an optical ...

  7. A constrained supersymmetric left-right model

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, Martin [AHEP Group, Instituto de Física Corpuscular - C.S.I.C./Universitat de València, Edificio de Institutos de Paterna, Apartado 22085, E-46071 València (Spain); Krauss, Manuel E. [Bethe Center for Theoretical Physics & Physikalisches Institut der Universität Bonn, Nussallee 12, 53115 Bonn (Germany); Institut für Theoretische Physik und Astronomie, Universität Würzburg,Emil-Hilb-Weg 22, 97074 Wuerzburg (Germany); Opferkuch, Toby [Bethe Center for Theoretical Physics & Physikalisches Institut der Universität Bonn, Nussallee 12, 53115 Bonn (Germany); Porod, Werner [Institut für Theoretische Physik und Astronomie, Universität Würzburg,Emil-Hilb-Weg 22, 97074 Wuerzburg (Germany); Staub, Florian [Theory Division, CERN,1211 Geneva 23 (Switzerland)

    2016-03-02

    We present a supersymmetric left-right model which predicts gauge coupling unification close to the string scale and extra vector bosons at the TeV scale. The subtleties in constructing a model which is in agreement with the measured quark masses and mixing for such a low left-right breaking scale are discussed. It is shown that in the constrained version of this model radiative breaking of the gauge symmetries is possible and a SM-like Higgs is obtained. Additional CP-even scalars of a similar mass or even much lighter are possible. The expected mass hierarchies for the supersymmetric states differ clearly from those of the constrained MSSM. In particular, the lightest down-type squark, which is a mixture of the sbottom and extra vector-like states, is always lighter than the stop. We also comment on the model’s capability to explain current anomalies observed at the LHC.

  8. Robotic left hepatectomy with revision of hepaticojejunostomy

    Directory of Open Access Journals (Sweden)

    Kuo-Hsin Chen

    2014-04-01

    Full Text Available Laparoscopic hepatectomy and hepaticojejunostomy remain a surgical challenge despite the recent advances in minimally invasive surgery. A robotic surgical system has been developed to overcome the inherent limitations of the traditional laparoscopic approach. However, techniques of robotic hepatectomy have not been well described, and a description of robotic major hepatectomy with bilioenteric anastomosis can be found only in two previous reports. Here, we report a 33-year-old man with a history of choledochocyst resection. The patient experienced repeat cholangitis with left hepatolithiasis during follow-up. Robotic left hepatectomy and revision of hepaticojejunostomy were performed smoothly. The patient recovered uneventfully and remained symptoms-free at a follow-up of 20 months. The robotic approach is beneficial in the fine dissection of the hepatic hilum and revision of hepaticojejunostomy in this particular patient.

  9. Minimal Left-Right Symmetric Dark Matter.

    Science.gov (United States)

    Heeck, Julian; Patra, Sudhanwa

    2015-09-18

    We show that left-right symmetric models can easily accommodate stable TeV-scale dark matter particles without the need for an ad hoc stabilizing symmetry. The stability of a newly introduced multiplet either arises accidentally as in the minimal dark matter framework or comes courtesy of the remaining unbroken Z_{2} subgroup of B-L. Only one new parameter is introduced: the mass of the new multiplet. As minimal examples, we study left-right fermion triplets and quintuplets and show that they can form viable two-component dark matter. This approach is, in particular, valid for SU(2)×SU(2)×U(1) models that explain the recent diboson excess at ATLAS in terms of a new charged gauge boson of mass 2 TeV.

  10. Off-pump anastomosis of the left internal mammary artery to the left anterior descending coronary artery through a left inferior J-hemisternotomy

    DEFF Research Database (Denmark)

    Modrau, Ivy; Nielsen, Per Hostrup; Nielsen, Dorthe Viemose

    2016-01-01

    of left internal mammary artery grafting to the left anterior descending coronary artery, off-pump through a left inferior J-hemisternotomy (JOPCAB). This approach is straightforward, safe, effective, and replicable in virtually all patients. JOPCAB requires no patient selection or other prerequisite than...

  11. Pretreatment with fish oil attenuates heart ischaemia consequences in rats.

    Science.gov (United States)

    Lescano de Souza Junior, Alcione; Mancini Filho, Jorge; Pavan Torres, Rosângela; Irigoyen, Maria Cláudia; Curi, Rui

    2017-11-01

    What is the central question of this study? We investigated whether pretreatment with fish oil could prevent the major consequences of ischaemic injury to the heart. What is the main finding and its importance? Fish oil pretreatment attenuated the consequences of ischaemic injury as indicated by the small infarction area and the preservation of systolic function and coronary blood flow. These findings support the use of fish oil in order to reduce the impact of heart ischaemia. ω-3 Polyunsaturated fatty acid (ω-3 PUFA)-rich fish oil supplementation has protective effects on heart ischaemic injury. Left ventricular (LV) ischaemia was induced in rats by permanent ligation of the left descending coronary artery. Saline, fish oil or soybean oil was administered daily by gavage [3 g (kg body weight)-1 ] for 20 days before inducing ischaemia. Outcomes were assessed 24 h after left descending coronary artery ligation. Pretreatment with fish oil decreased the ω-6/ω-3 fatty acid ratio in the LV. A reduction in infarct size and in the intensity of ventricular systolic dysfunction was found in the fish oil group compared with the saline or soybean oil groups through echocardiographic evaluation. Before infarction, LV glycogen concentrations were decreased in the fish oil group compared with the saline group. Soybean oil pretreatment led to a further increase in the LV levels of CINC-2/αβ, IL-1β and TNF-α induced by the heart infarction. In heart-infarcted rats, fish oil pretreatment decreased creatine kinase and caspase-3 activities; prevented the decrease in the coronary blood flow; increased LV contents of ATP and lactate; increased the mRNA levels of iNOS, eNOS, HIF1α, GLUT1, VEGF-α and p53 in the LV as measured by RT-PCR; and did not change LV pro-inflammatory cytokine concentrations compared with the control group. Fish oil protected the heart from ischaemia, as indicated by the decrease in the heart infarction area and systolic dysfunction associated with

  12. Novel Toll-like receptor-4 deficiency attenuates trastuzumab (Herceptin induced cardiac injury in mice

    Directory of Open Access Journals (Sweden)

    Yousif Nasser

    2011-10-01

    Full Text Available Abstract Background Cardiac inflammation and generation of oxidative stress are known to contribute to trastuzumab (herceptin induced cardiac toxicity. Toll-like receptors (TLRs are a part of the innate immune system and are involved in cardiac stress reactions. Since TLR4 might play a relevant role in cardiac inflammatory signaling, we investigated whether or not TLR4 is involved in trastuzumab induced cardiotoxicity. Methods Seven days after a single injection of herceptin (2 mg/kg; i.p., left ventricular pressure volume loops were measured in HeN compotent (TLR4+/+ and HeJ mutant (TLR4-/- treated with trastuzumab and control mice. Immunofluorescent staining for monocyte infiltration and analyses of plasma by (ELISAs for different chemokines including: MCP-1and tumor necrosis factor-α (TNF-α, Western immunoblotting assay for ICAM-1, and used troponin I for cardiac injury marker. Results Trastuzumab injection resulted in an impairment of left ventricular function in TLR-4 competent (HeN, in contrast TLR4-/- trastuzumab mice showed improved left ventricular function EF%, CO; p -/-; p -/-, marked reduction of myocardial troponin-I levels in TLR4-deficient mice. Data are presented as means ± SE; n = 8 in each group p Conclusions Treatment with trastuzumab induces an inflammatory response that contributes to myocardial tissue TLR4 mediates chemokine expression (TNF-α, MCP-1and ICAM-1, so in experimental animals TLR4 deficiency improves left ventricular function and attenuates pathophysiological key mechanisms in trastuzumab induced cardiomyopathy.

  13. Total agenesis of the left pericardium

    Directory of Open Access Journals (Sweden)

    J. Glauco Lobo Fº

    1999-09-01

    Full Text Available This is the report of a 46-year-old patient with the preoperative diagnosis of an atrial septal defect (ASD of the ostium secudum type. After sternectomy, partial agenesis of the left pericardium was diagnosed. It is our opinion that, if the radiographic picture is suggestive of this entity, a clinical search for cardiopulmonary anomalies should be performed, because the majority of these associated anomalies can and should be surgically corrected.

  14. Hypoplastic left heart syndrome: a review

    OpenAIRE

    Gobergs, Roberts; Salputra, Elza; Lubaua, Ing?na

    2016-01-01

    Background. Hypoplastic left heart syndrome (HLHS) is an etiologically multifactorial congenital heart disease affecting one in 5,000 newborns. Thirty years ago there were no treatment options for this pathology and the natural course of the disease led to death, usually within the first weeks of life. Recently surgical palliative techniques have been developed allowing for a five-year survival in more than half the cases. Materials and methods. We reviewed literature available on HLHS, speci...

  15. Hypoplastic left heart syndrome: current perspectives

    OpenAIRE

    Greenleaf, Christopher E.; Urencio, J. Miguel; Salazar, Jorge D.; Dodge-Khatami, Ali

    2016-01-01

    Since the first successful intervention for hypoplastic left heart syndrome (HLHS) was undertaken by Norwood in 1983, there have been many advancements in the pre-, intra-, and postoperative care of these children for a diagnosis that just 25 years ago was almost certainly a fatal one. This paper aims to describe the most recent trends and perspectives on the treatment of HLHS. In particular, we will discuss the five current options for HLHS, including Norwood stage I as the beginning to 3-st...

  16. Advances in Left Atrial Appendage Occlusion Strategies

    OpenAIRE

    Arash Aryana; Sheldon M. Singh; Shephal K. Doshi; Andr� d�Avila

    2013-01-01

    Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide and associated with an elevated risk of thromboembolic stroke and systemic embolization. The evidence suggests that ~90% of thrombi in patients with non-valvular AF are localized to the left atrial appendage (LAA). Therefore, it seems reasonable to consider LAA exclusion in selected patients with AF for stroke prevention. LAA exclusion can be achieved through a variety of surgical and percutaneous techniques. Surgical me...

  17. Retrotracheal aberrant left brachiocephalic vein: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Yigit, Adalet E.; Haliloglu, Mithat; Karcaaltincaba, Musturay; Ariyurek, Macit O. [Hacettepe University Faculty of Medicine, Department of Radiology, Ankara (Turkey)

    2008-03-15

    We present a child with double aberrant left brachiocephalic vein (ALBCV) that was an incidental finding on CT. The anterior and thin branch was above the aortic arch and behind the truncus brachiocephalicus and drained into the superior vena cava (SVC). The posterior and thick branch of the ALBCV coursed posterior to the trachea and oesophagus and joined with the azygos vein before draining into the SVC. To our knowledge, retrotracheal ALBCV has not been previously described. (orig.)

  18. Coronary Anomalies: Left Main Coronary Artery Aneurysm

    OpenAIRE

    Varda, Rajsekhar; Chitimilla, Santosh Kumar; Lalani, Aslam

    2012-01-01

    Coronary artery aneurysm is one of the rarest anomalies that we see in our medical practice and they are mostly associated with obstructive lesions due to atherosclerotic changes. Management of these aneurysm patients (conservative or surgical repair) usually depends on obstructive lesions and associated symptoms. We are presenting a case of left main aneurysm measuring around 1 4 × 2 8  mm with other obstructive leisons. It was treated with surgical repair in view of obstructive lesions and ...

  19. Coronary Anomalies: Left Main Coronary Artery Aneurysm

    Directory of Open Access Journals (Sweden)

    Rajsekhar Varda

    2012-01-01

    Full Text Available Coronary artery aneurysm is one of the rarest anomalies that we see in our medical practice and they are mostly associated with obstructive lesions due to atherosclerotic changes. Management of these aneurysm patients (conservative or surgical repair usually depends on obstructive lesions and associated symptoms. We are presenting a case of left main aneurysm measuring around 14×28 mm with other obstructive leisons. It was treated with surgical repair in view of obstructive lesions and symptoms.

  20. Giant and thrombosed left ventricular aneurysm

    OpenAIRE

    de Agustin, Jose Alberto; de Diego, Jose Juan Gomez; Marcos-Alberca, Pedro; Rodrigo, Jose Luis; Almeria, Carlos; Mahia, Patricia; Luaces, Maria; Garcia-Fernandez, Miguel Angel; Macaya, Carlos; de Isla, Leopoldo Perez

    2015-01-01

    Left ventricular aneurysms are a frequent complication of acute extensive myocardial infarction and are most commonly located at the ventricular apex. A timely diagnosis is vital due to the serious complications that can occur, including heart failure, thromboembolism, or tachyarrhythmias. We report the case of a 78-year-old male with history of previous anterior myocardial infarction and currently under evaluation by chronic heart failure. Transthoracic echocardiogram revealed a huge thrombo...

  1. Vernacular Revival and Ideology - What's Left?

    OpenAIRE

    Guillery, P.

    2017-01-01

    This essay derives from a lecture first given at a Vernacular Architecture Group conference on vernacular revivals in 2015, reprised to generally younger audiences at the Bartlett School of Architecture and the University of Westminster. Its retrospection about vernacular architecture, anonymity, revival and left-wing ideologies was prompted primarily by a bemused awareness of recent advances in self-building. It seemed timely to try to get at how and why certain ideas retain traction. Then, ...

  2. Anomalous Origin of Left Circumflex Artery

    Science.gov (United States)

    Çitaku, Hajdin; Kamberi, Lulzim; Gorani, Daut; Koçinaj, Dardan; Krasniqi, Xhevdet

    2015-01-01

    Introduction: The coronary anatomic variation of the left circumflex artery (LCx) is considered as the most common anatomic variation with a separate ostium from the right sinus, and very unusual variation as a proximal branch of right coronary artery (RCA). Case report: We report two cases, the first case is a 64-year-old man with chest pain and with history of hypertension, obesity, dyslipidemia and current smoker, and the second case is a 67-year-old who presented to the emergency department with chest pain and with a past medical history of arterial hypertension and type 2 diabetes mellitus. In the coronarography of the first case is detected an ectopic left circumflex coronary artery from the right coronary sinus with stenotic changes in RCA and LCx. The second case in the coronary angiography revealed an ectopic left circumflex coronary artery from the proximal part of the right coronary artery with stenotic changes in LAD, RCA and LCx. Based on guidelines for revascularization our patients successfully underwent treatment procedures. We present two cases that because of the atherosclerotic coronary artery disease leads to the need of coronarography find out the presence of coronary artery anomalies. Conclusion: During the coronarography we should think about coronary artery anomaly or missing artery knowing that type of these anomalies, considering that may be a contributing factor in the development of the atherosclerosis determines the method of the treatment. PMID:26843740

  3. [Takotsubo syndrome. Transient left ventricular dyskinesia].

    Science.gov (United States)

    Pérez Pérez, F M; Sánchez Salado, J

    2014-03-01

    The Takotsubo syndrome, also called transient apical dyskinesia syndrome, was first described in Japan in the 1990s. It is a rare entity found in almost 1% of all patients with suspicion of acute coronary syndrome. It usually affects postmenopausal women with a few cardiovascular risk factors. It is characterized by angina-type chest pain, electrocardiographic changes, elevation of the enzymes of myocardial injury, absence of coronary obstruction on angiography, and a characteristic left ventricular anteroapical dyskinesia, which returns to normal within a few days. Severe emotional stress is the most common trigger for this syndrome. The aetiopathogenesis of this syndrome remains to be defined. This syndrome has been considered a clinical condition since 2001, when a series of 88 cases was published. It is a disease with a partially known mechanism, characterised by the morphology adopted by the left ventricle secondary to hypokinesis or dyskinesia of the apical segments, and hypercontractility of basal segments. Unlike acute coronary syndrome, patients with left ventricle dysfunction do not have atherothrombotic disease in the coronary arteries. In addition, the alterations described are reversible. Some clinical diagnostic criteria have been proposed, although they are still controversial, as well as in the complementary examinations required for diagnosis. Copyright © 2012 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.

  4. Pulmonary hypertension due to left heart disease.

    Science.gov (United States)

    Berthelot, Emmanuelle; Bailly, Minh Tam; Hatimi, Safwane El; Robard, Ingrid; Rezgui, Hatem; Bouchachi, Amir; Montani, David; Sitbon, Olivier; Chemla, Denis; Assayag, Patrick

    Pulmonary hypertension due to left heart disease, also known as group 2 pulmonary hypertension according to the European Society of Cardiology/European Respiratory Society classification, is the most common cause of pulmonary hypertension. In patients with left heart disease, the development of pulmonary hypertension favours right heart dysfunction, which has a major impact on disease severity and outcome. Over the past few years, this condition has been considered more frequently. However, epidemiological studies of group 2 pulmonary hypertension are less exhaustive than studies of other causes of pulmonary hypertension. In group 2 patients, pulmonary hypertension may be caused by an isolated increase in left-sided filling pressures or by a combination of this condition with increased pulmonary vascular resistance, with an abnormally high pressure gradient between arteries and pulmonary veins. A better understanding of the conditions underlying pulmonary hypertension is of key importance to establish a comprehensive diagnosis, leading to an adapted treatment to reduce heart failure morbidity and mortality. In this review, epidemiology, mechanisms and diagnostic approaches are reviewed; then, treatment options and future approaches are considered. Copyright © 2017. Published by Elsevier Masson SAS.

  5. Vergisson 4: a left-handed Neandertal.

    Science.gov (United States)

    Condemi, Silvana; Monge, Janet; Quertelet, Sylvain; Frayer, David W; Combier, Jean

    2017-01-01

    Handedness is an important marker for lateralization of humans in the modern and fossil record. For the most part, Neandertals and their ancestors are strongly right-handed. We describe a single tooth from a Neandertal level at Vergisson 4 (Vg 4-83). This left upper central incisor shows all the features typical of Neandertal incisors. It also exhibits a predominance of left-handed striations. Striations on the incisor's labial surface were mapped at 20x magnification using Photoshop. Angulations of the striations were determined from their deviation from the maximum mesio-distal line and were analyzed using NIH's freeware, Image J. Of the 60 labial surface striations, Vg 4-83 shows a strong predominance of left-handed striations (46; 76.7%), which are statistically significantly different (p Neandertal adds to our understanding about handedness variation in this fossil hominin. Given the high frequency of right-handed Neandertals, the 90: 10 modern ratio is still preserved in this group. © 2016 Wiley Periodicals, Inc.

  6. Left-Deviating Prism Adaptation in Left Neglect Patient: Reflexions on a Negative Result

    Directory of Open Access Journals (Sweden)

    Jacques Luauté

    2012-01-01

    Full Text Available Adaptation to right-deviating prisms is a promising intervention for the rehabilitation of patients with left spatial neglect. In order to test the lateral specificity of prism adaptation on left neglect, the present study evaluated the effect of left-deviating prism on straight-ahead pointing movements and on several classical neuropsychological tests in a group of five right brain-damaged patients with left spatial neglect. A group of healthy subjects was also included for comparison purposes. After a single session of exposing simple manual pointing to left-deviating prisms, contrary to healthy controls, none of the patients showed a reliable change of the straight-ahead pointing movement in the dark. No significant modification of attentional paper-and-pencil tasks was either observed immediately or 2 hours after prism adaptation. These results suggest that the therapeutic effect of prism adaptation on left spatial neglect relies on a specific lateralized mechanism. Evidence for a directional effect for prism adaptation both in terms of the side of the visuomanual adaptation and therefore possibly in terms of the side of brain affected by the stimulation is discussed.

  7. Electrocardiographic markers of left ventricular systolic dysfunction in patients with left bundle branch block.

    Science.gov (United States)

    Deniz, Ali; Özmen, Çağlar; Aktaş, Halil; Berk, İlayda Gül; Deveci, Onur Sinan; Çağlıyan, Çağlar Emre; Eker Akıllı, Rabia; Kanadaşı, Mehmet; Demir, Mesut; Usal, Ayhan

    2016-01-01

    Although some patients with left bundle branch block (LBBB) have structural heart diseases, some patients with LBBB have "normal hearts". The electrocardiography (ECG) criteria of LBBB in reduced left ventricular ejection fraction (LVEF) have not been defined completely. The main purpose of this study was to differentiate patients with reduced LVEF from patients with normal left ventricular systolic function simply by analysing 12-lead ECG. Subjects admitted to our hospital with LBBB in their ECG were included in the study. The patients were categorised according to their left ventricular systolic function as group 1 (LVEF ≥ 50%) and group 2 (LVEF bundle branch, and concordance/discordance of T waves in leads V5, V6, or D1 were recorded. The ECG findings of the two groups were compared. One hundred consecutive patients with LBBB were included in the study (male/female: 56/44, age: 66 ± 15 years). In the whole group, there were 35 patients with normal left ventricular systolic function (LVEF ≥ 50%), and 65 patients had LVEF below 50%. 80% of male patients with LBBB and 45% of female patients with LBBB had their LVEF below 50% (p bundle branch was more frequent in group 2 (29% in group 1 vs. 52% in group 2, p = 0.03). Male gender, QRS duration greater than 140 ms, discordant LBBB, and residual conduction in the left bundle branch seem to be markers of reduced LVEF in patients with LBBB.

  8. Science in the Making: Right Hand, Left Hand. III: Estimating historical rates of left-handedness.

    Science.gov (United States)

    McManus, I C; Moore, James; Freegard, Matthew; Rawles, Richard

    2010-01-01

    The BBC television programme Right Hand, Left Hand, broadcast in August 1953, used a postal questionnaire to ask viewers about their handedness. Respondents were born between 1864 and 1948, and in principle therefore the study provides information on rates of left-handedness in those born in the nineteenth century, a group for which few data are otherwise available. A total of 6,549 responses were received, with an overall rate of left-handedness of 15.2%, which is substantially above that expected for a cohort born in the nineteenth and early twentieth centuries. Left-handers are likely to respond preferentially to surveys about handedness, and the extent of over-response can be estimated in modern control data obtained from a handedness website, from the 1953 BBC data, and from Crichton-Browne's 1907 survey, in which there was also a response bias. Response bias appears to have been growing, being relatively greater in the most modern studies. In the 1953 data there is also evidence that left-handers were more common among later rather than early responders, suggesting that left-handers may have been specifically recruited into the study, perhaps by other left-handers who had responded earlier. In the present study the estimated rate of bias was used to correct the nineteenth-century BBC data, which was then combined with other available data as a mixture of two constrained Weibull functions, to obtain an overall estimate of handedness rates in the nineteenth century. The best estimates are that left-handedness was at its nadir of about 3% for those born between about 1880 and 1900. Extrapolating backwards, the rate of left-handedness in the eighteenth century was probably about 10%, with the decline beginning in about 1780, and reaching around 7% in about 1830, although inevitably there are many uncertainties in those estimates. What does seem indisputable is that rates of left-handedness fell during most of the nineteenth century, only subsequently to rise in

  9. Clinical psychomotor skills among left and right handed medical students: are the left-handed medical students left out?

    Science.gov (United States)

    Alnassar, Sami; Alrashoudi, Aljoharah Nasser; Alaqeel, Mody; Alotaibi, Hala; Alkahel, Alanoud; Hajjar, Waseem; Al-Shaikh, Ghadeer; Alsaif, Abdulaziz; Haque, Shafiul; Meo, Sultan Ayoub

    2016-03-22

    There is a growing perception that the left handed (LH) medical students are facing difficulties while performing the clinical tasks that involve psychomotor skill, although the evidence is very limited and diverse. The present study aimed to evaluate the clinical psychomotor skills among Right-handed (RH) and left-handed (LH) medical students. For this study, 54 (27 left handed and 27 right handed) first year medical students were selected. They were trained for different clinical psychomotor skills including suturing, laparoscopy, intravenous cannulation and urinary catheterization under the supervision of certified instructors. All students were evaluated for psychomotor skills by different instructors. The comparative performance of the students was measured by using a global rating scale, each selected criteria was allotted 5-points score with the total score of 25. There were no significant differences in the performance of psychomotor skills among LH and RH medical students. The global rating score obtained by medical students in suturing techniques was: LH 15.89 ± 2.88, RH 16.15 ± 2.75 (p = 0.737), cannulation techniques LH 20.44 ± 2.81, RH 20.70 ± 2.56 (p = 0.725), urinary catheterization LH 4.33 ± 0.96 RH 4.11 ± 1.05 (p = 0.421). For laparoscopic skills total peg transfer time was shorter among LH medical students compared to RH medical students (LH 129.85 ± 80.87 s vs RH 135.52 ± 104.81 s) (p = 0.825). However, both RH and LH students completed their procedure within the stipulated time. Among LH and RH medical students no significant difference was observed in performing the common surgical psychomotor skills. Surgical skills for LH or RH might not be a result of innate dexterity but rather the academic environment in which they are trained and assessed. Early laterality-related mentoring in medical schools as well as during the clinical residency might reduce the inconveniences faced by the left

  10. Left Ventricular Strain Rate is Reduced during Voluntary Apnea in Healthy Humans.

    Science.gov (United States)

    Smith, Joshua R; Sutterfield, Shelbi L; Baumfalk, Dryden R; Didier, Kaylin D; Hammer, Shane M; Caldwell, Jacob Troy; Ade, Carl J

    2017-09-14

    During an apneic event, sympathetic nerve activity increases resulting in subsequent increases in left ventricular afterload and myocardial work. It is unknown how cardiac mechanics are acutely impacted by the increased myocardial work during an apneic event. 10 healthy individuals (23 ± 3 yrs) performed multiple voluntary end-expiratory apnea (VEEA) maneuvers exposed to room air, while a subset (n=7) completed multiple VEEA exposed to hyperoxic air (100% FiO2). Beat-by-beat blood pressure, heart rate and stroke volume were measured continuously. Effective arterial elastance (EA) was calculated as an index of cardiac afterload and myocardial work calculated as the rate pressure product (RPP). Tissue Doppler echocardiography was used to measure left ventricular (LV) tissue velocities, and deformation via strain, and strain rate (SR). Systolic blood pressure (Δ18 ± 13 mmHg, p0.18) EA or RPP and attenuated the systolic blood pressure response compared to room air. Myocardial velocities and LV strain rate response to VEEA were unchanged (p=0.30) with hyperoxia. Consistent with our hypotheses, VEEA-induced increases in EA and myocardial work impact left ventricular mechanics, which may depend, in part, on stimulation of peripheral chemoreceptors. Copyright © 2017, Journal of Applied Physiology.

  11. Evaluation of satellite derived spectral diffuse attenuation coefficients

    Digital Repository Service at National Institute of Oceanography (India)

    Suresh, T.; Talaulikar, M.; Desa, E.; Mascarenhas, A.A.M.Q.; Matondkar, S.G.P.

    Spectral diffuse attenuation K sub(d)(lambda) is an important apparent optical property that provide information about the attenuation of the spectral downwelling solar irradiance with depth in water. The spectral K sub(d)(lambda) at lambda = 412...

  12. Attenuation of seismic waves in Central Egypt

    Directory of Open Access Journals (Sweden)

    Mamdouh Abbas Morsy

    2013-06-01

    Full Text Available Attenuation of seismic waves in central Egypt had never been studied before. The results of the research on the seismic attenuation are based upon the information collected by the seismological network from 1998 to 2011. 855 earthquakes were selected from the Egyptian seismological catalog, with their epicenter distances between 15 and 150 km, their magnitudes ranging from 2 and 4.1 and focal depths reaching up to 30 km. The first systematic study of attenuation derived from the P-, S- and coda wave in the frequency range 1–24 Hz is presented. In the interpretation of the results both single and multiple scattering in a half space are considered. The single scattering model proposed by Sato (1977 was used. Two methods, the coda (Qc and the Multiple Lapse Time Window (MLTW method are used. The aim of this study is to validate these interpretations in the region and to try to identify the effects of attenuation due to intrinsic (Qi and scattering attenuation (Qsc. The mean Qc value calculated was Qc = (39 ± 1f1.0±0.009. The average Qc at 1.5 Hz is (53 ± 6 and Qc = (900 ± 195 at 24 Hz with Qo ranging between 23 and 107, where η ranging between 0.9 and 1.3. The quality factor (Q was estimated from spectra of P- and S-waves by applying a spectral ratio technique. The results show variations in Qp and QS as a function of frequency, according to the power law Q = 56η1.1. The seismic albedo is 0.7 at all stations and it mean that the earthquake activity is due to tectonic origin. The attenuation and frequency dependency for different paths and the correlation of the results with the geotectonic of the region are presented. The Qc values were calculated and correlated with the geology and tectonics of the area. The relatively low Qo and the high frequency dependency agree with the values of a region characterized by a low tectonic activity and vise versa.

  13. Left ventricular heart failure and pulmonary hypertension†

    Science.gov (United States)

    Rosenkranz, Stephan; Gibbs, J. Simon R.; Wachter, Rolf; De Marco, Teresa; Vonk-Noordegraaf, Anton; Vachiéry, Jean-Luc

    2016-01-01

    In patients with left ventricular heart failure (HF), the development of pulmonary hypertension (PH) and right ventricular (RV) dysfunction are frequent and have important impact on disease progression, morbidity, and mortality, and therefore warrant clinical attention. Pulmonary hypertension related to left heart disease (LHD) by far represents the most common form of PH, accounting for 65–80% of cases. The proper distinction between pulmonary arterial hypertension and PH-LHD may be challenging, yet it has direct therapeutic consequences. Despite recent advances in the pathophysiological understanding and clinical assessment, and adjustments in the haemodynamic definitions and classification of PH-LHD, the haemodynamic interrelations in combined post- and pre-capillary PH are complex, definitions and prognostic significance of haemodynamic variables characterizing the degree of pre-capillary PH in LHD remain suboptimal, and there are currently no evidence-based recommendations for the management of PH-LHD. Here, we highlight the prevalence and significance of PH and RV dysfunction in patients with both HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF), and provide insights into the complex pathophysiology of cardiopulmonary interaction in LHD, which may lead to the evolution from a ‘left ventricular phenotype’ to a ‘right ventricular phenotype’ across the natural history of HF. Furthermore, we propose to better define the individual phenotype of PH by integrating the clinical context, non-invasive assessment, and invasive haemodynamic variables in a structured diagnostic work-up. Finally, we challenge current definitions and diagnostic short falls, and discuss gaps in evidence, therapeutic options and the necessity for future developments in this context. PMID:26508169

  14. Left ventricular heart failure and pulmonary hypertension.

    Science.gov (United States)

    Rosenkranz, Stephan; Gibbs, J Simon R; Wachter, Rolf; De Marco, Teresa; Vonk-Noordegraaf, Anton; Vachiéry, Jean-Luc

    2016-03-21

    In patients with left ventricular heart failure (HF), the development of pulmonary hypertension (PH) and right ventricular (RV) dysfunction are frequent and have important impact on disease progression, morbidity, and mortality, and therefore warrant clinical attention. Pulmonary hypertension related to left heart disease (LHD) by far represents the most common form of PH, accounting for 65-80% of cases. The proper distinction between pulmonary arterial hypertension and PH-LHD may be challenging, yet it has direct therapeutic consequences. Despite recent advances in the pathophysiological understanding and clinical assessment, and adjustments in the haemodynamic definitions and classification of PH-LHD, the haemodynamic interrelations in combined post- and pre-capillary PH are complex, definitions and prognostic significance of haemodynamic variables characterizing the degree of pre-capillary PH in LHD remain suboptimal, and there are currently no evidence-based recommendations for the management of PH-LHD. Here, we highlight the prevalence and significance of PH and RV dysfunction in patients with both HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF), and provide insights into the complex pathophysiology of cardiopulmonary interaction in LHD, which may lead to the evolution from a 'left ventricular phenotype' to a 'right ventricular phenotype' across the natural history of HF. Furthermore, we propose to better define the individual phenotype of PH by integrating the clinical context, non-invasive assessment, and invasive haemodynamic variables in a structured diagnostic work-up. Finally, we challenge current definitions and diagnostic short falls, and discuss gaps in evidence, therapeutic options and the necessity for future developments in this context. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.

  15. Intravascular ultrasound assessment of distal left main bifurcation disease: the importance of the polygon of confluence of the left main, left anterior descending, and left circumflex arteries.

    Science.gov (United States)

    Kang, Soo-Jin; Mintz, Gary S; Oh, Jun-Hyok; Park, Duk-Woo; Lee, Seung-Whan; Kim, Young-Hak; Lee, Cheol Whan; Park, Seong-Wook; Park, Seung-Jung

    2013-11-01

    The polygon of confluence (POC) represents the zone of confluence of the distal left main (LM), ostial left anterior descending (LAD), and ostial left circumflex (LCX) arteries. We used intravascular ultrasound (IVUS) to assess the POC pre and post-drug-eluting stent implantation for unprotected distal LM disease. Four segments within 82 LM bifurcation lesions were defined by longitudinal IVUS reconstruction: (1) ostial LAD, (2) POC, and (3) distal LM (DLM)--from LAD-pullback, and (4) ostial LCX from LCX-pullback. Preprocedural minimum lumen area (MLA) and poststenting minimum stent area (MSA) within the LM were mainly located within the POC (51 and 71%). On ROC analysis, a cut-off of the MLA within the POC of 6.1 mm(2) predicted significant LCX carinal stenosis (85% sensitivity, 52% specificity, AUC = 0.7, 95% CI = 0.57-0.78, P < 0.01). Poststenting MSA within the distal LM proximal to the carina (to include DLM and POC) positively correlated with the preprocedural MLA within the POC (r = 0.283, P = 0.02); it was significantly smaller in 48 lesions with a pre-PCI MLA within the POC < 6.1 mm(2) versus 25 lesions with a pre-PCI MLA ≥6.1 mm(2) (7.5 ± 2.1 mm(2) vs. 8.6 ± 2.0 mm(2), P = 0.04). Independent predictors for poststenting LCX carinal MLA also included preprocedural MLA within the POC (β = 0.240, 95% CI = 0.004-0.353, P = 0.04). The MLA within the POC was a good surrogate reflecting the overall severity of LM bifurcation disease including ostial LCX stenosis pre-PCI and the ability to expand a stent within the distal LM as well as final ostial LCX lumen area post-PCI. Copyright © 2011 Wiley Periodicals, Inc.

  16. Patients with left bundle branch block and left axis deviation show a specific left ventricular asynchrony pattern: Implications for left ventricular lead placement during CRT implantation.

    Science.gov (United States)

    Sciarra, Luigi; Golia, Paolo; Palamà, Zefferino; Scarà, Antonio; De Ruvo, Ermenegildo; Borrelli, Alessio; Martino, Anna Maria; Minati, Monia; Fagagnini, Alessandro; Tota, Claudia; De Luca, Lucia; Grieco, Domenico; Delise, Pietro; Calò, Leonardo

    2017-10-21

    Left bundle branch block (LBBB) and left axis deviation (LAD) patients may have poor response to resynchronization therapy (CRT). We sought to assess if LBBB and LAD patients show a specific pattern of mechanical asynchrony. CRT candidates with non-ischemic cardiomyopathy and LBBB were categorized as having normal QRS axis (within -30° and +90°) or LAD (within -30° and -90°). Patients underwent tissue Doppler imaging (TDI) to measure time interval between onset of QRS complex and peak systolic velocity in ejection period (Q-peak) at basal segments of septal, inferior, lateral and anterior walls, as expression of local timing of mechanical activation. Thirty patients (mean age 70.6years; 19 males) were included. Mean left ventricular ejection fraction was 0.28±0.06. Mean QRS duration was 172.5±13.9ms. Fifteen patients showed LBBB with LAD (QRS duration 173±14; EF 0.27±0.06). The other 15 patients had LBBB with a normal QRS axis (QRS duration 172±14; EF 0.29±0.05). Among patients with LAD, Q-peak interval was significantly longer at the anterior wall in comparison to each other walls (septal 201±46ms, inferior 242±58ms, lateral 267±45ms, anterior 302±50ms; p<0.0001). Conversely, in patients without LAD Q-peak interval was longer at lateral wall, when compared to each other (septal 228±65ms, inferior 250±64ms, lateral 328±98ms, anterior 291±86ms; p<0.0001). Patients with heart failure, presenting LBBB and LAD, show a specific pattern of ventricular asynchrony, with latest activation at anterior wall. This finding could affect target vessel selection during CRT procedures in these patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. On the excess attenuation of sound in the atmosphere

    Science.gov (United States)

    Deloach, R.

    1975-01-01

    The attenuation suffered by an acoustic plane wave propagating from an elevated source to the ground, in excess of absorption losses, was studied. Reported discrepancies between attenuation measurements made in the field and theories which only account for absorption losses are discussed. It was concluded that the scattering of sound by turbulence results in a nonnegligible contribution to the total attenuation.

  18. Measurement of atomic number and mass attenuation coefficient in ...

    Indian Academy of Sciences (India)

    The linear attenuation coefficient (), mass attenuation coefficient (/ρ), total atomic cross-section (tot), total electronic cross-section (ele) and the effective atomic number (eff) were calculated for pure magnesium ferrite (MgFe2O4). The values of -ray mass attenuation coefficient were obtained using a NaI energy ...

  19. Comparison of Attenuation of petroleum hydrocarbons in surface ...

    African Journals Online (AJOL)

    Comparison of Attenuation of petroleum hydrocarbons in surface and subsurface soils amended with biostimulants. ... Results suggest that natural attenuation can be a viable remediation strategy in soils with neutral to alkaline pH and that low pH of amendment material used could reduce TPH attenuation. Keywords: ...

  20. Preventive effect of yuzu and hesperidin on left ventricular remodeling and dysfunction in rat permanent left anterior descending coronary artery occlusion model.

    Science.gov (United States)

    Yu, Hye Yon; Ahn, Ji Hun; Park, Se Won; Jung, Yi-Sook

    2015-01-01

    Left ventricular (LV) remodeling, which includes ventricular dilatation and increased interstitial fibrosis after myocardial infarction (MI), is the critical process underlying the progression to heart failure. Therefore, a novel approach for preventing LV remodeling after MI is highly desirable. Yuzu is a citrus plant originating in East Asia, and has a number of cardioprotective properties such as hesperidin. However, no study has proved whether yuzu can prevent LV remodeling. The aim of this study was to determine the effects of yuzu on heart failure (HF) and its potential impact on the LV remodeling process after MI. Our in vivo study using the permanent left anterior descending coronary artery (LAD) occlusion model demonstrate that one week pre-treatment with yuzu or its major metabolite hesperidin before LAD occlusion significantly attenuated cardiac dysfunction, myocyte apoptosis and inflammation. Not only yuzu but also hesperidin inhibited caspase-3 activity, myeloperoxidase expression, α-smooth muscle actin expression, and matrix metalloproteinase-2 activity in a permanent LAD occlusion rat model. To our knowledge, our findings provide the first evidence that yuzu and hesperidin prevent MI-induced ventricular dysfunction and structural remodeling of myocardium.

  1. Preventive Effect of Yuzu and Hesperidin on Left Ventricular Remodeling and Dysfunction in Rat Permanent Left Anterior Descending Coronary Artery Occlusion Model

    Science.gov (United States)

    Yu, Hye Yon; Ahn, Ji Hun; Park, Se Won; Jung, Yi-Sook

    2015-01-01

    Left ventricular (LV) remodeling, which includes ventricular dilatation and increased interstitial fibrosis after myocardial infarction (MI), is the critical process underlying the progression to heart failure. Therefore, a novel approach for preventing LV remodeling after MI is highly desirable. Yuzu is a citrus plant originating in East Asia, and has a number of cardioprotective properties such as hesperidin. However, no study has proved whether yuzu can prevent LV remodeling. The aim of this study was to determine the effects of yuzu on heart failure (HF) and its potential impact on the LV remodeling process after MI. Our in vivo study using the permanent left anterior descending coronary artery (LAD) occlusion model demonstrate that one week pre-treatment with yuzu or its major metabolite hesperidin before LAD occlusion significantly attenuated cardiac dysfunction, myocyte apoptosis and inflammation. Not only yuzu but also hesperidin inhibited caspase-3 activity, myeloperoxidase expression, α-smooth muscle actin expression, and matrix metalloproteinase-2 activity in a permanent LAD occlusion rat model. To our knowledge, our findings provide the first evidence that yuzu and hesperidin prevent MI-induced ventricular dysfunction and structural remodeling of myocardium. PMID:25559243

  2. Blueberry Anthocyanins-Enriched Extracts Attenuate Cyclophosphamide-Induced Cardiac Injury.

    Directory of Open Access Journals (Sweden)

    Yunen Liu

    Full Text Available We sought to explore the effect of blueberry anthocyanins-enriched extracts (BAE on cyclophosphamide (CTX-induced cardiac injury. The rats were divided randomly into five groups including normal control, CTX 100 mg/kg, BAE 80mg/kg, CTX+BAE 20mg/kg and CTX+BAE 80mg/kg groups. The rats in the three BAE-treated groups were administered BAE for four weeks. Seven days after BAE administration, rats in CTX group and two BAE-treated groups were intraperitoneally injected with a single dose of 100 mg/kg CTX. Cardiac injury was assessed using physiological parameters, Echo, morphological staining, real-time PCR and western blot. In addition, cardiotoxicity indices, inflammatory cytokines expression and oxidative stress markers were also detected. Four weeks 20mg/kg and 80mg/kg dose of BAE treatment following CTX exposure attenuated mean arterial blood pressure, heart rate and activities of heart enzymes, improved cardiac dysfunction, left ventricular hypertrophy and fibrosis. Importantly, BAE also attenuated CTX-induced LV leukocyte infiltration and inflammatory cytokines expression, ameliorated oxidative stress as well as cardiomyocyte apoptosis. In conclusion, BAE attenuated the CTX-induced cardiac injury and the protective mechanisms were related closely to the anti-inflammatory, antioxidant and anti-inflammatory characteristics of BAE.

  3. Blueberry Anthocyanins-Enriched Extracts Attenuate Cyclophosphamide-Induced Cardiac Injury.

    Science.gov (United States)

    Liu, Yunen; Tan, Dehong; Shi, Lin; Liu, Xinwei; Zhang, Yubiao; Tong, Changci; Song, Dequn; Hou, Mingxiao

    2015-01-01

    We sought to explore the effect of blueberry anthocyanins-enriched extracts (BAE) on cyclophosphamide (CTX)-induced cardiac injury. The rats were divided randomly into five groups including normal control, CTX 100 mg/kg, BAE 80mg/kg, CTX+BAE 20mg/kg and CTX+BAE 80mg/kg groups. The rats in the three BAE-treated groups were administered BAE for four weeks. Seven days after BAE administration, rats in CTX group and two BAE-treated groups were intraperitoneally injected with a single dose of 100 mg/kg CTX. Cardiac injury was assessed using physiological parameters, Echo, morphological staining, real-time PCR and western blot. In addition, cardiotoxicity indices, inflammatory cytokines expression and oxidative stress markers were also detected. Four weeks 20mg/kg and 80mg/kg dose of BAE treatment following CTX exposure attenuated mean arterial blood pressure, heart rate and activities of heart enzymes, improved cardiac dysfunction, left ventricular hypertrophy and fibrosis. Importantly, BAE also attenuated CTX-induced LV leukocyte infiltration and inflammatory cytokines expression, ameliorated oxidative stress as well as cardiomyocyte apoptosis. In conclusion, BAE attenuated the CTX-induced cardiac injury and the protective mechanisms were related closely to the anti-inflammatory, antioxidant and anti-inflammatory characteristics of BAE.

  4. A new landing impact attenuation seat in manned spacecraft biologically-inspired by felids

    Directory of Open Access Journals (Sweden)

    Yu Hui

    2015-04-01

    Full Text Available When manned spacecraft comes back to the earth, it relies on the impact attenuation seat to protect astronauts from injuries during landing phase. Hence, the seat needs to transfer impact load, as small as possible, to the crew. However, there is little room left for traditional seat to improve further. Herein, a new seat system biologically-inspired by felids’ landing is proposed. Firstly, a series of experiments was carried out on cats and tigers, in which they were trained to jump down voluntarily from different heights. Based on the ground reaction forces combined with kinematics, the experiment indicated that felids’ landing after self-initial jump was a multi-step impact attenuation process and the new seat was inspired by this. Then the construction and work process of new seat were redesigned to realize the multi-step impact attenuation. The dynamic response of traditional and new seat is analyzed under the identical conditions and the results show that the new concept seat can significantly weaken the occupant overload in two directions compared with that of traditional seat. As a consequence, the risk of injury evaluated for spinal and head is also lowered, meaning a higher level of protection which is especially beneficial to the debilitated astronaut.

  5. Hypoplastic left heart syndrome: current perspectives

    Science.gov (United States)

    Greenleaf, Christopher E.; Urencio, J. Miguel; Salazar, Jorge D.

    2016-01-01

    Since the first successful intervention for hypoplastic left heart syndrome (HLHS) was undertaken by Norwood in 1983, there have been many advancements in the pre-, intra-, and postoperative care of these children for a diagnosis that just 25 years ago was almost certainly a fatal one. This paper aims to describe the most recent trends and perspectives on the treatment of HLHS. In particular, we will discuss the five current options for HLHS, including Norwood stage I as the beginning to 3-stage palliation, transplant, true hybrid, hybrid-bridge-to-Norwood, and compassionate care. PMID:27709095

  6. Hypoplastic left heart syndrome – Unresolved Issues

    Directory of Open Access Journals (Sweden)

    Raoul Roman Arnold

    2014-11-01

    Full Text Available Hypoplastic left heart syndrome (HLHS is one of the most challenging congenital heart defects. At present it is expected that - at best - 70% of newborns with HLHA will reach adulthood. This review addresses the problems of right ventricular failure and insufficient growth of pulmonary vasculature in these patients. In order to further improve long-term prognosis translational research to control right ventricular function and growth of pulmonary arteries and progress in chronic circulatory support are clearly needed to provide a further improvement for adults with HLHS.

  7. Topologically left invariant means on semigroup algebras

    Indian Academy of Sciences (India)

    -compact in M(S)∗∗ . We define the semiflow (M0(S), ) by putting ρ(µ,F) = µF for µ ∈ M(S) and F ∈. M(S)∗∗ . By hypothesis, there exists M ∈ that is fixed under the action of M0(S), that is µM = M for every µ ∈ M0(S). It follows that M is a topologically left invariant mean on M(S)∗ . This completes our proof. 2. A right action of ...

  8. Doubling left syntactic positions in Danish

    DEFF Research Database (Denmark)

    Jørgensen, Henrik

    2016-01-01

    This paper deals with the doubling of left syntactic positions in Danish. Such doublings consist of a referential element: a NP or a clause, and an anaphoric element, an unstressed personal pronoun or an unstressed resumptive adverb. In main clauses, the CP-spec position may double in this way, w...... in the analysis of a broadcasted public speech (sect. 5). In earlier versions of Danish, as shown in sect. 4, the construction is both more frequent in writing and also seems almost obligatory....

  9. Mycobacterium chimaera left ventricular assist device infections.

    Science.gov (United States)

    Balsam, Leora B; Louie, Eddie; Hill, Fred; Levine, Jamie; Phillips, Michael S

    2017-06-01

    A global outbreak of invasive Mycobacterium chimaera infections after cardiac surgery has recently been linked to bioaerosols from contaminated heater-cooler units. The majority of cases have occurred after valvular surgery or aortic graft surgery and nearly half have resulted in death. To date, infections in patients with left ventricular assist devices (LVADs) have not been characterized in the literature. We report two cases of device-associated M. chimaera infection in patients with continuous-flow LVADs and describe challenges related to diagnosis and management in this population. © 2017 Wiley Periodicals, Inc.

  10. Multimodal agnosia after unilateral left hemisphere lesion.

    Science.gov (United States)

    Feinberg, T E; Rothi, L J; Heilman, K M

    1986-06-01

    Agnosia is an abnormality of recognition that is not explained by sensory or cognitive disorders. We studied a patient who had combined visual-tactile agnosia without prosopagnosia after a left hemisphere infarct. Although he copied figures presented visually and he performed intramodal or crossmodal visual-tactile matches, he could not indicate recognition by either sight or touch. The lesion involved areas of the occipital and temporal lobes that may be important for human performance of tasks that require construction and application of meaning to percepts presented both visually and tactually.

  11. Backus and Wyllie Averages for Seismic Attenuation

    Science.gov (United States)

    Qadrouh, Ayman N.; Carcione, José M.; Ba, Jing; Gei, Davide; Salim, Ahmed M.

    2017-09-01

    Backus and Wyllie equations are used to obtain average seismic velocities at zero and infinite frequencies, respectively. Here, these equations are generalized to obtain averages of the seismic quality factor (inversely proportional to attenuation). The results indicate that the Wyllie velocity is higher than the corresponding Backus quantity, as expected, since the ray velocity is a high-frequency limit. On the other hand, the Wyllie quality factor is higher than the Backus one, following the velocity trend, i.e., the higher the velocity (the stiffer the medium), the higher the attenuation. Since the quality factor can be related to properties such as porosity, permeability, and fluid viscosity, these averages can be useful for evaluating reservoir properties.

  12. Analysis of Signal Attenuation in UHF Band

    Directory of Open Access Journals (Sweden)

    Libor Michalek

    2015-01-01

    Full Text Available This paper deals with signal attenuation in ultra-high-frequency bands caused by rain. We focus mainly on the effect of the rain on the radio waves propagation in the frequency band 2.1 GHz. Two exact approaches for investigating this dependency are used. In the first approach, we use the fitting probability density function for determination Rician distribution K-factor. In the second approach, we want to find more concrete rain-rate dependency with using linear regression. The results achieved in our long-term investigation clearly indicate that the strong impact of rain itself is a minor. So-called secondary rain impacts such as scattering of reflections from wet surfaces cause the main attenuation contribution.

  13. Tricolor attenuation model for shadow detection.

    Science.gov (United States)

    Tian, Jiandong; Sun, Jing; Tang, Yandong

    2009-10-01

    Shadows, the common phenomena in most outdoor scenes, bring many problems in image processing and computer vision. In this paper, we present a novel method focusing on extracting shadows from a single outdoor image. The proposed tricolor attenuation model (TAM) that describe the attenuation relationship between shadow and its nonshadow background is derived based on image formation theory. The parameters of the TAM are fixed by using the spectral power distribution (SPD) of daylight and skylight, which are estimated according to Planck's blackbody irradiance law. Based on the TAM, a multistep shadow detection algorithm is proposed to extract shadows. Compared with previous methods, the algorithm can be applied to process single images gotten in real complex scenes without prior knowledge. The experimental results validate the performance of the model.

  14. The Attenuation of Swell Waves by Rain

    Science.gov (United States)

    Cavaleri, Luigi; Bertotti, Luciana

    2017-10-01

    Within the progressive improvement in wave modeling we focus on the attenuation of swell waves by rain. Till now ignored, the process is shown to be relevant, especially for the correct estimate of swell. Following the practical impossibility of devoted field experiments, we exploit the global model results over a period of more than four years to extract the tiny signal associated to the attenuation by rain. A direct comparison of the ratio model by altimeter significant wave heights versus the encountered rain amount hints to a marked related dependence. A proper quantification of the related physical effect requires a multiple step procedure that we describe in detail. We check the reliability of the results, and we provide the related source function ready for implementation in operational wave models.

  15. Implicit temporal expectation attenuates auditory attentional blink.

    Directory of Open Access Journals (Sweden)

    Dawei Shen

    Full Text Available Attentional blink (AB describes a phenomenon whereby correct identification of a first target impairs the processing of a second target (i.e., probe nearby in time. Evidence suggests that explicit attention orienting in the time domain can attenuate the AB. Here, we used scalp-recorded, event-related potentials to examine whether auditory AB is also sensitive to implicit temporal attention orienting. Expectations were set up implicitly by varying the probability (i.e., 80% or 20% that the probe would occur at the +2 or +8 position following target presentation. Participants showed a significant AB, which was reduced with the increased probe probability at the +2 position. The probe probability effect was paralleled by an increase in P3b amplitude elicited by the probe. The results suggest that implicit temporal attention orienting can facilitate short-term consolidation of the probe and attenuate auditory AB.

  16. Mars Pathfinder Airbag Impact Attenuation System

    Science.gov (United States)

    Waye, Donald; Cole, J. Kenneth; Rivellini, Tommaso P.

    1995-01-01

    The Mars Pathfinder spacecraft, scheduled for launch in December 1996, is designed to validate a low cost Entry, Descent, and Landing system and to perform scientific surface operations. The Jet Propulsion Laboratory and Sandia National Laboratories teamed to design, fabricate, test and validate a prototype 0.38 scale model of an airbag impact attenuation system. A computer code was developed to predict the performance of the airbag system. A test program in Sandia's High Altitude Chamber was performed to validate the code and demonstrate the feasibility of the airbag concept and design. In addition, freefall tests were performed at representative velocities to demonstrate the structural integrity of the airbag system design. The feasibility program demonstrated that the airbag impact attenuation design will protect the lander upon impact with the Martian surface.

  17. LCLS XTOD Attenuator System System Concept Report

    Energy Technology Data Exchange (ETDEWEB)

    Kishiyama, K; Roeben, M; Trent, J; Ryutov, D; Shen, S

    2006-04-12

    The attenuator system for the Linac Coherent Light Source (LCLS) X-ray Transport, Optics and Diagnostics (XTOD) system has been configured and analyzed by the Lawrence Livermore National Laboratory's New Technologies Engineering Division (NTED) as requested by the SLAC/LCLS program. The system layout, performance analyses and selection of the vacuum components are presented in this System Conceptual Review (SCR) report. Also included are the plans for prototype, procurement, mechanical integration, and the cost estimates.

  18. Two-dimensional dynamic fluid bowtie attenuators.

    Science.gov (United States)

    Hermus, James R; Szczykutowicz, Timothy P

    2016-01-01

    Fluence field modulated (FFM) CT allows for improvements in image quality and dose reduction. To date, only one-dimensional modulators have been proposed, as the extension to two-dimensional (2-D) modulation is difficult with solid-metal attenuation-based fluence field modulated designs. This work proposes to use liquid and gas to attenuate the x-ray beam, as unlike solids, these materials can be arranged allowing for 2-D fluence modulation. The thickness of liquid and the pressure for a given path length of gas were determined that provided the same attenuation as 30 cm of soft tissue at 80, 100, 120, and 140 kV. Liquid iodine, zinc chloride, cerium chloride, erbium oxide, iron oxide, and gadolinium chloride were studied. Gaseous xenon, uranium hexafluoride, tungsten hexafluoride, and nickel tetracarbonyl were also studied. Additionally, we performed a proof-of-concept experiment using a 96 cell array in which the liquid thickness in each cell was adjusted manually. Liquid thickness varied as a function of kV and chemical composition, with erbium oxide allowing for the smallest thickness. For the gases, tungsten hexaflouride required the smallest pressure to compensate for 30 cm of soft tissue. The 96 cell iodine attenuator allowed for a reduction in both dynamic range to the detector and scatter-to-primary ratio. For both liquids and gases, when k-edges were located within the diagnostic energy range used for imaging, the mean beam energy exhibited the smallest change with compensation amount. The thickness of liquids and the gas pressure seem logistically implementable within the space constraints of C-arm-based cone beam CT (CBCT) and diagnostic CT systems. The gas pressures also seem logistically implementable within the space and tube loading constraints of CBCT and diagnostic CT systems.

  19. Study of Sound Attenuation in Sediments.

    Science.gov (United States)

    1984-12-01

    experimental difficulties. In the ocean, the sediment is inaccesible , the propagation path is inhomoveneonis, and information on lavering usually has to... STANDARDS 1963 A RFPRODUCED AT GOVERNMENT EXPENSE Ln ~STUDY OF SOUND ATTENUATION IN SEDIMENTS Stephen R. Addison and Henry F. Bass PARGUM Report 84-03*A 4*I...measured porosity decreased to 0.39. The standard deviation in all these porosity measurements was 0.01. A porosity of 0.40 is used in all subsequent

  20. What Is an Attenuated Psychotic Symptom?

    DEFF Research Database (Denmark)

    Fusar-Poli, Paolo; Raballo, Andrea; Parnas, Josef

    2016-01-01

    Attenuated psychotic symptoms (APS) are the key criteria to identify the individuals at enhanced risk of developing psychotic disorders. Competing clinicians-rated or self-rated psychometric instruments can also be used to detect APS, which makes it difficult to interpret their actual clinical...... significance. This article summarizes the empirical differences between the clinicians-rated and self-rated interviews and explores the impact of the context (referral pathways, settings, and assessment procedures) on the clinical significance of the APS....

  1. Renal sympathetic denervation attenuates hypertension and vascular remodeling in renovascular hypertensive rats.

    Science.gov (United States)

    Li, Peng; Huang, Pei-Pei; Yang, Yun; Liu, Chi; Lu, Yan; Wang, Fang; Sun, Wei; Kong, Xiang-Qing

    2017-01-01

    Li P, Huang P, Yang Y, Liu C, Lu Y, Wang F, Sun W, Kong X. Renal sympathetic denervation attenuates hypertension and vascular remodeling in renovascular hypertensive rats. J Appl Physiol 122: 121-129, 2017. First published October 14, 2016; doi:10.1152/japplphysiol.01019.2015-Sympathetic activity is enhanced in patients with essential or secondary hypertension, as well as in various hypertensive animal models. Therapeutic targeting of sympathetic activation is considered an effective antihypertensive strategy. We hypothesized that renal sympathetic denervation (RSD) attenuates hypertension and improves vascular remodeling and renal disease in the 2-kidney, 1-clip (2K1C) rat model. Rats underwent 2K1C modeling or sham surgery; then rats underwent RSD or sham surgery 4 wk later, thus resulting in four groups (normotensive-sham, normotensive-RSD, 2K1C-sham, and 2K1C-RSD). Norepinephrine was measured by ELISA. Echocardiography was used to assess heart function. Fibrosis and apoptosis were assessed by Masson and TUNEL staining. Changes in mean arterial blood pressure in response to hexamethonium and plasma norepinephrine levels were used to evaluate basal sympathetic nerve activity. The 2K1C modeling success rate was 86.8%. RSD reversed the elevated systolic blood pressure induced by 2K1C, but had no effect on body weight. Compared with rats in the 2K1C-sham group, rats in the 2K1C-RSD group showed lower left ventricular mass/body weight ratio, interventricular septal thickness in diastole, left ventricular end-systolic diameter, and left ventricular posterior wall thickness in systole, whereas fractional shortening and ejection fraction were higher. Right kidney apoptosis and left kidney hypertrophy were not changed by RSD. Arterial fibrosis was lower in animals in the 2K1C-RSD group compared with those in the 2K1C-sham group. RSD reduced plasma norepinephrine and basal sympathetic activity in rats in the 2K1C-RSD group compared with rats in the 2K1C-sham group. These

  2. Attenuation compensation for optical coherence tomography imaging

    Science.gov (United States)

    Chang, Shoude; Flueraru, Costel; Mao, Youxin; Sherif, Sherif

    2009-12-01

    Optical coherence tomography (OCT) is a noninvasive technique that provides micrometer-scale imaging of tissue. As most biological tissues are considered turbid, it causes attenuation of the OCT signal and limits the depth penetration. Although a few algorithms had been developed to compensate the attenuation, almost all of them need to extract the scattering parameters before doing the compensation procedure. Because the real biological samples are anisotropic and multilayer-like structure, it is not time-efficient to model and solve these scattering parameters. This paper introduces a new method to compensate the OCT signal attenuation in depth. By analyzing the input signal, a compensation function is adaptively derived for each A-scan line, which can be used effectively to compensate the energy loss in the large sections and enhance the details in the deep, dark-like areas. Three bio-samples, a piece of onion, a Poecilia Wingei fish and a piece of rabbit abdominal aorta, were used to test our method. OCT images obtained by a swept-source OCT system were processed by the proposed method. Results show the visualization of structures in OCT images has been evidently improved, especially in deep region.

  3. Broadband Vibration Attenuation Using Hybrid Periodic Rods

    Directory of Open Access Journals (Sweden)

    S. Asiri

    2008-12-01

    Full Text Available This paper presents both theoretically and experimentally a new kind of a broadband vibration isolator. It is a table-like system formed by four parallel hybrid periodic rods connected between two plates. The rods consist of an assembly of periodic cells, each cell being composed of a short rod and piezoelectric inserts. By actively controlling the piezoelectric elements, it is shown that the periodic rods can efficiently attenuate the propagation of vibration from the upper plate to the lower one within critical frequency bands and consequently minimize the effects of transmission of undesirable vibration and sound radiation. In such a system, longitudinal waves can propagate from the vibration source in the upper plate to the lower one along the rods only within specific frequency bands called the "Pass Bands" and wave propagation is efficiently attenuated within other frequency bands called the "Stop Bands". The spectral width of these bands can be tuned according to the nature of the external excitation. The theory governing the operation of this class of vibration isolator is presented and their tunable filtering characteristics are demonstrated experimentally as functions of their design parameters. This concept can be employed in many applications to control the wave propagation and the force transmission of longitudinal vibrations both in the spectral and spatial domains in an attempt to stop/attenuate the propagation of undesirable disturbances.

  4. Novel Intriguing Strategies Attenuating to Sarcopenia

    Directory of Open Access Journals (Sweden)

    Kunihiro Sakuma

    2012-01-01

    Full Text Available Sarcopenia, the age-related loss of skeletal muscle mass, is characterized by a deterioration of muscle quantity and quality leading to a gradual slowing of movement, a decline in strength and power, increased risk of fall-related injury, and, often, frailty. Since sarcopenia is largely attributed to various molecular mediators affecting fiber size, mitochondrial homeostasis, and apoptosis, the mechanisms responsible for these deleterious changes present numerous therapeutic targets for drug discovery. Resistance training combined with amino acid-containing supplements is often utilized to prevent age-related muscle wasting and weakness. In this review, we summarize more recent therapeutic strategies (myostatin or proteasome inhibition, supplementation with eicosapentaenoic acid (EPA or ursolic acid, etc. for counteracting sarcopenia. Myostatin inhibitor is the most advanced research with a Phase I/II trial in muscular dystrophy but does not try the possibility for attenuating sarcopenia. EPA and ursolic acid seem to be effective as therapeutic agents, because they attenuate the degenerative symptoms of muscular dystrophy and cachexic muscle. The activation of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α in skeletal muscle by exercise and/or unknown supplementation would be an intriguing approach to attenuating sarcopenia. In contrast, muscle loss with age may not be influenced positively by treatment with a proteasome inhibitor or antioxidant.

  5. Heart Failure with Transient Left Bundle Branch Block in the Setting of Left Coronary Fistula

    Directory of Open Access Journals (Sweden)

    Stephen P. Juraschek

    2011-01-01

    Full Text Available Coronary arterial fistulas are rare communications between vessels or chambers of the heart. Although cardiac symptoms associated with fistulas are well described, fistulas are seldom considered in the differential diagnosis of acute myocardial ischemia. We describe the case of a 64-year-old man who presented with left shoulder pain, signs of heart failure, and a new left bundle branch block (LBBB. Cardiac catheterization revealed a small left anterior descending (LAD-to-pulmonary artery (PA fistula. Diuresis led to subjective improvement of the patient's symptoms and within several days the LBBB resolved. We hypothesize that the coronary fistula in this patient contributed to transient ischemia of the LAD territory through a coronary steal mechanism. We elected to observe rather than repair the fistula, as his symptoms and ECG changes resolved with treatment of his heart failure.

  6. challenges left-handed students face in kenyan girls' secondary

    African Journals Online (AJOL)

    IICBA01

    CHALLENGES LEFT-HANDED STUDENTS FACE IN. KENYAN GIRLS' SECONDARY SCHOOL. SCIENCE LABORATORIES. Benerdeta Mwikali Malusi. Mount Kenya University, Kenya. Email: faithemm@gmail.com. ABSTRACT. Previous research on left-handedness has mainly taken place in developed countries. This.

  7. Incidental retroaortic left innominate vein in adult patient

    Directory of Open Access Journals (Sweden)

    Alexandre Semionov, MD, PhD

    2017-09-01

    Full Text Available Retro-aortic left innominate vein is a rare vascular abnormality, usually associated with congenital heart disease. Here we report a case of isolated retro-aortic left innominate vein in an adult female.

  8. Rare occurrence of the left maxillary horizontal third molar impaction ...

    African Journals Online (AJOL)

    Rare occurrence of the left maxillary horizontal third molar impaction, the right maxillary third molar vertical impaction and the left mandibular third molar vertical impaction with inferior alveolar nerve proximity in a 30 year old female: a case report.

  9. Behavioral evidence for left-hemisphere specialization of motor planning

    NARCIS (Netherlands)

    Janssen, L.; Meulenbroek, R.G.J.; Steenbergen, B.

    2011-01-01

    Recent studies suggest that the left hemisphere is dominant for the planning of motor actions. This left-hemisphere specialization hypothesis was proposed in various lines of research, including patient studies, motor imagery studies, and studies involving neurophysiological techniques. However,

  10. Shared Frailty Model for Left-Truncated Multivariate Survival Data

    DEFF Research Database (Denmark)

    Jensen, Henrik; Brookmeyer, Ron; Aaby, Peter

    multivariate survival data, left truncation, multiplicative hazard model, shared gamma frailty, conditional model, piecewise exponential model, childhood survival......multivariate survival data, left truncation, multiplicative hazard model, shared gamma frailty, conditional model, piecewise exponential model, childhood survival...

  11. Reversal of left ventricular hypertrophy by propranolol in ...

    African Journals Online (AJOL)

    Background: Hypertension contributes significantly to the development of left ventricular hypertrophy. Left ventricular hypertrophy is associated with increased incidence of sudden cardiac death. Recognition and management of hypertension is, therefore, imperative. Objective: To establish whether propranolol can reverse ...

  12. Left atrial catheter ablation and ischemic stroke.

    Science.gov (United States)

    Haeusler, Karl Georg; Kirchhof, Paulus; Endres, Matthias

    2012-01-01

    Left atrial catheter ablation (LACA) has become an established therapy to abolish drug-refractory symptomatic paroxysmal and persistent atrial fibrillation. Restoring sinus rhythm by LACA may help to prevent atrial fibrillation-related strokes, but presently there is no evidence from randomized clinical trials to support this notion. This review summarizes the current knowledge and uncertainties regarding LACA and procedure-related ischemic stroke. In fact, most patients who undergo LACA have a rather low annual stroke risk even when left untreated, whereas LACA imposes a risk of procedure-related stroke of ≈0.5% to 1%. In addition, LACA may cause cerebral microemboli, resulting in ischemic lesions. These cerebral lesions, detectable by high-resolution MRI, could contribute to neuropsychological deficits and cognitive dysfunction. Furthermore, recurrent atrial fibrillaton episodes can be detected up to years after LACA and might cause ischemic strokes, especially in those patients in whom therapeutic anticoagulation was discontinued. Further prospective multicenter trials are needed to identify procedure-dependent risk factors for stroke and to optimize postprocedural anticoagulation management.

  13. Endometrial Adenocarcinoma with Concomitant Left Atrial Myxoma

    Directory of Open Access Journals (Sweden)

    Lisa N. Abaid

    2009-08-01

    Full Text Available Background: Atrial myxomas are the most common primary heart tumors and predominantly considered to be benign lesions. Case Study: We report a case involving a 77-year-old woman who presented with a pelvic mass. She was found to have a primary endometrial cancer and primary lung cancer with concomitant metastatic adrenal gland and mesenteric lesions. Her prior medical history also included an untreated 4.0 × 2.0-cm left atrial myxoma which was identified on CT scan during the workup of her pelvic mass. Results: A clinical decision was made to proceed with surgery for the pelvic mass with a subsequent recommendation for left atrial mass resection. Currently, the patient is scheduled to begin chemotherapy for primary lung cancer. Conclusion: The reported incidence of uterine cancer and a concurrent atrial myxoma is very rare. Consequently, the manner and timing in which treatment should be provided is imprecise. In the present case, the risk for cardiac complications was high, but given the presence of a partial bowel obstruction and the need to diagnose the primary site of her metastatic malignancy, the decision was made to proceed with exploratory abdominal surgery.

  14. Coronary artery to left ventricle fistula

    Directory of Open Access Journals (Sweden)

    Kumar Vivek

    2005-11-01

    Full Text Available Abstract Background Coronary cameral fistulas are an uncommon entity, the etiology of which may be congenital or traumatic. They involve abnormal termination of a coronary artery, usually the right coronary, into a cardiac chamber, usually the right ventricle. Case Presentation We describe a case of female patient with severe aortic stenosis and interventricular septal hypertrophy that underwent bioprosthetic aortic valve replacement with concomitant septal myectomy. On subsequent follow-up an abnormal flow traversing the septum into the left ventricle was identified and Doppler interrogation demonstrated a continuous flow, with a predominantly diastolic component, consistent with coronary arterial flow. Conclusion The literature on coronary cameral fistulas is reviewed and the etiology of the diagnostic findings discussed. In our patient, a coronary artery to left ventricle fistula was the most likely explanation secondary to trauma to the septal perforator artery during myectomy. Since the patient was asymptomatic at the time of diagnosis no intervention was recommended and has done well on follow-up.

  15. Left coronary artery stenosis causing left ventricular dysfunction in two children with supravalvular aortic stenosis.

    Science.gov (United States)

    Yildiz, Okan; Altin, Firat H; Kaya, Mehmet; Ozyılmaz, Isa; Guzeltas, Alper; Erek, Ersin

    2015-04-01

    Congenital supravalvar aortic stenosis (SVAS) is an arteriopathy associated with Williams-Beuren syndrome (WBS) and other isolated elastin gene deletions. Cardiovascular manifestations associated with WBS are characterized by obstructive arterial lesions such as SVAS and pulmonary artery stenosis in addition to bicuspid aortic valve and mitral valve prolapse. However, coronary artery ostial stenosis may be associated with SVAS, and it increases the risk of sudden death and may complicate surgical management. In this report, we present our experience with two patients having SVAS and left coronary artery ostial stenosis with associated left ventricular dysfunction. © The Author(s) 2014.

  16. Left Ventricular Thrombus Formation After Repair of Anomalous Left Coronary Artery From the Pulmonary Artery

    Science.gov (United States)

    Freud, Lindsay R.; Koenig, Peter R.; Russell, Hyde M.; Patel, Angira

    2014-01-01

    Although thrombus formation following myocardial infarction in adults is well known, intracardiac thrombosis in children is uncommon. We report the case of a large left ventricular thrombus in an infant with ischemic cardiomyopathy secondary to anomalous origin of the left coronary artery from the pulmonary artery. Given its mobility and protrusion across the aortic valve, the patient underwent urgent thrombus removal through a transaortic approach. There were no embolic or neurologic complications. This case highlights that thrombectomy may be performed safely and successfully in critically ill pediatric patients. PMID:24668990

  17. Anesthetic implications of total anomalous systemic venous connection to left atrium with left isomerism

    Directory of Open Access Journals (Sweden)

    Parimala Prasanna Simha

    2012-01-01

    Full Text Available Total anomalous systemic venous connection (TASVC to the left atrium (LA is a rare congenital anomaly. An 11-year-old girl presented with complaints of palpitations and cyanosis. TASVC with left isomerism and noncompaction of LV was diagnosed after contrast echocardiogram and computed tomography angiogram. The knowledge of anatomy and pathophysiology is essential for the successful management of these cases. Anesthetic concerns in this case were polycythemia, paradoxical embolism and rhythm abnormalities. The patient was successfully operated by rerouting the systemic venous connection to the right atrium.

  18. Myricetin attenuates lung inflammation and provides protection ...

    African Journals Online (AJOL)

    The euthanasia was followed by the collection of lung samples for subsequent experimental analysis. Estimation of 'wet-to-dry' weight ratio. After euthanasia, the extent of pulmonary edema in the experimental groups was assessed by measuring the 'wet-to-dry' weight of the lungs. For this, the left lung was removed and.

  19. Seismic Attenuation Inversion with t* Using tstarTomog.

    Energy Technology Data Exchange (ETDEWEB)

    Preston, Leiph

    2014-09-01

    Seismic attenuation is defined as the loss of the seismic wave amplitude as the wave propagates excluding losses strictly due to geometric spreading. Information gleaned from seismic waves can be utilized to solve for the attenuation properties of the earth. One method of solving for earth attenuation properties is called t*. This report will start by introducing the basic theory behind t* and delve into inverse theory as it pertains to how the algorithm called tstarTomog inverts for attenuation properties using t* observations. This report also describes how to use the tstarTomog package to go from observed data to a 3-D model of attenuation structure in the earth.

  20. Intensity attenuation in the Pannonian Basin

    Science.gov (United States)

    Győri, Erzsébet; Gráczer, Zoltán; Szanyi, Gyöngyvér

    2015-04-01

    Ground motion prediction equations play a key role in seismic hazard assessment. Earthquake hazard has to be expressed in macroseismic intensities in case of seismic risk estimations where a direct relation to the damage associated with ground shaking is needed. It can be also necessary for shake map generation where the map is used for prompt notification to the public, disaster management officers and insurance companies. Although only few instrumental strong motion data are recorded in the Pannonian Basin, there are numerous historical reports of past earthquakes since the 1763 Komárom earthquake. Knowing the intensity attenuation and comparing them with relations of other areas - where instrumental strong motion data also exist - can help us to choose from the existing instrumental ground motion prediction equations. The aim of this work is to determine an intensity attenuation formula for the inner part of the Pannonian Basin, which can be further used to find an adaptable ground motion prediction equation for the area. The crust below the Pannonian Basin is thin and warm and it is overlain by thick sediments. Thus the attenuation of seismic waves here is different from the attenuation in the Alp-Carpathian mountain belt. Therefore we have collected intensity data only from the inner part of the Pannonian Basin and defined the boundaries of the studied area by the crust thickness of 30 km (Windhoffer et al., 2005). 90 earthquakes from 1763 until 2014 have sufficient number of macroseismic data. Magnitude of the events varies from 3.0 to 6.6. We have used individual intensity points to eliminate the subjectivity of drawing isoseismals, the number of available intensity data is more than 3000. Careful quality control has been made on the dataset. The different types of magnitudes of the used earthquake catalogue have been converted to local and momentum magnitudes using relations determined for the Pannonian Basin. We applied the attenuation formula by Sorensen

  1. Left-handedness--a handicap for training in surgery?

    Science.gov (United States)

    Tchantchaleishvili, Vakhtang; Myers, Patrick O

    2010-01-01

    Left-handedness was historically considered a disability and a social stigma, and teachers would make efforts to suppress it in their students. Little data are available on the impact of left-handedness on surgical training. This report reviews available data on this subject. We did systematic electronic and manual literature searches using a predetermined strategy independently by 2 investigators, 1 left- and 1 right-handed, to identify reports on surgical training and left-handedness. The review revealed 19 studies on the subject of left-handedness and surgical training. Data were heterogeneous and based mostly on surveys. Left-handedness produced anxiety in residents and their trainers. There was a lack of mentoring on laterality. Surgical instruments, both conventional and laparoscopic, are not adapted to left-handed use and require ambilaterality training from the resident. There is significant pressure to change hand laterality during training. However, left-handedness might present an advantage in operations involving situs inversus or left lower limb operations. Left-handedness is a challenge both for the trainee and the trainer in surgery. Early laterality-related mentoring in medical school and during surgical residency with provision of left-handed instruments might reduce the inconveniences of left-handed surgeons learning. Copyright 2010 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  2. Branching patterns of left coronary artery among North Indians ...

    African Journals Online (AJOL)

    The left coronary artery displays variations in pattern, number and distribution of its branches. These variations influence the manifestation and extent of the coronary artery disease affecting the left main branch. A total of 100 North Indian cadaveric hearts were dissected to observe the main trunk of the left coronary artery.

  3. EEG signal classification to detect left and right command using ...

    African Journals Online (AJOL)

    In this study, the right and left commands explored are based on the actual movement of lifting either left or right hand and the imaginary movement of lifting either left or right hand. For this initial study, EEG signals recorded based on the actual physical movements will be collected as the raw data, as well as the EEG signals ...

  4. Isolated non-compaction of the left ventricle

    African Journals Online (AJOL)

    Electrocardiography showed left ventricular overload, but no signs of ventricular arrhythmias. No neuromuscular abnor mality was found. An echocardiogram showed situs solitus, left aortic arch and atrioventricular-ventriculoarterial concordance; pulmonic veins drained normally to the left atrium and inferior vena cava to.

  5. Left Ventricular Geometry In Nigerians With Type II Diabetes Mellitus ...

    African Journals Online (AJOL)

    Background: Left ventricular hypertrophy is independently associated with increased incidence of cardiovascular disease, cardiovascular and all cause mortality. In a relatively healthy hypertensive adult population, type II diabetes is associated with higher left ventricular mass, concentric left ventricular geometry and lower ...

  6. Determination of the attenuation map in emission tomography

    CERN Document Server

    Zaidi, H

    2002-01-01

    Reliable attenuation correction methods for quantitative emission computed tomography (ECT) require accurate delineation of the body contour and often necessitate knowledge of internal anatomical structure. Two broad classes of methods have been used to calculate the attenuation map referred to as "transmissionless" and transmission-based attenuation correction techniques. While calculated attenuation correction belonging to the first class of methods is appropriate for brain studies, more adequate methods must be performed in clinical applications where the attenuation coefficient distribution is not known a priori, and for areas of inhomogeneous attenuation such as the chest. Measured attenuation correction overcomes this problem and utilizes different approaches to determine this map including transmission scanning, segmented magnetic resonance images or appropriately scaled X-ray CT scans acquired either independently on separate or simultaneously on multimodality imaging systems. Combination of data acqu...

  7. Effect of zinc supplements in the attenuated cardioprotective effect of ischemic preconditioning in hyperlipidemic rat heart.

    Science.gov (United States)

    Kansal, Sunil Kumar; Jyoti, Uma; Sharma, Samridhi; Kaura, Arun; Deshmukh, Rahul; Goyal, Sandeep

    2015-06-01

    Hyperlipidemia is regarded as independent risk factor in the development of ischemic heart disease, and it can increase the myocardial susceptibility to ischemia-/reperfusion (I/R)-induced injury. Hyperlipidemia attenuates the cardioprotective response of ischemic preconditioning (IPC). The present study investigated the effect of zinc supplements in the attenuated cardioprotective effect of ischemic preconditioning in hyperlipidemic rat hearts. Hyperlipidemia was induced in rat by feeding high-fat diet (HFD) for 6 weeks then the serum lipid profile was observed. In experiment, the isolated Langendorff rat heart preparation was subjected to 4 cycles of ischemic preconditioning (IPC), then 30 min of ischemia followed by 120 min of reperfusion. Myocardial infarct size was elaborated morphologically by triphenyltetrazolium chloride (TTC) staining and biochemically by lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) release from coronary effluent and left ventricular collagen content. However, the effect of zinc supplement, i.e., zinc pyrithione (10 μM) perfused during reperfusion for 120 min, significantly abrogated the attenuated cardioprotective effect of ischemic preconditioning in hyperlipidemic rat heart whereas administration of chelator of this zinc ionophore, i.e., N,N,N',N'-tetrakis(2-pyridylmethyl)ethylene diamine (TPEN; 10 μM), perfused during reperfusion 2 min before the perfusion of zinc pyrithione abrogated the cardioprotective effect of zinc supplement during experiment in hyperlipidemic rat heart. Thus, the administration of zinc supplements limits the infarct size, LDH, and CK-MB and enhanced the collagen level which suggests that the attenuated cardioprotective effect of IPC in hyperlipidemic rat is due to zinc loss during reperfusion caused by ischemia/reperfusion.

  8. Efficacy of anticoagulation in resolving left atrial and left atrial appendage thrombi: A transesophageal echocardiographic study

    Science.gov (United States)

    Jaber, W. A.; Prior, D. L.; Thamilarasan, M.; Grimm, R. A.; Thomas, J. D.; Klein, A. L.; Asher, C. R.

    2000-01-01

    BACKGROUND: Transesophageal echocardiography (TEE) is the gold standard for evaluation of the left atrium and the left atrial appendage (LAA) for the presence of thrombi. Anticoagulation is conventionally used for patients with atrial fibrillation to prevent embolization of atrial thrombi. The mechanism of benefit and effectiveness of thrombi resolution with anticoagulation is not well defined. METHODS AND RESULTS: We used a TEE database of 9058 consecutive studies performed between January 1996 and November 1998 to identify all patients with thrombi reported in the left atrium and/or LAA. One hundred seventy-four patients with thrombi in the left atrial cavity (LAC) and LAA were identified (1.9% of transesophageal studies performed). The incidence of LAA thrombi was 6.6 times higher than LAC thrombi (151 vs 23, respectively). Almost all LAC thrombi were visualized on transthoracic echocardiography (90.5%). Mitral valve pathology was associated with LAC location of thrombi (P thrombi. Anticoagulation of 47 +/- 18 days was associated with thrombus resolution in 80.1% of the patients on follow-up TEE. Further anticoagulation resulted in limited additional benefit. CONCLUSIONS: LAC thrombi are rare and are usually associated with mitral valve pathology. Transthoracic echocardiography is effective in identifying these thrombi. LAA thrombi occur predominantly in patients with atrial fibrillation or flutter. Short-term anticoagulation achieves a high rate of resolution of LAA and LAC thrombi but does not obviate the need for follow-up TEE.

  9. Left Hemisphere Regions Are Critical for Language in the Face of Early Left Focal Brain Injury

    Science.gov (United States)

    Beharelle, Anjali Raja; Dick, Anthony Steven; Josse, Goulven; Solodkin, Ana; Huttenlocher, Peter R.; Levine, Susan C.; Small, Steven L.

    2010-01-01

    A predominant theory regarding early stroke and its effect on language development, is that early left hemisphere lesions trigger compensatory processes that allow the right hemisphere to assume dominant language functions, and this is thought to underlie the near normal language development observed after early stroke. To test this theory, we…

  10. New Electromagnetic Absorbers Composed of Left-handed and Right-handed Materials

    Science.gov (United States)

    Fang, Weihai; Xu, Shanjia

    2008-08-01

    New double-layered electromagnetic absorbers are presented in this paper. The new absorbers composed of one lossy left-handed material absorbing layer and one impedance matching layer consisted of lossless right-handed material. It is indicated that the reflection loss of below -20dB can be obtained in the frequency range 7GHz 13GHz. Power attenuation achieving -50dB of narrow frequency band electromagnetic absorbers can also be obtained by modulate permittivity of right-handed material. Furthermore, the thickness of the whole absorbing structure is only 2mm, which is particularly helpful in some practical applications. The presented results are of reference significance for accurate design of the new electromagnetic absorbers and of practical prospects for stealth technology.

  11. Acquired left ventricular-right atrium shunts.

    Science.gov (United States)

    Sinisalo, Juha P; Sreeram, Narayanswami; Jokinen, Eero; Qureshi, Shakeel A

    2011-04-01

    Left ventricular to right atrial (LV-RA) shunt is an unusual type of ventricular septal defect (VSD). This article concentrates on acquired LV-RA shunts, which may be due to complications of cardiac operation, endocarditis, trauma or myocardial infarction. A previous cardiac operation is its most common cause. The diagnosis of LV-RA communication is not easy, and it should be remembered in patients who do not recover normally. Diagnosis can be confirmed with ultrasound or magnetic resonance image (MRI). Surgical correction is usually the treatment of choice, but closing the communication percutaneously should be considered as an option. Copyright © 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

  12. Living donor liver transplantation with hyperreduced left lateral segments.

    Science.gov (United States)

    Kasahara, Mureo; Fukuda, Akinari; Yokoyama, Satoshi; Sato, Shuichi; Tanaka, Hideaki; Kuroda, Tatsuo; Honna, Toshiro

    2008-08-01

    Liver transplantation is now an established technique to treat children with end-stage liver disease. Implantation of left lateral segment grafts (Couidaud's segments II and III) can be a problem in small infants because of a large-for-size graft. Reduced left lateral segmental liver transplantation has been recently introduced for small infants to mitigate the problem of large-for-size graft. Further reduction of the left lateral segment graft increases the possibility of supplying an adequate hyperreduced left lateral segment graft as an alternative surgical technique. We report 3 cases of our experience of transplantation using hyperreduced left lateral segment grafts from living donors.

  13. Hypoplastic left heart syndrome: a review

    Science.gov (United States)

    Gobergs, Roberts; Salputra, Elza; Lubaua, Ingūna

    2016-01-01

    Background. Hypoplastic left heart syndrome (HLHS) is an etiologically multifactorial congenital heart disease affecting one in 5,000 newborns. Thirty years ago there were no treatment options for this pathology and the natural course of the disease led to death, usually within the first weeks of life. Recently surgical palliative techniques have been developed allowing for a five-year survival in more than half the cases. Materials and methods. We reviewed literature available on HLHS, specifically its anatomy, embryology and pathophysiology, and treatment. The Pubmed and ClinicalKey databases were searched using the key words hypoplastic left heart syndrome, foetal aortic valvuloplasty, foetal septoplasty, Norwood procedure, bidirectional Glenn procedure, Fontan procedure, hybrid procedure. The relevant literature was reviewed and included in the article. We reported a case from Children’s Clinical University Hospital, Riga, to illustrate treatment tactics in Latvia. Results. There are three possible directions for therapy in newborns with HLHS: orthotopic heart transplantation, staged surgical palliation and palliative non-surgical treatment or comfort care. Another treatment mode – foetal therapy – has arisen. Staged palliation and full Fontan circulation is a temporary solution, however, the only means for survival until heart transplantation. Fifty to 70% of patients who have gone through all three stages of palliation live to the age of five years. Conclusions. The superior mode of treatment is not yet clear and the management must be based on each individual case, the experience of each clinic, as well as the financial aspects and will of the patient’s parents. PMID:28356795

  14. Estimation of stimulus attenuation in cochlear implants

    CSIR Research Space (South Africa)

    Smit, Jacoba E

    2009-03-01

    Full Text Available B/mm) in scalar fluids, while the Organ of Corti current length constants are 1.00 – 1.15 mm (7.55 – 8.69 dB/mm). Kral et al. (1998) and Hartmann and Klinke (1990) have reported attenuation slopes of around 3 dB/mm (length constant of about 3 mm) for monopolar... in cochlear stimulation. Ann N Y Acad Sci, 1983; 405: 137-45. 30 Blight AR. Computer simulation of action potentials and afterpotentials in mammalian myelinated axons: The case for a lower resistance myelin sheath. Neuroscience, 1985; 15: 13- 31...

  15. The effects of candesartan on left ventricular hypertrophy and function in nonobstructive hypertrophic cardiomyopathy: a pilot, randomized study.

    Science.gov (United States)

    Penicka, Martin; Gregor, Pavel; Kerekes, Roman; Marek, Dan; Curila, Karol; Krupicka, Jiri

    2009-01-01

    Hypertrophic cardiomyopathy is caused by mutations in the genes that encode sarcomeric proteins and is primarily characterized by unexplained left ventricular hypertrophy, impaired cardiac function, reduced exercise tolerance, and a relatively high incidence of sudden cardiac death, especially in the young. The extent of left ventricular hypertrophy is one of the major determinants of disease prognosis. Angiotensin II has trophic effects on the heart and plays an important role in the development of myocardial hypertrophy. Here in a double-blind, placebo-controlled, randomized study, we show that the long-term administration of the angiotensin II type 1 receptor antagonist candesartan in patients with hypertrophic cardiomyopathy was associated with the significant regression of left ventricular hypertrophy, improvement of left ventricular function, and exercise tolerance. The magnitude of the treatment effect was dependent on specific sarcomeric protein gene mutations that had the greatest responses on the carriers of ss-myosin heavy chain and cardiac myosin binding protein C gene mutations. These data indicate that modulating the role of angiotensin II in the development of hypertrophy is specific with respect to both the affected sarcomeric protein gene and the affected codon within that gene. Thus, angiotensin II type 1 receptor blockade has the potential to attenuate myocardial hypertrophy and may, therefore, provide a new treatment option to prevent sudden cardiac death in patients with hypertrophic cardiomyopathy.

  16. Are there right hemisphere contributions to visually-guided movement? Manipulating left hand reaction time advantages in dextrals

    Science.gov (United States)

    Carey, David P.; Otto-de Haart, E. Grace; Buckingham, Gavin; Dijkerman, H. Chris; Hargreaves, Eric L.; Goodale, Melvyn A.

    2015-01-01

    Many studies have argued for distinct but complementary contributions from each hemisphere in the control of movements to visual targets. Investigators have attempted to extend observations from patients with unilateral left- and right-hemisphere damage, to those using neurologically-intact participants, by assuming that each hand has privileged access to the contralateral hemisphere. Previous attempts to illustrate right hemispheric contributions to the control of aiming have focussed on increasing the spatial demands of an aiming task, to attenuate the typical right hand advantages, to try to enhance a left hand reaction time advantage in right-handed participants. These early attempts have not been successful. The present study circumnavigates some of the theoretical and methodological difficulties of some of the earlier experiments, by using three different tasks linked directly to specialized functions of the right hemisphere: bisecting, the gap effect, and visuospatial localization. None of these tasks were effective in reducing the magnitude of left hand reaction time advantages in right handers. Results are discussed in terms of alternatives to right hemispheric functional explanations of the effect, the one-dimensional nature of our target arrays, power and precision given the size of the left hand RT effect, and the utility of examining the proportions of participants who show these effects, rather than exclusive reliance on measures of central tendency and their associated null hypothesis significance tests. PMID:26379572

  17. Vinpocetine attenuates lipid accumulation and atherosclerosis formation

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yujun [Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, 601 Elmwood Ave, Rochester, NY 14642 (United States); Li, Jian-Dong [Center for Inflammation, Immunity and Infection, and Department of Biology, Georgia State University, Atlanta, GA 30303 (United States); Yan, Chen, E-mail: Chen_Yan@urmc.rochester.edu [Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, 601 Elmwood Ave, Rochester, NY 14642 (United States)

    2013-05-10

    Highlights: •Vinpocetine attenuates hyperlipidemia-induced atherosclerosis in a mouse model. •Vinpocetine antagonizes ox-LDL uptake and accumulation in macrophages. •Vinpocetine blocks the induction of ox-LDL receptor LOX-1 in vitro and in vivo. -- Abstract: Atherosclerosis, the major cause of myocardial infarction and stroke, is a chronic arterial disease characterized by lipid deposition and inflammation in the vessel wall. Cholesterol, in low-density lipoprotein (LDL), plays a critical role in the pathogenesis of atherosclerosis. Vinpocetine, a derivative of the alkaloid vincamine, has long been used as a cerebral blood flow enhancer for treating cognitive impairment. Recent study indicated that vinpocetine is a potent anti-inflammatory agent. However, its role in the pathogenesis of atherosclerosis remains unexplored. In the present study, we show that vinpocetine significantly reduced atherosclerotic lesion formation in ApoE knockout mice fed with a high-fat diet. In cultured murine macrophage RAW264.7 cells, vinpocetine markedly attenuated oxidized LDL (ox-LDL) uptake and foam cell formation. Moreover, vinpocetine greatly blocked the induction of ox-LDL receptor 1 (LOX-1) in cultured macrophages as well as in the LOX-1 level in atherosclerotic lesions. Taken together, our data reveal a novel role of vinpocetine in reduction of pathogenesis of atherosclerosis, at least partially through suppressing LOX-1 signaling pathway. Given the excellent safety profile of vinpocetine, this study suggests vinpocetine may be a therapeutic candidate for treating atherosclerosis.

  18. Method of attenuation of electromagnetic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Reh, G.P.; Mawdsley, G.E.; Yaffe, M.J.

    1990-05-30

    A method for the protection of matter, including humans, by attenuation of electromagnetic radiation comprises providing the matter with a protective layer of an inorganic composition formed from at least two elements, or compounds thereof, selected from different specified groups. The elements provide complementary attenuation of the radiation, and may be selected to optimize protection against specific energy spectra. The inorganic composition may be in a carrier e.g. a polymer. The method may be used in a variety of ways e.g. in protection of humans from x-rays, gamma rays or other radiation, or in packaging applications, protection of equipment sensitive to radiation or the like. The inorganic composition comprises elements or compounds of Ac, Bi, Au, Pb, Hg, Pu, Po, Pa, Tl, Th and/or U together with elements or compounds of Sb, Ba, Cd, Ce, Cs, La, Pb, In, I, Ag, Te, Sn, W, Au, Ir, Hg, Os, Pt, Re, Ta and/or Tl. (author).

  19. Exercise Training During Bed Rest Attenuates Deconditioning

    Science.gov (United States)

    Greenleaf, J. E.; Hargens, Alan R. (Technical Monitor)

    1995-01-01

    A 30-day 6 deg. head-down bed rest study was conducted to evaluate high-intensity, short-duration, alternating isotonic cycle ergometer exercise (ITE) training and high-intensity intermittent isokinetic exercise (IKE) training regiments designed to maintain peak VO2 and muscle mass, strength, and endurance at ambulatory control levels throughout prolonged bed rest. Other elements of the deconditioning (acclimation) syndrome, such as proprioception, psychological performance, hypovolemia, water balance, body composition, and orthostatic tolerance, were also measured. Compared with response during bed rest of the no exercise (NOE) control group: the ITE training regimen (a) maintained work capacity (peak VO2), (b) maintained plasma and red cell volume, (c) induced positive body water balance, (d) decreased quality of sleep and mental concentration, and (e) had no effect on the decrease in orthostatic tolerance; the IKE training regimen (a) attenuated the decrease in peak VO2 by 50%, (b) attenuated loss of red cell volume by 40%, but had no effect on loss of plasma volume, (c) induced positive body water balance, (d) had no adverse effect on quality of sleep or concentration, and (e) had no effect on the decrease in orthostatic tolerance. These findings suggest that various elements of the deconditioning syndrome can be manipulated by duration and intensity of ITE or IKE training regiments, and that several different training protocols will be required to maintain or restore physiological and psychological performance of individuals confined to prolonged bed rest.

  20. Frequency ranges and attenuation of macroseismic effects

    Science.gov (United States)

    Tosi, Patrizia; De Rubeis, Valerio; Sbarra, Paola

    2017-09-01

    Macroseismic intensity is assessed on the basis of the effects caused by an earthquake. These effects reflect the expression of both the intensity and frequency of the ground motion, thus complicating prediction equation modelling. Here we analysed data of several macroseismic transitory effects caused by recent Italian earthquakes in order to study their attenuation as a function of magnitude and hypocentral distance and to obtain a specific prediction equation, of simple functional form, that could be applied to each of the effects under analysis. We found that the different attenuation behaviours could be clearly defined by the values of the specially formulated magnitude-distance scaling ratio (S), thus allowing to group the effects on the basis of the S value. The oscillation of hanging objects and liquids, together with the feeling of dizziness, were separated from most other variables, such as the effects of the earthquake on small objects, china and windows, which were caused by a vibration of higher frequency. Besides, the greater value of S, associated with the perception of the seismic sound, explained the peculiarity of this phenomenon. As a result, we recognized the frequency range associated with each effect through comparisons with the ground motion prediction equations and, in particular, with the 5 per cent damped horizontal response spectra. Here we show the importance of appropriately selecting the diagnostic elements to be used for intensity assessment in order to improve the correlation with ground motion.

  1. Glasses, Stress, Attenuation and Thermal Conductivity

    Science.gov (United States)

    Wu, Jiansheng; Yu, Clare

    2011-03-01

    A wide variety of amorphous materials exhibit similar behavior in their thermal properties. Examples include universal features in the specific heat,thermal conductivity, and ultrasonic attenuation. Recent experiments from the Parpia group at Cornell find that high stress silicon nitride thin film resonators exhibit a remarkably high Q factor, exceeding that of amorphous Si O2 by 2 to 3 orders of magnitude over a broad range of temperatures, and even exceeding that of single crystal silicon at room temperature. We present a model of why the stress reduces the attenuation. The basic assumption is that high stress increases the potential barriers of the excitations of defects that produce the loss, thus reducing the effective density of lossy fluctuators. We predict that high stress could lead to high thermal conductivity and low dielectric loss, making high stress SiN an excellent candidate as a substrate for integrated circuits. This work was supported by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA), through the Army Research Office.

  2. Omentin functions to attenuate cardiac hypertrophic response.

    Science.gov (United States)

    Matsuo, Kazuhiro; Shibata, Rei; Ohashi, Koji; Kambara, Takahiro; Uemura, Yusuke; Hiramatsu-Ito, Mizuho; Enomoto, Takashi; Yuasa, Daisuke; Joki, Yusuke; Ito, Masanori; Hayakawa, Satoko; Ogawa, Hayato; Kihara, Shinji; Murohara, Toyoaki; Ouchi, Noriyuki

    2015-02-01

    Cardiac hypertrophy occurs in many obesity-related conditions. Omentin is an adipose-derived plasma protein that is downregulated under obese conditions. Here, we investigated whether omentin modulates cardiac hypertrophic responses in vivo and in vitro. Systemic administration of an adenoviral vector expressing human omentin (Ad-OMT) to wild-type (WT) mice led to the attenuation of cardiac hypertrophy, fibrosis and ERK phosphorylation induced by transverse aortic constriction (TAC) or angiotensin II infusion. In cultured cardiomyocytes, stimulation with phenylephrine (PE) led to an increase in myocyte size, which was prevented by pretreatment with human omentin protein. Pretreatment of cardiomyocytes with omentin protein also reduced ERK phosphorylation in response to PE stimulation. Ad-OMT enhanced phosphorylation of AMP-activated protein kinase (AMPK) in the heart of WT mice after TAC operation. Blockade of AMPK activation by transduction with dominant-negative mutant forms of AMPK reversed the inhibitory effect of omentin on myocyte hypertrophy and ERK phosphorylation following PE stimulation. Moreover, fat-specific transgenic mice expressing human omentin showed reduced cardiac hypertrophy and ERK phosphorylation following TAC surgery compared to littermate controls. These data suggest that omentin functions to attenuate the pathological process of myocardial hypertrophy via the activation of AMPK in the heart, suggesting that omentin may represent a target molecule for the treatment of cardiac hypertrophy. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Effects of training on hearing protector attenuation

    Directory of Open Access Journals (Sweden)

    William J Murphy

    2011-01-01

    Full Text Available The effect of training instruction, whether presented as the manufacturer′s printed instructions, a short video training session specific to the product, or as a one-on-one training session was evaluated using four hearing protection devices with eight groups of subjects. Naïve subjects were recruited and tested using three different forms of training: written, video, and individual training. The group averages for A-weighted attenuation were not statistically significant when compared between the video or the written instruction conditions, regardless of presentation order. The experimenter-trained A-weighted attenuations were significantly greater than the written and video instruction for most of the protectors and groups. For each earplug, the noise reduction statistic for A-weighting (NRS A and the associated confidence intervals were calculated for the 80 th and 20 th percentiles of protection. Across subject groups for each protector, the differences between NRS A ratings were found to be not statistically significant. Several comparisons evaluating the order of testing, the type of testing, and statistical tests of the performance across the groups are presented.

  4. Engineering a Light-Attenuating Artificial Iris.

    Science.gov (United States)

    Shareef, Farah J; Sun, Shan; Kotecha, Mrignayani; Kassem, Iris; Azar, Dimitri; Cho, Michael

    2016-04-01

    Discomfort from light exposure leads to photophobia, glare, and poor vision in patients with congenital or trauma-induced iris damage. Commercial artificial iris lenses are static in nature to provide aesthetics without restoring the natural iris's dynamic response to light. A new photo-responsive artificial iris was therefore developed using a photochromic material with self-adaptive light transmission properties and encased in a transparent biocompatible polymer matrix. The implantable artificial iris was designed and engineered using Photopia, a class of photo-responsive materials (termed naphthopyrans) embedded in polyethylene. Photopia was reshaped into annular disks that were spin-coated with polydimethylsiloxane (PDMS) to form our artificial iris lens of controlled thickness. Activated by UV and blue light in approximately 5 seconds with complete reversal in less than 1 minute, the artificial iris demonstrates graded attenuation of up to 40% of visible and 60% of UV light. There optical characteristics are suitable to reversibly regulate the incident light intensity. In vitro cell culture experiments showed up to 60% cell death within 10 days of exposure to Photopia, but no significant cell death observed when cultured with the artificial iris with protective encapsulation. Nuclear magnetic resonance spectroscopy confirmed these results as there was no apparent leakage of potentially toxic photochromic material from the ophthalmic device. Our artificial iris lens mimics the functionality of the natural iris by attenuating light intensity entering the eye with its rapid reversible change in opacity and thus potentially providing an improved treatment option for patients with iris damage.

  5. Evaluation of left renal vein entrapment using multidetector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Poyraz, Ahmet K.; Onur, Mehmet R. [Dept. of Radiology, Firat Univ. School of Medicine, Elazig (Turkey)], e-mail: akursadpoyraz@yahoo.com.tr; Firdolas, Fatih [Dept. of Urology, Firat Univ. School of Medicine, Elazig (Turkey); Kocakoc, Ercan [Dept. of Radiology, Bezmialem Vakif Univ., School of Medicine, Istanbul (Turkey)

    2013-03-15

    Background: Nutcracker syndrome, also called left renal vein entrapment syndrome, is a cause of non-glomerular hematuria with difficulties in diagnosis. Multidetector computed tomography (MDCT) is a powerful tool to prevent unnecessary diagnostic procedures. Purpose: To retrospectively determine the prevalence of nutcracker phenomenon and nutcracker syndrome seen in MDCT in consecutive patients. Material and Methods: The institutional review board approved the study and waived the requirement for informed consent. Abdominal contrast-enhanced MDCT scans were reviewed from 1000 consecutive patients. MDCT scan assessment included renal vein diameter measurements and evaluation for the presence of anterior or posterior left renal vein entrapment. Electronic medical records and urine analysis reports of patients with left renal vein entrapment were reviewed. Student's t test was used to assess differences in renal vein diameter in patients with left renal vein entrapment. Results: Left renal vein entrapment was observed in 10.9% (109), retroaortic left renal vein in 6.5% (65), entrapment of left renal vein between superior mesenteric artery and aorta in 4.1% (41), and circumaortic left renal vein in 0.3% (3) of patients. Mean diameters of right (8.8 {+-} 1.9 mm) and unentrapped left (8.9 {+-} 1.8 mm) renal veins were not significantly different (P = 0.1). The mean diameter of anterior entrapped left renal veins (10.3 {+-} 2 mm) was significantly greater (P = 0.04) than contralateral renal veins (8.6 {+-} 2.1 mm) in their widest portion. In 8.8% of patients with the left renal vein entrapment, urine analysis showed isomorphic hematuria or proteinuria with no other known cause. Varicocele and pelvic congestion were seen in 5.5% of patients with the left renal vein entrapment. Conclusion: Left renal vein entrapment is not a rare entity and renal nutcracker phenomenon might be underdiagnosed.

  6. UFO in the Left Atrium: How to Capture Metal Debris Floating in the Left Atrium.

    Science.gov (United States)

    Fassini, Gaetano; Moltrasio, Massimo; Conti, Sergio; Biagioli, Viviana; Tondo, Claudio

    2016-06-01

    Electrophysiology procedures involving left atrium navigation are becoming more frequent, mostly due to the increase of atrial fibrillation ablation. Mapping catheters of different shapes and size as well as dedicated sheaths are mandatory tools for the accomplishment of procedural end point. Therefore, technical issues are expected, usually unrelated to significant risk. However, any accidental intra-atrial device loss of integrity implies a risk of cerebrovascular embolization. The lack of clear evidence on how to manage these events and the need for a quick solution complicate the scenario. We report an empirical solution in the case of debris floating in the left atrium. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  7. Cardio-protecteffect of qiliqiangxin capsule on left ventricular remodeling, dysfunction and apoptosis in heart failure rats after chronic myocardial infarction.

    Science.gov (United States)

    Liang, Tuo; Zhang, Yuhui; Yin, Shijie; Gan, Tianyi; An, Tao; Zhang, Rongcheng; Wang, Yunhong; Huang, Yan; Zhou, Qiong; Zhang, Jian

    2016-01-01

    Qiliqiangxin (QL) capsule is a traditional Chinese medicine which has been approved for the treatment of chronic heart failure. Evidences proved that QL capsules further reduced the NT-proBNP levels and improved left ventricular ejection fraction in CHF patients but the evidence supporting its underlying mechanism is still unclear. Myocardial infarction (MI) -Heart failure (HF) Sprague-Dawley ratsmodel and neonatal rat cardiac myocytes (NRCMs) were used. Animals were assigned into 4 groups, normal group (n=6), shame-operation group (n=6), MI rats 4 weeks after left anterior descending coronary artery ligation were randomized into vehicle group (n=8), QL group (n=8). QL significantly attenuated cardiac dysfunction and ventricle remodeling as echocardiography and hemodynamic measurements showed improvement in left ventricular ejection fraction, fractional shortening, ±dp/dt and left ventricular end diastolic and systolic diameters in QL treated group compared with the vehicle group. Improvements ininterstitial fibrosisand mitochondrial structures were also exhibited by Sirius Red staining, RT-PCR and electron microscopy. QL treatment improved apoptosis and VEGF expression in rats marginal infract area. Complementary experiments analyzed the improved apoptosis and up-regulate of VEGF in ischemia-hypoxia cultivated NRCMs is in an Akt dependent manner and can be reversed by Akt inhibitor. QL capsule can improve cardiac dysfunction and ventricular remodeling in MI-HF ratsmodel, this cardiac protective efficacy may be concerned with attenuated apoptosis and cardiac fibrosis. Up-regulated VEGF expression and Akt phosphorylation may take part in this availability.

  8. Studies on attenuation of rotavirus. A comparison in piglets between virulent virus and its attenuated derivative.

    Science.gov (United States)

    Tzipori, S; Unicomb, L; Bishop, R; Montenaro, J; Vaelioja, L M

    1989-01-01

    The development of rotavirus vaccines against acute gastroenteritis for human infants has been accorded a very high priority. Several vaccine candidates all of which are live cultivated strains of animal origin have been tested in humans. However the nature of attenuation of these viruses for humans is unknown. In this study we have attenuated a pig rotavirus by 15 sequential passages in cell culture after which the virus no longer causes diarrhoea in piglets. The pathogenesis of infection of the attenuated rotavirus strain (AT/76 P15) in gnotobiotic piglets was compared with that of the virulent parent strain (AT/76). The pattern of virus replication in the small intestine was judged by histology, disaccharidase assay, immunoperoxidase labelling of gut sections using group A specific rotavirus antibody, and rotavirus antigen assay of gut contents. The parent strain caused variable but extensive infection that resulted in the complete destruction of mature small intestinal enterocytes and villous contraction within 3 days. Membrane bound digestive enzymes were lost, and profound watery diarrhoea and dehydration resulted in causing piglets to become moribund. In contrast attenuated virus appeared to propagate at a much slower pace. Fewer infected epithelial cells were detected at any one time. Destruction of enterocytes was never extensive enough to cause marked mucosal changes in histology. Membrane bound digestive enzymes remained near normal levels and there was little or no diarrhoea. Virus replication ceased after 6 days. It is concluded that attenuation of the porcine rotavirus strain studied was associated with its decreased ability to propagate in enterocytes after adaption to culture.

  9. An acoustic eikonal equation for attenuating VTI media

    KAUST Repository

    Hao, Qi

    2016-09-06

    We present an acoustic eikonal equation governing the complex-valued travel time of P-waves in attenuating, transversely isotropic media with a vertical symmetry axis (VTI). This equation is based on the assumption that the Pwave complex-valued travel time is independent of the Swave velocity parameter v in Thomsen\\'s notation and the attenuation coefficient A in the Thomsen-type notation for attenuating VTI media. We combine perturbation theory and Shanks transform to develop practical approximations to the attenuating acoustic eikonal equation, capable of admitting analytical description of the attenuation in homogeneous media. For a horizontal, attenuating VTI layer, we also derive non-hyperbolic approximations for the real and imaginary parts of the complex-valued reflection travel time.

  10. Left unilateral neglect as a disconnection syndrome. : Disconnection in left neglect

    OpenAIRE

    Bartolomeo, Paolo; Thiebaut de Schotten, Michel; Doricchi, Fabrizio

    2007-01-01

    International audience; Unilateral spatial neglect is a disabling neurological condition that typically results from right hemisphere damage. Neglect patients are unable to take into account information coming from the left side of space. The study of neglect is important for understanding the brain mechanisms of spatial cognition, but its anatomical correlates are currently the object of intense debate. We propose a reappraisal of the contribution of disconnection factors to the pathophysiol...

  11. Left Atrial Performance in the Course of Hypertrophic Cardiomyopathy: Relation to Left Ventricular Hypertrophy and Fibrosis.

    Science.gov (United States)

    Kowallick, Johannes T; Silva Vieira, Miguel; Kutty, Shelby; Lotz, Joachim; Hasenfu, Gerd; Chiribiri, Amedeo; Schuster, Andreas

    2017-03-01

    Hypertrophic cardiomyopathy (HCM) is associated with left atrial (LA) functional abnormalities. The determinants and the degree of LA dysfunction in the course of HCM are not fully understood. We aimed to characterize LA mechanics in HCM, according to the extent of left ventricular (LV) hypertrophy and fibrosis. Seventy-three HCM patients and 23 age- and sex-matched controls underwent cardiovascular magnetic resonance imaging including late gadolinium enhancement (LGE). LA reservoir, conduit, and contractile functions were quantified by fractional volume changes and cardiovascular magnetic resonance feature-tracking-derived strain and strain rate. In multivariable regression, LA mechanics were associated with the extent of LV LGE (P = 0.033 to P < 0.001), but not with the LV mass extent or maximum wall thickness (P = 0.108 to P = 0.964). Left atrial function decreased according to the increase in extent of LV fibrosis (non-LGE; mild LGE ≤ 10%; intermediate LGE 11%-19%; severe LGE ≥ 20%). Compared with healthy controls, LA conduit function was impaired in HCM with no LGE already (LA emptying fraction conduit: 32% ± 7% vs 26 ± 14, P = 0.037). Conversely, LA contractile booster pump function was impaired in HCM with severe LGE only (LA emptying fraction booster: 40% ± 8% vs 20% ± 10%, P < 0.001; for controls vs LGE ≥ 20%, respectively). Left atrial functional abnormalities are associated with LV fibrosis, but not with LV hypertrophy. While LA conduit function is impaired in early HCM stages as represented by mild or absent LV fibrosis, LA contractile function is impaired later in the course of disease progression as demonstrated by the presence of severe LV fibrosis only. These novel markers of LA performance may potentially proof useful for disease staging and early detection of cardiac deterioration.

  12. Intradural herniation of a thoracic disc presenting as left radicular pain and left drop foot

    Directory of Open Access Journals (Sweden)

    Takuji Matsumoto

    2015-09-01

    Full Text Available Intradural disc herniation is a rare pathological entity. Normally, it is associated with severe neurological deficits, including compression syndrome of the spinal cord or cauda equina. Intradural disc herniations comprise 0.26% to 030% of all herniated discs. Overall, 5% are found in the thoracic region, 3% in the cervical region, and 92% in the lumbar region. Although intradural disc herniation may be suspected preoperatively because of myelography, computed tomography, and magnetic resonance imaging results, establishing the diagnosis before surgery is difficult. We report a patient with thoracic intradural disc herniation at T11-12 who presented with left radicular pain and left drop foot. Preoperative magnetic resonance imaging, computed tomography, and myelography failed to demonstrate an intradural lesion. The patient underwent T11-L1 dorsal hemilaminectomy with lateral extension to the left side. The herniation was identified only intraoperatively during inspection of the thecal sac. The disc was removed surgically, and the operation was performed safely under intraoperative spinal cord monitoring. The patient had a good neurological recovery. She remains pain-free 2 years after the surgery.

  13. Left unilateral neglect as a disconnection syndrome.

    Science.gov (United States)

    Bartolomeo, Paolo; Thiebaut de Schotten, Michel; Doricchi, Fabrizio

    2007-11-01

    Unilateral spatial neglect is a disabling neurological condition that typically results from right hemisphere damage. Neglect patients are unable to take into account information coming from the left side of space. The study of neglect is important for understanding the brain mechanisms of spatial cognition, but its anatomical correlates are currently the object of intense debate. We propose a reappraisal of the contribution of disconnection factors to the pathophysiology of neglect based on a review of animal and patient studies. These indicate that damage to the long-range white matter pathways connecting parietal and frontal areas within the right hemisphere may constitute a crucial antecedent of neglect. Thus, neglect would not result from the dysfunction of a single cortical region but from the disruption of large networks made up of distant cortical regions. In this perspective, we also reexamined the possible contribution to neglect of interhemispheric disconnection. The reviewed evidence, often present in previous studies but frequently overlooked, is consistent with the existence of distributed cortical networks for orienting of attention in the normal brain, has implications for theories of neglect and normal spatial processing, opens perspectives for research on brain-behavior relationships, and suggests new possibilities for patient diagnosis and rehabilitation.

  14. Left ventricular function studied with MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Juergens, Kai Uwe; Fischbach, Roman [University of Muenster, Department of Clinical Radiology, Muenster (Germany)

    2006-02-01

    Accurate determination of left ventricular (LV) myocardial function is fundamental for clinical diagnosis, risk stratification, and estimation of prognosis in patients with ischemic and nonischemic cardiomyopathy. Primarily, multi-detector-row spiral CT (MDCT) of the heart aimed at detecting coronary artery obstruction and cardiac morphology. Multiple studies have demonstrated that retrospectively, ECG-gated MDCT determination of LV volumes and consequently global LV function parameters is feasible in good agreement with established imaging modalities such as cineventriculography, echocardiography, and cine magnetic resonance imaging (CMR). Post-processing tools allow fast and semi-automatic determination of LV function parameters from MDCT data in analogy to known CMR evaluation approaches. Although MDCT is not considered to be first-line modality for LV function assessment, this technique provides accessory dynamic information in patients undergoing MDCT coronary angiography, contributing to combined assessment of cardiac morphology and function without need of additional radiation exposure. MDCT regional LV wall motion analysis at rest is feasible, but further improvement in temporal resolution seems mandatory to match results obtained from competing modalities. This paper will discuss the diagnostic potential of MDCT for assessment of LV function with regards to accuracy and clinical applications, as well as limitations, particularly in comparison with CMR as modality of reference. (orig.)

  15. Left ventricular noncompaction: Clinical-echocardiographic study

    Directory of Open Access Journals (Sweden)

    Nikolić Aleksandra

    2012-01-01

    Full Text Available Background/Aim. Left ventricular noncompaction (LVNC is a disorder in endomyocardial morphogenesis, seen either isolated (in the absence of other cardiac anomalies or in association with congenital heart disease and some neuromuscular diseases. Intrauterine arrest of the compaction of myocardial fibers is postulated to be the reason of LVNC. Recognition of this condition is extremely important due to its high mortality and morbidity that lead to progressive heart failure, ventricular arrhythmias and thromboembolic events. The aim of this study was to determine the prevalence and clinical presentation of LVNC among consecutive outpatients according to clinical and echocardiographyic findings. Methode. A total of 3,854 consecutive patients examined at the Institute for Cardiovascular Diseases within a period January 2006 - January 2007 were included in the study. All the patients underwent echocardiographic examination using the same equipment (Vivid 7, GE Medical System. Echocardiographic parameters and clinical presentation in patients with echocardiographic criteria for LVNC were analyzed. Results. Analyzing 3,854 consecutive outpatients, using two-dimensional Color Doppler echocardiography from January 2006 to January 2007, 12 patients met the criteria for LVNC. Seven of them were male. The mean age at diagnosis was 45 ± 15 years. Analyzing clinical manifestation of LVNC it was found that seven patients had signs of heart failure, six had arrhythmias with no embolic events. Conclusion. Our results suggest that the real prevalence of LVNC may be higher than expected. New studies have to be done to solve this problem.

  16. TOOL USE DISORDERS AFTER LEFT BRAIN DAMAGE

    Directory of Open Access Journals (Sweden)

    Josselin eBaumard

    2014-05-01

    Full Text Available In this paper we review studies that investigated tool use disorders in left-brain damaged (LBD patients over the last thirty years. Four tasks are classically used in the field of apraxia: Pantomime of tool use, single tool use, real tool use and mechanical problem solving. Our aim was to address two issues, namely, (1 the role of mechanical knowledge in real tool use and (2 the cognitive mechanisms underlying pantomime of tool use, a task widely employed by clinicians and researchers. To do so, we extracted data from 36 papers and computed the difference between healthy subjects and LBD patients. On the whole, pantomime of tool use is the most difficult task and real tool use is the easiest one. Moreover, associations seem to appear between pantomime of tool use, real tool use and mechanical problem solving. These results suggest that the loss of mechanical knowledge is critical in LBD patients, even if all of those tasks (and particularly pantomime of tool use might put differential demands on semantic memory and working memory.

  17. Electrocardiographic patterns during left ventricular epicardial pacing.

    Science.gov (United States)

    Jastrzebski, Marek; Fijorek, Kamil; Czarnecka, Danuta

    2012-11-01

    There is a paucity of data concerning the use of QRS morphology patterns for identifying pacing sites during left ventricle (LV)-only epicardial pacing in patients with a biventricular device. The objective of this study was to identify QRS patterns during LV-only pacing, and to establish their relationship with LV lead position. In addition, to validate the diagnostic performance of such electrocardiogram (ECG) patterns for predicting posterolateral versus anterior and apical versus nonapical LV pacing site. The study retrospectively analyzed data from 376 cardiac resynchronization therapy device patients. Data analyzed included ECGs registered during LV-only VVI pacing, fluoroscopic projections, and lateral chest roentgenograms that documented postimplantation LV lead position. Phase one of the study involved categorization of the ECG patterns of the first 66 study cases. Phase two of the study examined the association between ECG pattern and different LV lead positions. As the LV epicardial pacing site became more anteroapical, the LV-only paced QRS complexes in the precordial leads became more negative. Three ECG patterns were identified (posterolateral, intermediate, and anteroapical), and their distribution was found to be associated with LV lead position (P anteroapical ECG pattern was associated with LV leads in anteroapical segments (specificity of 98.5%, accuracy of 89.1% for predicting an anteroapical pacing site). Posterolateral and anteroapical ECG patterns are highly predictive of LV lead position. ©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.

  18. What's 'left' in the 'Garden of Sweden'?

    Science.gov (United States)

    Olsen, Gregg M

    2013-01-01

    Liberalization, restructuring, and retrenchment have been underway in Sweden for more than two decades and have rapidly accelerated under the current non-socialist coalition government. It is uncertain how much of the Swedish social policy model is "left" now, in terms of both what remains of it and its political character. A cross-temporal look at developments within Sweden reveals striking and continual rollbacks and marketization since the 1990s. However, this view must be qualified, both because Sweden's undisputed descent is from a comparatively lofty position and because there have been some noteworthy, but often ignored, gains even amidst marked decline over the past few decades. A cross-national examination indicates that, despite rapidly rising rates of income and wealth inequality, Sweden remains an egalitarian leader in several respects. This view must be qualified, too, because, while it continues to routinely out-perform Anglo nations such as Canada, the United Kingdom, and the United States, Sweden is less often, and less notably, distinct from several of its continental counterparts in Europe now. Moreover, the foundation of the model, labor strength, has been significantly undermined.

  19. Cilia in Left-Right Symmetry Breaking.

    Science.gov (United States)

    Shinohara, Kyosuke; Hamada, Hiroshi

    2017-10-03

    Visceral organs of vertebrates show left-right (L-R) asymmetry with regard to their position and morphology. Cilia play essential role in generating L-R asymmetry. A number of genes required for L-R asymmetry have now been identified in vertebrates, including human, many of which contribute to the formation and motility of cilia. In the mouse embryo, breaking of L-R symmetry occurs in the ventral node, where two types of cilia (motile and immotile) are present. Motile cilia are located at the central region of the node, and generate a leftward fluid flow. These motile cilia at the node are unique in that they rotate in the clockwise direction, unlike other immotile cilia such as airway cilia that show planar beating. The second type of cilia essential for L-R asymmetry is immotile cilia that are peripherally located immotile cilia. They sense a flow-dependent signal, which is either chemical or mechanical in nature. Although Ca 2+ signaling is implicated in flow sensing, the precise mechanism remains unknown. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

  20. Surface Wave Attenuation in the Tibetan Plateau from Ambient Noise

    Science.gov (United States)

    2015-08-31

    AFRL-RV-PS- TR-2015-0150 AFRL-RV-PS- TR-2015-0150 SURFACE WAVE ATTENUATION IN THE TIBETAN PLATEAU FROM AMBIENT NOISE University of Illinois at...DATES COVERED (From - To) 01 May 2012 to 31 Aug 2015 4. TITLE AND SUBTITLE Surface Wave Attenuation in the Tibetan Plateau from Ambient Noise 5a...extract amplitude information from the empirical Green functions (EGF) derived from ambient noise correlations and to map the attenuation of the

  1. Usage of attenuation coefficients of some tissue-equivalent materials

    OpenAIRE

    TANIR, Ayşe Güneş; KETENCİ, Fatma Serap; BÖLÜKDEMİR, Mustafa Hicabi

    2015-01-01

    The total attenuation coefficients of 11 biological targets against photon energies were plotted within the energy range 1-10 MeV. From these plots a possible equation describing the relationship between photon energy and the total attenuation coefficient was derived. The suggested equation is mu/ rho = 0.0696/ surd E. To test the validity of the equation and to compare the results of the total attenuation coefficients of 3 tissue-equivalent materials (bolus, rice grains, and boiled rice) th...

  2. An Approximate Method for the Acoustic Attenuating VTI Eikonal Equation

    KAUST Repository

    Hao, Q.

    2017-05-26

    We present an approximate method to solve the acoustic eikonal equation for attenuating transversely isotropic media with a vertical symmetry axis (VTI). A perturbation method is used to derive the perturbation formula for complex-valued traveltimes. The application of Shanks transform further enhances the accuracy of approximation. We derive both analytical and numerical solutions to the acoustic eikonal equation. The analytic solution is valid for homogeneous VTI media with moderate anellipticity and strong attenuation and attenuation-anisotropy. The numerical solution is applicable for inhomogeneous attenuating VTI media.

  3. Imaging Rayleigh Wave Attenuation Beneath North America with USArray

    Science.gov (United States)

    Dalton, C. A.; Bao, X.; Jin, G.; Gaherty, J. B.

    2015-12-01

    The EarthScope USArray provides an opportunity to obtain detailed images of the continental upper mantle at an unprecedented scale. The majority of mantle models derived from USArray data to date contain spatial variations in seismic-wave speed; however, in many cases these data sets do not by themselves allow a non-unique interpretation. Joint interpretation of seismic attenuation and velocity models can improve upon the interpretations based only on velocity. Surface-wave amplitudes are sensitive to factors in addition to attenuation, including source excitation, focusing by elastic structure, and local site amplification. Because of the difficulty of isolating attenuation from these other factors, little is known about the attenuation structure of the North American upper mantle. In this study, Rayleigh wave travel time and amplitude in the period range 25-100 s are measured using an interstation cross-correlation technique. We consider three different approaches for separating the effects of local site amplification and attenuation on the amplitude measurements. The attenuation values determined with these three approaches contain the same first-order features, which gives us confidence that these features are robust: high attenuation in the western U.S. and low attenuation in the central and eastern U.S., with slightly higher attenuation along the eastern seaboard. However, we also identify several areas where we suspect the imaged attenuation values reflect unmodelled focusing effects rather than anelastic attenuation. We therefore identify attenuation values that are likely contaminated by unmodelled focusing effects using the Laplacian of the phase-velocity map, eliminate those values, and generate 2-D attenuation maps through a regional average of the remaining values. We also investigate the range of intrinsic shear-attenuation values that are suggested by the Rayleigh wave attenuation maps at periods between 40 and 80 s. This preliminary model is the

  4. Attenuation characteristic of UWB signals propagation in free space

    Science.gov (United States)

    Li, Meng; Huang, Zhonghua

    2016-10-01

    Researching attenuation characteristic of UWB signals propagation in free-space is necessary for ultra-wideband (UWB) radio fuze optimized design. Research attenuation characteristic of UWB signals propagation in free space can be achieved by learning attenuation characteristic of radio waves propagation in free-space and UWB signal power spectral density. 50ps, 100ps and 200ps of pulse width UWB fuze transmission narrow pulse signal propagation in free-space are simulated and analyzed. The attenuation of UWB signals at 3m, 6m and 9m are contrasted. The simulation, analysis and contrast is theoretical basis of UWB radio fuze optimized design.

  5. Immersing lungs in hydrogen-rich saline attenuates lung ischaemia-reperfusion injury.

    Science.gov (United States)

    Takahashi, Mamoru; Chen-Yoshikawa, Toyofumi F; Saito, Masao; Tanaka, Satona; Miyamoto, Ei; Ohata, Keiji; Kondo, Takeshi; Motoyama, Hideki; Hijiya, Kyoko; Aoyama, Akihiro; Date, Hiroshi

    2017-03-01

    Anti-oxidant effects of hydrogen have been reported in studies examining ischaemia-reperfusion injury (IRI). In this study, we evaluated the therapeutic efficacy of immersing lungs in hydrogen-rich saline on lung IRI. Lewis rats were divided into three groups: (i) sham, (ii) normal saline and (iii) hydrogen-rich saline. In the first experiment, the left thoracic cavity was filled with either normal saline or hydrogen-rich saline for 1 h. Then, we measured the hydrogen concentration in the left lung using a sensor gas chromatograph ( N = 3 per group). In the second experiment, lung IRI was induced by occlusion of the left pulmonary hilum for 1 h, followed by reperfusion for 3 h. During the ischaemic period, the left thoracic cavity was filled with either normal saline or hydrogen-rich saline. After reperfusion, we assessed lung function, histological changes and cytokine production ( N = 5-7 per group). Immersing lungs in hydrogen-rich saline resulted in an elevated hydrogen concentration in the lung (6.9 ± 2.9 μmol/1 g lung). After IRI, pulmonary function (pulmonary compliance and oxygenation levels) was significantly higher in the hydrogen-rich saline group than in the normal saline group ( P  hydrogen-rich saline group than in the normal saline group ( P  hydrogen-rich saline delivered hydrogen into the lung and consequently attenuated lung IRI. Hydrogen-rich solution appears to be a promising approach to managing lung IRI.

  6. Enhanced Attenuation Technologies: Passive Soil Vapor Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Vangelas, K.; Looney, B.; Kamath, R.; Adamson, D.; Newell, C.

    2010-03-15

    Passive soil vapor extraction (PSVE) is an enhanced attenuation (EA) approach that removes volatile contaminants from soil. The extraction is driven by natural pressure gradients between the subsurface and atmosphere (Barometric Pumping), or by renewable sources of energy such as wind or solar power (Assisted PSVE). The technology is applicable for remediating sites with low levels of contamination and for transitioning sites from active source technologies such as active soil vapor extraction (ASVE) to natural attenuation. PSVE systems are simple to design and operate and are more cost effective than active systems in many scenarios. Thus, PSVE is often appropriate as an interim-remedial or polishing strategy. Over the past decade, PSVE has been demonstrated in the U.S. and in Europe. These demonstrations provide practical information to assist in selecting, designing and implementing the technology. These demonstrations indicate that the technology can be effective in achieving remedial objectives in a timely fashion. The keys to success include: (1) Application at sites where the residual source quantities, and associated fluxes to groundwater, are relatively low; (2) Selection of the appropriate passive energy source - barometric pumping in cases with a deep vadose zone and barrier (e.g., clay) layers that separate the subsurface from the atmosphere and renewable energy assisted PSVE in other settings and where higher flow rates are required. (3) Provision of sufficient access to the contaminated vadose zones through the spacing and number of extraction wells. This PSVE technology report provides a summary of the relevant technical background, real-world case study performance, key design and cost considerations, and a scenario-based cost evaluation. The key design and cost considerations are organized into a flowchart that dovetails with the Enhanced Attenuation: Chlorinated Organics Guidance of the Interstate Technology and Regulatory Council (ITRC). The PSVE

  7. CT Attenuation Analysis of Carotid Intraplaque Hemorrhage.

    Science.gov (United States)

    Saba, L; Francone, M; Bassareo, P P; Lai, L; Sanfilippo, R; Montisci, R; Suri, J S; De Cecco, C N; Faa, G

    2017-11-30

    Intraplaque hemorrhage is considered a leading parameter of carotid plaque vulnerability. Our purpose was to assess the CT characteristics of intraplaque hemorrhage with histopathologic correlation to identify features that allow for confirming or ruling out the intraplaque hemorrhage. This retrospective study included 91 patients (67 men; median age, 65 ± 7 years; age range, 41-83 years) who underwent CT angiography and carotid endarterectomy from March 2010 to May 2013. Histopathologic analysis was performed for the tissue characterization and identification of intraplaque hemorrhage. Two observers assessed the plaque's attenuation values by using an ROI (≥ 1 and ≤2 mm2). Receiver operating characteristic curve, Mann-Whitney, and Wilcoxon analyses were performed. A total of 169 slices were assessed (59 intraplaque hemorrhage, 63 lipid-rich necrotic core, and 47 fibrous); the average values of the intraplaque hemorrhage, lipid-rich necrotic core, and fibrous tissue were 17.475 Hounsfield units (HU) and 18.407 HU, 39.476 HU and 48.048 HU, and 91.66 HU and 93.128 HU, respectively, before and after the administration of contrast medium. The Mann-Whitney test showed a statistically significant difference of HU values both in basal and after the administration of contrast material phase. Receiver operating characteristic analysis showed a statistical association between intraplaque hemorrhage and low HU values, and a threshold of 25 HU demonstrated the presence of intraplaque hemorrhage with a sensitivity and specificity of 93.22% and 92.73%, respectively. The Wilcoxon test showed that the attenuation of the plaque before and after administration of contrast material is different (intraplaque hemorrhage, lipid-rich necrotic core, and fibrous tissue had P values of .006, .0001, and .018, respectively). The results of this preliminary study suggest that CT can be used to identify the presence of intraplaque hemorrhage according to the attenuation. A threshold of 25

  8. Anti-inflammatory effects of triptolide improve left ventricular function in a rat model of diabetic cardiomyopathy

    Science.gov (United States)

    2013-01-01

    Aims Given the importance of inflammation in the onset and progression of diabetic cardiomyopathy, we investigated the potential protective effects of triptolide, an anti-inflammatory agent, in streptozotocin-induced diabetic rat model and in H9c2 rat cardiac cells exposed to high glucose. Methods and results Diabetic rats were treated with triptolide (100, 200, or 400 μg/kg/day respectively) for 6 weeks. At the end of this study, after cardiac function measurements were performed, rats were sacrificed and their hearts were harvested for further histologic and molecular biologic analysis. Enhanced activity and expression of nuclear factor-kappaB (NF-κB) p65 in diabetic hearts were associated with increased inflammatory response, as demonstrated by increased pro-inflammatory cytokines, cell adhesion molecules and invading inflammatory cells, as well as increased fibrosis, in line with impaired left ventricular function. Triptolide attenuated these morpho-functional alterations. Furthermore, triptolide (20 ng/ml) also attenuated high glucose-induced inflammation in H9c2 rat cardiac cells. Conclusion Our data demonstrate that anti-inflammatory effects of triptolide involving the NF-κB signaling pathway can improve left ventricular function under diabetic conditions, suggesting triptolide treatment might be beneficial in diabetic cardiomyopathy. PMID:23530831

  9. On left (θ,ϕ-derivations in BCI-algebras

    Directory of Open Access Journals (Sweden)

    G. Muhiuddin

    2014-07-01

    Full Text Available The notion of (regular left (θ,ϕ-derivations of a BCI-algebra is introduced, some useful examples are discussed, and related properties are investigated. Conditions for a left (θ,ϕ-derivation to be regular are provided. The concepts of a d(θ,ϕ-invariant left (θ,ϕ-derivation and θ-ideal are introduced, and their relations are discussed. Furthermore, some more interesting results are established.

  10. Rupture of the left atrial roof due to blunt trauma.

    Science.gov (United States)

    Ryu, Dae Woong; Lee, Sam Youn; Lee, Mi Kyung

    2013-11-01

    Cardiac rupture after blunt trauma is rare and associated with high mortality. The anatomic pattern of blunt cardiac rupture has been demonstrated with the right cardiac chambers more frequently affected than the left. Furthermore, left atrial injury is usually restricted to the atrial appendage and the pulmonary vein-atrial junction. Herein, we report the first case of a 61-year old man with a rupture of the left atrial roof after blunt trauma with minimal thoracic injury.

  11. Rupture of the left atrial roof due to blunt trauma

    OpenAIRE

    Ryu, Dae Woong; Lee, Sam Youn; Lee, Mi Kyung

    2013-01-01

    Cardiac rupture after blunt trauma is rare and associated with high mortality. The anatomic pattern of blunt cardiac rupture has been demonstrated with the right cardiac chambers more frequently affected than the left. Furthermore, left atrial injury is usually restricted to the atrial appendage and the pulmonary vein–atrial junction. Herein, we report the first case of a 61-year old man with a rupture of the left atrial roof after blunt trauma with minimal thoracic injury.

  12. Lexical Information and Processing Left Clause Boundaries in Japanese

    OpenAIRE

    村岡, 諭

    2005-01-01

    The present study investigates the effects of lexical information in processing left clause boundaries in Japanese. Miyamoto (2002) proposed a mechanism in which the parser creates a left clause boundary before it processes a verb by using information of case-markers. I claim that the parser uses not only information of case-markers but also lexical information in processing left clause boundaries in Japanese. A self-paced reading experiment is conducted to verify this claim. The results are ...

  13. Damage to the Left Precentral Gyrus Is Associated With Apraxia of Speech in Acute Stroke.

    Science.gov (United States)

    Itabashi, Ryo; Nishio, Yoshiyuki; Kataoka, Yuka; Yazawa, Yukako; Furui, Eisuke; Matsuda, Minoru; Mori, Etsuro

    2016-01-01

    Apraxia of speech (AOS) is a motor speech disorder, which is clinically characterized by the combination of phonemic segmental changes and articulatory distortions. AOS has been believed to arise from impairment in motor speech planning/programming and differentiated from both aphasia and dysarthria. The brain regions associated with AOS are still a matter of debate. The aim of this study was to address this issue in a large number of consecutive acute ischemic stroke patients. We retrospectively studied 136 patients with isolated nonlacunar infarcts in the left middle cerebral artery territory (70.5±12.9 years old, 79 males). In accordance with speech and language assessments, the patients were classified into the following groups: pure form of AOS (pure AOS), AOS with aphasia (AOS-aphasia), and without AOS (non-AOS). Voxel-based lesion-symptom mapping analysis was performed on T2-weighted images or fluid-attenuated inversion recovery images. Using the Liebermeister method, group-wise comparisons were made between the all AOS (pure AOS plus AOS-aphasia) and non-AOS, pure AOS and non-AOS, AOS-aphasia and non-AOS, and pure AOS and AOS-aphasia groups. Of the 136 patients, 22 patients were diagnosed with AOS (7 patients with pure AOS and 15 patients with AOS-aphasia). The voxel-based lesion-symptom mapping analysis demonstrated that the brain regions associated with AOS were centered on the left precentral gyrus. Damage to the left precentral gyrus is associated with AOS in acute to subacute stroke patients, suggesting a role of this brain region in motor speech production. © 2015 American Heart Association, Inc.

  14. Early Left-Hemispheric Dysfunction of Face Processing in Congenital Prosopagnosia: An MEG Study

    Science.gov (United States)

    Dobel, Christian; Putsche, Christian; Zwitserlood, Pienie; Junghöfer, Markus

    2008-01-01

    Background Congenital prosopagnosia is a severe face perception impairment which is not acquired by a brain lesion and is presumably present from birth. It manifests mostly by an inability to recognise familiar persons. Electrophysiological research has demonstrated the relevance to face processing of a negative deflection peaking around 170 ms, labelled accordingly as N170 in the electroencephalogram (EEG) and M170 in magnetoencephalography (MEG). The M170 was shown to be sensitive to the inversion of faces and to familiarity-two factors that are assumed to be crucial for congenital prosopagnosia. In order to locate the cognitive dysfunction and its neural correlates, we investigated the time course of neural activity in response to these manipulations. Methodology Seven individuals with congenital prosopagnosia and seven matched controls participated in the experiment. To explore brain activity with high accuracy in time, we recorded evoked magnetic fields (275 channel whole head MEG) while participants were looking at faces differing in familiarity (famous vs. unknown) and orientation (upright vs. inverted). The underlying neural sources were estimated by means of the least square minimum-norm-estimation (L2-MNE) approach. Principal Findings The behavioural data corroborate earlier findings on impaired configural processing in congenital prosopagnosia. For the M170, the overall results replicated earlier findings, with larger occipito-temporal brain responses to inverted than upright faces, and more right- than left-hemispheric activity. Compared to controls, participants with congenital prosopagnosia displayed a general decrease in brain activity, primarily over left occipitotemporal areas. This attenuation did not interact with familiarity or orientation. Conclusions The study substantiates the finding of an early involvement of the left hemisphere in symptoms of prosopagnosia. This might be related to an efficient and overused featural processing strategy

  15. Early left-hemispheric dysfunction of face processing in congenital prosopagnosia: an MEG study.

    Directory of Open Access Journals (Sweden)

    Christian Dobel

    Full Text Available BACKGROUND: Congenital prosopagnosia is a severe face perception impairment which is not acquired by a brain lesion and is presumably present from birth. It manifests mostly by an inability to recognise familiar persons. Electrophysiological research has demonstrated the relevance to face processing of a negative deflection peaking around 170 ms, labelled accordingly as N170 in the electroencephalogram (EEG and M170 in magnetoencephalography (MEG. The M170 was shown to be sensitive to the inversion of faces and to familiarity--two factors that are assumed to be crucial for congenital prosopagnosia. In order to locate the cognitive dysfunction and its neural correlates, we investigated the time course of neural activity in response to these manipulations. METHODOLOGY: Seven individuals with congenital prosopagnosia and seven matched controls participated in the experiment. To explore brain activity with high accuracy in time, we recorded evoked magnetic fields (275 channel whole head MEG while participants were looking at faces differing in familiarity (famous vs. unknown and orientation (upright vs. inverted. The underlying neural sources were estimated by means of the least square minimum-norm-estimation (L2-MNE approach. PRINCIPAL FINDINGS: The behavioural data corroborate earlier findings on impaired configural processing in congenital prosopagnosia. For the M170, the overall results replicated earlier findings, with larger occipito-temporal brain responses to inverted than upright faces, and more right- than left-hemispheric activity. Compared to controls, participants with congenital prosopagnosia displayed a general decrease in brain activity, primarily over left occipitotemporal areas. This attenuation did not interact with familiarity or orientation. CONCLUSIONS: The study substantiates the finding of an early involvement of the left hemisphere in symptoms of prosopagnosia. This might be related to an efficient and overused featural

  16. Diverticular and Aneurysmal Structures of the Left Ventricle in Adults

    Science.gov (United States)

    Makkuni, Premraj; Kotler, Morris N.; Figueredo, Vincent M.

    2010-01-01

    Left ventricular outpouchings are increasingly detected on cardiovascular imaging. Herein, we describe the case of a 45-year-old man who underwent noncardiac preoperative imaging and was found to have an asymptomatic left ventricular outpouching. The patient underwent successful surgical repair of the structure. When left ventricular outpouchings are detected, the main differential diagnoses are pseudoaneurysm, aneurysm, and diverticulum. The outcomes for these conditions differ substantially, and accurate diagnosis can be crucial in making clinical decisions. We review the relevant medical literature, outline the natural history of these left ventricular abnormalities, and discuss options in regard to their management. PMID:21224951

  17. Temporal Order Processing of Syllables in the Left Parietal Lobe

    National Research Council Canada - National Science Library

    Moser, Dana; Baker, Julie M; Sanchez, Carmen E; Rorden, Chris; Fridriksson, Julius

    2009-01-01

    Speech processing requires the temporal parsing of syllable order. Individuals suffering from posterior left hemisphere brain injury often exhibit temporal processing deficits as well as language deficits...

  18. Fragmented QRS and Left Ventricular Geometry in Hypertensive Patients

    Directory of Open Access Journals (Sweden)

    Lütfü Bekar

    2013-08-01

    Full Text Available Introduction: Fragmented QRS is a depolarization abnormality detected with routin ECG recording. It is related with conduction defect which occurs after myocardial fibrosis. In the left ventricular hypertrophy, an excessive amount of collagen accumulates in the interstitium when the myocytes became hypertrophied, resulting in myocardial fibrosis. In this study, we aimed to investigate the relationship of fragmented QRS which was detected on ECG recordings of the hypertensive patients with the left ventricular geometry.Patients and Methods: Essential hypertension patients referred to our hospital on outpatient bases were included in the study. 12-lead resting ECG was taken in all the patients. Left ventricular geometry defined using left ventricular mass index and relative wall thickness with transthorasic echocardiography.Results: Sixy seven patients with fragmented QRS and 63 patients without fragmented QRS included the study. We found that patients in the group with fragmented QRS detected have a wider mean left atrium diameter, greater left ventricular mass and left ventricular mass index compared with the group without fragmented QRS. Concentric and eccentric hypertrophy were more common in fragmented QRS group, while normal geometry and concentric remodelling have greater rates in the normal group.Conclusion: Left ventricular hypertrophy is observed more frequently in the patients with fragmented QRS than without fragmented QRS. This may be associated with the increased myocardial fibrosis in the left ventricular hypertrophy. Existence of fragmented QRS can be used for risk stratification in the hypertensive patients.

  19. What’s on the left?

    Directory of Open Access Journals (Sweden)

    Paul Isambert

    2011-07-01

    Full Text Available Discourse structure is investigated from the point of view of topic shifts. The paper focuses on the French adverb autrement, an important tool in such operations. It requires an antecedent, the topic to be shifted, which it generally finds among salient elements such as topicalized noun phrases or frames. However, since there might be several such elements in the left context, other devices are used to ensure that interlocutors clearly understand which topic is being shifted, i.e. what the antecedent of autrement is. These devices are mostly: stating the new topic, which is similar in many respects (syntax, semantics to the previous one; the repetition of an overarching topic is also an important way to clarify discourse structure. In cases where such markers are absent, it is hypothesized that topics exist at least covertly. On the whole, discourse structure, and especially the left context, must be highly organized if autrement is to work properly. Thus, the study of autrement offers an interesting perspective on discourse structure as a whole, including the Right Frontier constraint: not only does autrement find its antecedent on the Right Frontier, it also shapes it by closing topics and modifying the availability of discourse referents.Cet article étudie la structure du discours du point de vue des changements de topiques, et plus précisément en se concentrant sur l’adverbe autrement et son rôle central dans une telle opération. Ce marqueur nécessite un antécédent, le topique qu’il ferme, qu’il trouve généralement parmi les éléments saillants du discours tels que les groupes nominaux topicalisés et les cadratifs. Cependant, comme il peut y avoir plusieurs éléments de cette sorte dans le contexte gauche, d’autres procédés sont aussi employés pour s’assurer que les interlocuteurs comprennent clairement quel topique est fermé, c’est-à-dire quel élément est l’antécédent d’autrement. Ces procédés sont

  20. Intra-coronary administration of tacrolimus markedly attenuates infarct size and preserves heart function in porcine myocardial infarction

    Directory of Open Access Journals (Sweden)

    Chua Sarah

    2012-06-01

    Full Text Available Abstract Background We test the hypothesis that intra-coronary tacrolimus administration can limit infarct size and preserve left ventricular ejection fraction (LVEF after acute myocardial infarction (AMI through ligating left anterior descending coronary artery (LAD in mini-pigs. Methods Twelve male mini-pigs were randomized into AMI-saline (MI-only group and AMI-tacrolimus (MI-Tac group that received intra-coronary saline (3.0 mL and tacrolimus (0.5 mg in 2.5 mL saline injection, respectively, beyond site of ligation 30 minutes after LAD occlusion. Results Larger infarct area was noted in MI-only group (p  Conclusion Intra-coronary administration of tacrolimus significantly attenuated infarct size and preserved LV function.

  1. Gas sensor with attenuated drift characteristic

    Science.gov (United States)

    Chen, Ing-Shin [Danbury, CT; Chen, Philip S. H. [Bethel, CT; Neuner, Jeffrey W [Bethel, CT; Welch, James [Fairfield, CT; Hendrix, Bryan [Danbury, CT; Dimeo, Jr., Frank [Danbury, CT

    2008-05-13

    A sensor with an attenuated drift characteristic, including a layer structure in which a sensing layer has a layer of diffusional barrier material on at least one of its faces. The sensor may for example be constituted as a hydrogen gas sensor including a palladium/yttrium layer structure formed on a micro-hotplate base, with a chromium barrier layer between the yttrium layer and the micro-hotplate, and with a tantalum barrier layer between the yttrium layer and an overlying palladium protective layer. The gas sensor is useful for detection of a target gas in environments susceptible to generation or incursion of such gas, and achieves substantial (e.g., >90%) reduction of signal drift from the gas sensor in extended operation, relative to a corresponding gas sensor lacking the diffusional barrier structure of the invention

  2. Controlled Attenuation Parameter And Alcoholic Hepatic Steatosis

    DEFF Research Database (Denmark)

    Thiele, Maja; Rausch, Vanessa; Fluhr, Gabriele

    2018-01-01

    ≥S2 = 0.78; 0.72-0.83) and severe steatosis with good accuracy (AUC S3 = 0.82; 0.75-0.88). CAP was superior to bright liver echo pattern by regular ultrasound. CAP above 290 dB/m ruled in any steatosis with 88% specificity and 92% positive predictive value, while CAP below 220 dB/m ruled out....... LAY SUMMARY: Controlled attenuation parameter (CAP) is a new ultrasound based technique for measuring fat content in the liver, but has never been tested for fatty liver due to alcohol. We here examine 562 patients in a multicenter setting. We show that CAP highly correlates with liver fat...... detoxification on CAP. METHODS: Cross-sectional, biopsy-controlled, diagnostic study in four European liver centers. Consecutive alcohol-overusing patients underwent concomitant CAP, regular ultrasound and liver biopsy. In addition, we measured CAP before and after admission for detoxification in a separate...

  3. Release and attenuation of fluorocarbons in landfills

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Scheutz, Charlotte

    2003-01-01

    Several halocarbons with very high global warming and ozone depleting potentials have been used as blowing agent for insulation foam in refrigerators and freezers. Many appliances are shredded after the end of their useful life. Release experiments carried out in the laboratory on insulation foam...... blown with CFC-11, HCFC-141b, HFC- 134a, and HFC-245fa revealed that most of the blowing agent is not released to the atmosphere during a six-week period following the shredding process. The fraction which is released in the six-week period is highly dependent on how fine the foam is shredded....... The residual blowing agent remaining after the six-week period may be very slowly released if the integrity of the foam particles with respect to diffusional properties is kept after disposal of the foam waste in landfills. Laboratory experiments simulating attenuation processes in the landfilled waste...

  4. Glutathione attenuates uranyl toxicity in Lactococcus lactis

    Energy Technology Data Exchange (ETDEWEB)

    Fahmy, Karim; Oertel, Jana [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biophysics; Obeid, M. [Technische Univ. Dresden (Germany); Solioz, M. [Bern Univ. (Switzerland)

    2017-06-01

    We investigated the role of intracellular glutathione (GSH), which in a large number of taxa plays a role in the protection against the toxicity of heavy metals. Anaerobically grown Lactococcus lactis containing an inducible GSH synthesis pathway was used as a model organism allowing the study of GSH-dependent uranyl detoxification without interference from additional reactive oxygen species. Microcalorimetric measurements of the metabolic heat showed that intracellular GSH attenuates the toxicity of uranium at a concentration in the range of 10-150 μM. Isothermal titration calorimetry revealed the endothermic binding of U(VI) to the carboxyl group(s) of GSH. The data indicate that the primary detoxifying mechanism is the intracellular sequestration of carboxyl-coordinated U(VI) into an insoluble complex with GSH.

  5. LIVE ATTENUATED VACCINES FOR THE IMMUNOPROPHYLAXIS

    Directory of Open Access Journals (Sweden)

    O. A. Shamsutdinova

    2017-01-01

    Full Text Available The review focuses on the history of the production of live antiviral vaccines and their use for the prevention of infectious diseases. It was noted that before the beginning of the 20th century, only three live vaccines were developed and put into practice — against smallpox, rabies, plague. The discovery of D. Enders, T.H. Weller and F.Ch. Robins of the ability of the polio virus, and then of a number of other viruses, to reproduce in vitro in cell cultures of various types, greatly expanded the studies on the production of attenuated strains of viruses for live vaccines. The historical stages of obtaining and introducing live vaccines for the prevention of smallpox, poliomyelitis, measles, rubella, and mumps are highlighted. Arguments in favor of the use of associated vaccine preparations for the prevention of viral infections are presented. Various variants of the strategy and tactics of using live vaccines, which are used for specific prevention of viral infections in different countries, are described. The review provides information on technological methods for obtaining antiviral vaccines. The publications testifying to the development of specific reactions in immunized vaccine strains of measles, mumps, poliomyelitis and rubella viruses, such as aseptic meningitis (vaccine strains of mumps virus, acute arthritis (vaccine rubella virus strains, temperature reactions, rash (vaccine strains of the virus Measles, vaccine-associated paralytic poliomyelitis (VAPP vaccine vaccine poliovirus. It is particularly noted that the long experience of vaccine prevention both in Russia and abroad convincingly shows that the risk of developing post-vaccination complications is incommensurably lower than the risk of causing harm to health from the corresponding infections. It is concluded that despite introduction of new third and fourth generation vaccines into practice, live attenuated vaccines do not lose their significance and are used in vaccine

  6. Targeting Phospholipase D4 Attenuates Kidney Fibrosis.

    Science.gov (United States)

    Trivedi, Priyanka; Kumar, Ramya K; Iyer, Ashwin; Boswell, Sarah; Gerarduzzi, Casimiro; Dadhania, Vivekkumar P; Herbert, Zach; Joshi, Nikita; Luyendyk, James P; Humphreys, Benjamin D; Vaidya, Vishal S

    2017-12-01

    Phospholipase D4 (PLD4), a single-pass transmembrane glycoprotein, is among the most highly upregulated genes in murine kidneys subjected to chronic progressive fibrosis, but the function of PLD4 in this process is unknown. Here, we found PLD4 to be overexpressed in the proximal and distal tubular epithelial cells of murine and human kidneys after fibrosis. Genetic silencing of PLD4, either globally or conditionally in proximal tubular epithelial cells, protected mice from the development of fibrosis. Mechanistically, global knockout of PLD4 modulated innate and adaptive immune responses and attenuated the upregulation of the TGF-β signaling pathway and α1-antitrypsin protein (a serine protease inhibitor) expression and downregulation of neutrophil elastase (NE) expression induced by obstructive injury. In vitro, treatment with NE attenuated TGF-β-induced accumulation of fibrotic markers. Furthermore, therapeutic targeting of PLD4 using specific siRNA protected mice from folic acid-induced kidney fibrosis and inhibited the increase in TGF-β signaling, decrease in NE expression, and upregulation of mitogen-activated protein kinase signaling. Immunoprecipitation/mass spectrometry and coimmunoprecipitation experiments confirmed that PLD4 binds three proteins that interact with neurotrophic receptor tyrosine kinase 1, a receptor also known as TrkA that upregulates mitogen-activated protein kinase. PLD4 inhibition also prevented the folic acid-induced upregulation of this receptor in mouse kidneys. These results suggest inhibition of PLD4 as a novel therapeutic strategy to activate protease-mediated degradation of extracellular matrix and reverse fibrosis. Copyright © 2017 by the American Society of Nephrology.

  7. Engineering a Light-Attenuating Artificial Iris

    Science.gov (United States)

    Shareef, Farah J.; Sun, Shan; Kotecha, Mrignayani; Kassem, Iris; Azar, Dimitri; Cho, Michael

    2016-01-01

    Purpose Discomfort from light exposure leads to photophobia, glare, and poor vision in patients with congenital or trauma-induced iris damage. Commercial artificial iris lenses are static in nature to provide aesthetics without restoring the natural iris's dynamic response to light. A new photo-responsive artificial iris was therefore developed using a photochromic material with self-adaptive light transmission properties and encased in a transparent biocompatible polymer matrix. Methods The implantable artificial iris was designed and engineered using Photopia, a class of photo-responsive materials (termed naphthopyrans) embedded in polyethylene. Photopia was reshaped into annular disks that were spin-coated with polydimethylsiloxane (PDMS) to form our artificial iris lens of controlled thickness. Results Activated by UV and blue light in approximately 5 seconds with complete reversal in less than 1 minute, the artificial iris demonstrates graded attenuation of up to 40% of visible and 60% of UV light. There optical characteristics are suitable to reversibly regulate the incident light intensity. In vitro cell culture experiments showed up to 60% cell death within 10 days of exposure to Photopia, but no significant cell death observed when cultured with the artificial iris with protective encapsulation. Nuclear magnetic resonance spectroscopy confirmed these results as there was no apparent leakage of potentially toxic photochromic material from the ophthalmic device. Conclusions Our artificial iris lens mimics the functionality of the natural iris by attenuating light intensity entering the eye with its rapid reversible change in opacity and thus potentially providing an improved treatment option for patients with iris damage. PMID:27116547

  8. Unruptured aneurysm of the left sinus of Valsalva compressing the left main coronary artery: successful percutaneous treatment.

    Science.gov (United States)

    Hausinger, P; Sasi, V; Volford, G; Bitay, M; Bogáts, G; Thury, A; Palkó, A; Forster, T; Nemes, A

    2014-09-01

    Aneurysm of the left sinus of Valsalva is an extremely rare entity. It may be asymptomatic and incidentally discovered, or may be symptomatic and manifest acutely with compression of adjacent cardiac structures. Encasement of the left main coronary artery by such an aneurysm is a recognized but infrequent complication that can lead to severe coronary insufficiency. Surgical decompression of the left main coronary artery is the standard treatment for such conditions. We describe a patient presenting with extrinsic compression of the left main coronary artery by a large unruptured aneurysm of the left sinus of Valsalva occurring 4 months after unsuccessful surgical repair. Since reoperation was considered high-risk for the patient, successful fractional flow reserve- and intravascular ultrasound-guided percutaneous treatment of the left main coronary artery was performed with implantation of one bare-metal stent.

  9. The left atrium, atrial fibrillation, and the risk of stroke in hypertensive patients with left ventricular hypertrophy

    DEFF Research Database (Denmark)

    Wachtell, K.; Devereux, R.B.; Lyle, P.A.

    2008-01-01

    was superior to atenolol-based treatment for reducing new-onset AF and complications, especially stroke, associated with new-onset or pre-existing AF. Potential mechanisms of AF prevention by angiotensin receptor blockade supported by LIFE results include greater reduction in left atrial size and LV...... hypertrophy. Differential effects of antihypertensive treatment on the left atrium and left ventricle may help prevent AF and reduce risk of stroke associated with hypertensive heart disease Udgivelsesdato: 2008/12...

  10. Left atrial strain: a new parameter for assessment of left ventricular filling pressure.

    Science.gov (United States)

    Cameli, Matteo; Mandoli, Giulia Elena; Loiacono, Ferdinando; Dini, Frank Lloyd; Henein, Michael; Mondillo, Sergio

    2016-01-01

    In order to obtain accurate diagnosis, treatment and prognostication in many cardiac conditions, there is a need for assessment of left ventricular (LV) filling pressure. While systole depends on ejection function of LV, diastole and its disturbances influence filling function and pressures. The commonest condition that represents the latter is heart failure with preserved ejection fraction in which LV ejection is maintained, but diastole is disturbed and hence filling pressures are raised. Significant diastolic dysfunction results in raised LV end-diastolic pressure, mean left atrial (LA) pressure and pulmonary capillary wedge pressure, all referred to as LV filling pressures. Left and right heart catheterization has traditionally been used as the gold standard investigation for assessing these pressures. More recently, Doppler echocardiography has taken over such application because of its noninvasive nature and for being patient friendly. A number of indices are used to achieve accurate assessment of filling pressures including: LV pulsed-wave filling velocities (E/A ratio, E wave deceleration time), pulmonary venous flow (S wave and D wave), tissue Doppler imaging (E' wave and E/E' ratio) and LA volume index. LA longitudinal strain derived from speckle tracking echocardiography (STE) is also sensitive in estimating intracavitary pressures. It is angle-independent, thus overcomes Doppler limitations and provides highly reproducible measures of LA deformation. This review examines the application of various Doppler echocardiographic techniques in assessing LV filling pressures, in particular the emerging role of STE in assessing LA pressures in various conditions, e.g., HF, arterial hypertension and atrial fibrillation.

  11. Left subclavian artery revascularization as part of thoracic stent grafting.

    Science.gov (United States)

    Saouti, Nabil; Hindori, Vikash; Morshuis, William J; Heijmen, Robin H

    2015-01-01

    Intentional covering of the left subclavian artery (LSA) as part of thoracic endovascular aortic repair (TEVAR) can cause (posterior) strokes or left arm malperfusion. LSA revascularization can be done as prophylaxis against, or as treatment of, these complications. We report our experience with the surgical technique, indications and the results of LSA revascularization. Between 2000 and 2013, 51 patients of 444 patients who were treated by TEVAR, had LSA revascularization. All elective patients had a preoperative work-up with magnetic resonance angiography to evaluate the circle of Willis. In all, surgical access was through a left supraclavicular incision only. The majority (90%) had prophylactic LSA revascularization because of incomplete circle of Willis and or dominant left vertebral artery (LVA) (n=29), patent left internal mammary artery (n=1), prevention spinal cord ischaemia (SCI) (n=2), prevention left arm ischaemia due to small LVA (n=2) and LVA origin in arch (n=1). Fourteen percent had secondary revascularization, either immediate because of malperfusion of the left arm (n=2) or late after TEVAR because of persisting left arm claudication (n=5). In 12 patients, the following early complications were observed: re-exploration for bleeding, n=1; left recurrent nerve paralysis, n=2; left phrenic nerve paralysis, n=1; left sympathetic chain neuropraxia, resulting in Horner's syndrome, n=3; Chyle duct lesions, resulting in persistent Chyle leakage, n=3. Neither strokes nor SCI was observed. One patient experienced occlusion of the bypass at 6 months. The present study shows that the procedure of LSA revascularization as part of TEVAR is safe with low morbidity consisting of mainly (transient) nerve palsy. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  12. Recurrent left atrial and left ventricular thrombosis due to heparin-induced thrombocytopenia: case report and short review.

    Science.gov (United States)

    Kuhl, Thomas; Wendt, Stefanie; Langebartels, Georg; Kröner, Axel; Wahlers, Thorsten

    2013-09-01

    The combination of heparin-induced thrombocytopenia (HIT) II, left ventricular failure with extracorporeal membrane oxygenation (ECMO) therapy, and recurrent left ventricular thrombosis is rare and predicts a poor outcome. In this case, HIT II occurred after an ischemic cardiogenic shock. We initiated ECMO and intra-aortic balloon pump therapy during coronary artery bypass grafting and ventricular thrombectomy. Despite continued therapeutic therapy with heparin and later argatroban, the patient developed solid and recurrent thrombotic masses in the left atrium and left ventricle. Georg Thieme Verlag KG Stuttgart · New York.

  13. The thermal effect on the left-handedness of the mesoscopic composite right-Left handed transmission line

    Science.gov (United States)

    Wei, Xiao-Jing; Zhao, Shun-Cai; Guo, Hong-Wei

    2017-10-01

    Starting from the quantum fluctuation of current in the mesoscopic composite right-left handed transmission line (CRLH-TL) in the thermal Fock state, we investigate the left-handedness dependent of the frequencies, intensity and quantum fluctuations of the current field in the CRLH-TL under different thermal environment. The results show that the intensity and quantum fluctuations of current field in lower frequency bands affect the left-handedness distinctly under different thermal environment. The thermal effect on the left-handedness in the mesoscopic CRLH-TL deserves further experimental investigation in its miniaturization application.

  14. Osteopathic treatment in a patient with left-ventricular assist device with left brachialgia: a case report.

    Science.gov (United States)

    Bordoni, Bruno; Marelli, Fabiola; Morabito, Bruno; Sacconi, Beatrice

    2017-01-01

    This study deals with an osteopathic approach used for a patient with left-ventricular assist device (L-VAD) affected by left brachialgia. Clinical examination revealed the presence of thoracic outlet syndrome and pectoralis minor syndrome, with compression of the left proximal ulnar nerve, related to the surgical sternotomy performed. The osteopathic techniques used can be classified as indirect and direct, addressed to the pectoralis minor and the first left rib, respectively. To our knowledge, this is the first text in literature with an osteopathic treatment in a patient with L-VAD.

  15. Bronchial compression by an enlarged left atrium in infants; a cause of hypovascularity of the left lung

    Energy Technology Data Exchange (ETDEWEB)

    Corr, L.; Hallidie-Smith, K.A.; McCarthy, P.A.; Lavender, J.P.

    1988-09-01

    In three infants seen recently at our institution we noted signs of compression of the left main bronchus associated with enlarged left atria. None of our cases demonstrated the more usual signs of hyperinflation which are a hyperlucent lung field, depressed hemidiaphragm and mediastinal shift away from the affected side. In addition, hypoperfusion of the left lung was noted in each case. We believe that bronchial compression due to an enlarged left atrium, with consequent hypoxic vasoconstriction is a clinically significant entity, which is not well described and may be unappreciated in infants in whom the typical signs of hyperinflation are absent.

  16. A study of ultrasonic velocity and attenuation on polycrystalline Ni ...

    Indian Academy of Sciences (India)

    Unknown

    (longitudinal and transverse) and attenuation has been qualitatively explained with the help of the temperature variation of the magneto-crystalline anisotropy constant. Keywords. Ferrites; magnetic properties; ultrasonic velocity; attenuation; domain walls. 1. Introduction. There is an abundant literature on the propagation of.

  17. Simulation on the shock attenuation behavior of coupled RHA and ...

    African Journals Online (AJOL)

    Based from the results, coupled RHA and sandwich composite structure configuration exhibit highest attenuation capability of 61.3% respectively. The study can be used as reference tool for the application related to automotive, naval and aeronautical structures, oil and gas industry. Keywords: shock attenuation; composite; ...

  18. Periportal low-attenuation: a CT sign of lymphatic obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hoon; Kim, Chong Soo; Yang, Doo Hyun; Lee, Sang Yong; Lee, Young Whan; Chung, Gyung Ho; Han, Young Min; Sohn, Myung Hee; Choi, Ki Chul [Chonbuk National University College of Medicine, Jeonju (Korea, Republic of)

    1995-07-15

    Periportal low attenuation, defined as a low attenuation rim around the portal vein and its branches which is seen on contrast material-enhanced CT scans, has been described in a variety of conditions. We tried to document that lymphatic obstruction is one of the major cause of periportal low attenuation. We retrospectively analyzed 57 cases of periportal low attenuation of abdominal CT scans and also reviewed the surgical records in 32 cases. Lymph node enlargement in the hepatoduodenal ligament which is a main lymphatic channel from the liver were analyzed the calculated the ratio of the transeverse diameter between the inferior vena cava and the aorta at the level of right adrenal gland. After complete surgical interruption of the lymphatic drainage from the liver in a dog, follow up CT scans were obtained and correlated with pathologic findings. Fifty patients (88%) had underlying disease which could cause impairment of lymphatic drainage. Periportal low attenuation was identified in several clinical conditions, including surgical lymph node dissection, lymphadenopathy in the hepatoduodenal ligament, blunt trauma. In animal model, CT scan showed prominent periportal low attenuation at 5 days after surgery. Histologic examination revealed numerous dilated lymphatic vessels and a marked lymphedema in the connective tissues surrounding the portal vein and its major branches. One of the major cause of periportal low attenuation was impaired lymphatic drainage and periportal low attenuation corresponding to the numerous dilated lymphatic vessels and a marked lymphedema in the connective tissues surrounding the portal vein and its major branches.

  19. Determination of gamma ray attenuation coefficients of Al–4% Cu ...

    Indian Academy of Sciences (India)

    Gamma ray attenuation coefficients of metal matrix composites have been investigated. For this purpose, the linear attenuation coefficients of composites containing boron carbide (B4C) at different rates have been measured using a gamma spectrometer that contains a NaI(Tl) detector and MCA at 662, 1173 and 1332 keV, ...

  20. Determination of gamma ray attenuation coefficients of Al–4% Cu ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. Gamma ray attenuation coefficients of metal matrix composites have been investigated. For this purpose, the linear attenuation coefficients of composites containing boron carbide (B4C) at different rates have been measured using a gamma spectrometer that contains a NaI(Tl) detector and MCA at 662, 1173 and.

  1. Spatial and seasonal variation in wave attenuation over Zostera noltii

    Science.gov (United States)

    Paul, M.; Amos, C. L.

    2011-08-01

    Wave attenuation is a recognized function of sea grass ecosystems which is believed to depend on plant characteristics. This paper presents field data on wave attenuance collected over a 13 month period in a Zostera noltii meadow. The meadow showed a strong seasonality with high shoot densities in summer (approximately 4,600 shoots/m2) and low densities in winter (approximately 600 shoots/m2). Wave heights and flow velocities were measured along a transect at regular intervals during which the site was exposed to wind waves and boat wakes that differ in wave period and steepness. This difference was used to investigate whether wave attenuation by sea grass changes with hydrodynamic conditions. A seasonal change in wave attenuation was observed from the data. Results suggest that a minimum shoot density is necessary to initiate wave attenuation by sea grass. Additionally, a dependence of wave attenuation on hydrodynamics was found. Results suggest that the threshold shoot density varies with wave period and a change in energy dissipation toward the shore was observed once this threshold was exceeded. An attempt was made to quantify the bed roughness of the meadow; the applicability of this roughness value in swaying vegetation is discussed. Finally, the drag coefficient for the meadow was computed: A relationship between wave attenuance and vegetation Reynolds number was found which allows comparing the wave attenuating effect of Zostera noltii to other plant species.

  2. Light attenuation characteristics of glacially-fed lakes

    Science.gov (United States)

    Rose, Kevin C.; Hamilton, David P.; Williamson, Craig E.; McBride, Chris G.; Fischer, Janet M.; Olson, Mark H.; Saros, Jasmine E.; Allan, Mathew G.; Cabrol, Nathalie

    2014-07-01

    Transparency is a fundamental characteristic of aquatic ecosystems and is highly responsive to changes in climate and land use. The transparency of glacially-fed lakes may be a particularly sensitive sentinel characteristic of these changes. However, little is known about the relative contributions of glacial flour versus other factors affecting light attenuation in these lakes. We sampled 18 glacially-fed lakes in Chile, New Zealand, and the U.S. and Canadian Rocky Mountains to characterize how dissolved absorption, algal biomass (approximated by chlorophyll a), water, and glacial flour contributed to attenuation of ultraviolet radiation (UVR) and photosynthetically active radiation (PAR, 400-700 nm). Variation in attenuation across lakes was related to turbidity, which we used as a proxy for the concentration of glacial flour. Turbidity-specific diffuse attenuation coefficients increased with decreasing wavelength and distance from glaciers. Regional differences in turbidity-specific diffuse attenuation coefficients were observed in short UVR wavelengths (305 and 320 nm) but not at longer UVR wavelengths (380 nm) or PAR. Dissolved absorption coefficients, which are closely correlated with diffuse attenuation coefficients in most non-glacially-fed lakes, represented only about one quarter of diffuse attenuation coefficients in study lakes here, whereas glacial flour contributed about two thirds across UVR and PAR. Understanding the optical characteristics of substances that regulate light attenuation in glacially-fed lakes will help elucidate the signals that these systems provide of broader environmental changes and forecast the effects of climate change on these aquatic ecosystems.

  3. Wave attenuation in mangroves; a quantitative approach to field observations

    NARCIS (Netherlands)

    Horstman, Erik; Dohmen-Janssen, Catarine M.; Narra, P.M.F.; van den Berg, N.J.F.; Siemerink, M.; Hulscher, Suzanne J.M.H.

    2014-01-01

    Coastal mangroves, dwelling at the interface between land and sea, provide an important contribution to reducing risk from coastal hazards by attenuating incident waves and by trapping and stabilizing sediments. This paper focusses on relations between vegetation densities, wave attenuation rates,

  4. Ultrasonic velocity and attenuation anisotropy of shales, Whitby, United Kingdom

    NARCIS (Netherlands)

    Zhubayev, Alimzhan; Houben, M.E.|info:eu-repo/dai/nl/370588843; Smeulders, David; Barnhoorn, A.|info:eu-repo/dai/nl/304843636

    We have conducted ultrasonic experiments, between 0.3 and 1 MHz, to measure velocity and attenuation (Q−1) anisotropy of P- and S-waves in dry Whitby Mudstone samples as a function of stress. We found the degree of anisotropy to be as large as 70% for velocity and attenuation. The sensitivity of

  5. Ultrasonic velocity and attenuation anisotropy of shales, Whitby, United Kingdom

    NARCIS (Netherlands)

    Zhubayev, A.; Houben, M.E.; Smeulders, D.M.J.; Barnhoorn, A.

    2015-01-01

    We have conducted ultrasonic experiments, between 0.3 and 1 MHz, to measure velocity and attenuation (Q?1) anisotropy of P- and S-waves in dry Whitby Mudstone samples as a function of stress. We found the degree of anisotropy to be as large as 70% for velocity and attenuation. The sensitivity of

  6. Ultrasound attenuation dependence on air compression or expansion processes

    NARCIS (Netherlands)

    Jakevicius, L.; Demcenko, A.; Mardosaite, R.

    2010-01-01

    In this work variation of ultrasonic attenuation coefficient is analyzed in terms of air compression or expansion processes. In closed spaces changing air volume, the ultrasound attenuation coefficient depends on thermodynamic processes which occur during the air volume change. Two limiting cases

  7. Attenuation of Cardiovascular response by ß-blocker esmolol during ...

    African Journals Online (AJOL)

    Cardiovascular responses to laryngoscopy and intubation have long been recognized and various efforts have been made to attenuate this response. The aim of this study was to evaluate the efficacy and safety of ß-blocker esmolol in attenuating cardiovascular response to laryngoscopy and tracheal intubation in the ...

  8. Attenuated radon transform: theory and application in medicine and biology

    Energy Technology Data Exchange (ETDEWEB)

    Gullberg, G.T.

    1979-06-01

    A detailed analysis is given of the properties of the attenuated Radon transform and of how increases in photon attenuation influence the numerical accuracy and computation efficiency of iterative and convolution algorithms used to determine its inversion. The practical applications for this work involve quantitative assessment of the distribution of injected radiopharmaceuticals and radionuclides in man and animals for basic physiological and biochemical studies as well as clinical studies in nuclear medicine. A mathematical structure is developed using function theory and the theory of linear operators on Hilbert spaces which lends itself to better understanding the spectral properties of the attenuated Radon transform. The continuous attenuated Radon transform reduces to a matrix operator for discrete angular and lateral sampling, and the reconstruction problem reduces to a system of linear equations. For the situation of variable attenuation coefficient frequently found in nuclear medicine applications of imaging the heart and chest, the procedure developed in this thesis involves iterative techniques of performing the generalized inverse. For constant attenuation coefficient less than 0.15 cm/sup -1/, convolution methods can reliably reconstruct a 30 cm object with 0.5 cm resolution. However, for high attenuation coefficients or for the situation where there is variable attenuation such as reconstruction of distribution of isotopes in the heart, iterative techniques developed in this thesis give the best results. (ERB)

  9. Doxycycline Attenuated Pulmonary Fibrosis Induced by Bleomycin in Mice

    OpenAIRE

    Fujita, Masaki; Ye, Qing; Ouchi, Hiroshi; Harada, Eiji; Inoshima, Ichiro; Kuwano, Kazuyoshi; Nakanishi, Yoichi

    2006-01-01

    The administration of doxycycline prior to bleomycin in mice attenuated pulmonary fibrosis. Bronchoalveolar neutrophil influx and gelatinase activity, but not caseinolytic activity, were attenuated by doxycycline. Established fibrosis was not affected by doxycycline. Thus, doxycycline might be useful for slowing down pulmonary fibrosis by biological activity other than antibacterial activity.

  10. Slant-Path Rain Attenuation Statistics over Nigeria | Adefolalu ...

    African Journals Online (AJOL)

    The study shows that attenuation is higher for western, southern, or lower altitude stations. Also attenuation of horizontally polarized waves exceed that of vertical polarization by increasing margins at higher frequencies, which makes vertical polarization more preferable at higher microwave frequencies. Thus, the emerging ...

  11. Heterogeneity of left ventricular wall thickening mechanisms.

    Science.gov (United States)

    Cheng, Allen; Nguyen, Tom C; Malinowski, Marcin; Daughters, George T; Miller, D Craig; Ingels, Neil B

    2008-08-12

    Myocardial fibers are grouped into lamina (or sheets) 3 to 4 cells thick. Fiber shortening produces systolic left ventricular (LV) wall thickening primarily by laminar extension, thickening, and shear, but the regional variability and transmural distribution of these 3 mechanisms are incompletely understood. Nine sheep had transmural radiopaque markers inserted into the anterior basal and lateral equatorial LV. Four-dimensional marker dynamics were studied with biplane videofluoroscopy to measure circumferential, longitudinal, and radial systolic strains in the epicardium, midwall, and endocardium. Fiber and sheet angles from quantitative histology allowed transformation of these strains into transmural contributions of sheet extension, thickening, and shear to systolic wall thickening. At all depths, systolic wall thickening in the anterior basal region was 1.6 to 1.9 times that in the lateral equatorial region. Interestingly, however, systolic fiber shortening was identical at each transmural depth in these regions. Endocardial anterior basal sheet thickening was >2 times greater than in the lateral equatorial region (epicardium, 0.16+/-0.15 versus 0.03+/-0.06; endocardium, 0.45+/-0.40 versus 0.17+/-0.09). Midwall sheet extension was >2 times that in the lateral wall (0.22+/-0.12 versus 0.09+/-0.06). Epicardial and midwall sheet shears in the anterior wall were approximately 2 times higher than in the lateral wall (epicardium, 0.14+/-0.07 versus 0.05+/-0.03; midwall, 0.21+/-0.12 versus 0.12+/-0.06). These data demonstrate fundamentally different regional contributions of laminar mechanisms for amplifying fiber shortening to systolic wall thickening. Systolic fiber shortening was identical at each transmural depth in both the anterior and lateral LV sites. However, systolic wall thickening of the anterior site was much greater than that of the lateral site. Fiber shortening drives systolic wall thickening, but sheet dynamics and orientations are of great

  12. Inhibition of Uncoupling Protein 2 Attenuates Cardiac Hypertrophy Induced by Transverse Aortic Constriction in Mice

    Directory of Open Access Journals (Sweden)

    Xiao-Bing Ji

    2015-07-01

    Full Text Available Background: Uncoupling protein 2 (UCP2 is critical in regulating energy metabolism. Due to the significant change in energy metabolism of myocardium upon pressure overload, we hypothesize that UCP2 could contribute to the etiology of cardiac hypertrophy. Methods: Adult male C57BL/6J mice were subjected to pressure overload by using transverse aortic constriction (TAC, and then received genipin (a UCP2 selective inhibitor; 25 mg/kg/d, ip or vehicle for three weeks prior to histologic assessment of myocardial hypertrophy. ATP concentration, ROS level, and myocardial apoptosis were also examined. A parallel set of experiments was also conducted in UCP2-/- mice. Results: TAC induced left ventricular hypertrophy, as reflected by increased ventricular weight/thickness and increased size of myocardial cell (vs. sham controls. ATP concentration was decreased; ROS level was increased. Apoptosis and fibrosis markers were increased. TAC increased mitochondrial UCP2 expression in the myocardium at both mRNA and protein levels. Genipin treatment attenuated cardiac hypertrophy and the histologic/biochemical changes described above. Hypertrophy and associated changes induced by TAC in UCP2-/- mice were much less pronounced than in WT mice. Conclusions: Blocking UCP2 expression attenuates cardiac hypertrophy induced by pressure overload.

  13. β2-Adrenoreceptor Agonist Inhalation During Ex Vivo Lung Perfusion Attenuates Lung Injury.

    Science.gov (United States)

    Kondo, Takeshi; Chen, Fengshi; Ohsumi, Akihiro; Hijiya, Kyoko; Motoyama, Hideki; Sowa, Terumasa; Ohata, Keiji; Takahashi, Mamoru; Yamada, Tetsu; Sato, Masaaki; Aoyama, Akihiro; Date, Hiroshi

    2015-08-01

    Attenuation of ischemia reperfusion injury (IRI) is important in lung transplantation. Our group previously reported that β2-adrenoreceptor agonist inhalation during the period before procurement successfully attenuated IRI in donated lungs after cardiac death. We therefore hypothesized that β2-adrenoreceptor agonist inhalation during ex vivo lung perfusion (EVLP) after procurement might also have a protective effect. Cardiac-dead beagles were left at room temperature for 210 minutes, and all lungs were subsequently procured and subjected to EVLP for 240 minutes. The beagles were allocated to 2 groups: the β2 group (receiving an aerosolized β2-adrenoreceptor agonist 20 minutes after initiation of EVLP; n = 7) and the control group (receiving an aerosolized control solvent at the same time point; n = 6). Physiologic data, including lung function, were evaluated during EVLP. The β2 group showed significantly lower peak airway pressure and pulmonary artery pressure than the control group. Dynamic pulmonary compliance was higher, pulmonary vascular resistance (PVR) was lower, and the wet-to-dry lung weight ratio was lower in the β2 group than in the control group. Cyclic adenosine monophosphate (cAMP) and total adenosine nucleotide (TAN) levels in lung tissue after EVLP were higher in the β2 group than in the control group. The β2 group also showed more cystic fibrosis transmembrane conductance regulator (CFTR) gene expression. After procurement, β2-adrenoreceptor agonist inhalation during EVLP attenuates lung injury in a canine model of organ donation after cardiac death. Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  14. Left ventricular structure and function in black normotensive type 2 ...

    African Journals Online (AJOL)

    Patients' age, body weight, duration of DM, LV mass index and left atrial dimension were positive correlates of LVDD while patients' age, weight and left atrial dimension were independent predictors of LVDD. Conclusion: There is high prevalence of alterations in LV structure and function in normotensive type 2 DM; and ...

  15. Left-handedness and neurotic disturbances in adult urban population.

    Science.gov (United States)

    Milenković, Sanja; Brkić, Milica; Belojević, Goran

    2013-01-01

    Controversial results on the relationship between the left-handedness and neurotic disturbances have been obtained in so far investigations. The aim of this study was to investigate the link between the left-handedness and neurotic disturbances in an adult urban population. A cross-sectional study was performed on 1,202 adult residents of the Stari Grad municipality in Belgrade, out of which 401 were males (33.4%) and 801 were females (66.6%). A questionnaire was used as an investigation instrument, with questions concerning age, gender, writing hand and neurotic disturbances: tension, agressiveness, anger, nervousness, weepiness and seclusion. Left-handedness was found in 60 subjects (5%) and it was statistically more frequent in males (7.7%) compared to females (3.6%) (p = 0.003). A decreasing trend of proportion of left-handed males was found in relation to aging. In the age group 18 to 39 years, agressiveness, as a specific neurotic disturbance, was significantly more frequent in left-handed males in comparison to right-handers (p = 0.035). In the age group 40 to 59 years, neurotic disturbances were more common among left-handed males compared to right-handers (p = 0.030).There were no significant diferences in the proportion of neurotic disturbances between the left-handed and the right-handed females. From a public health point of view, left-handed men may be regarded as a relatively vulnerable population category concerning mental health.

  16. Left ventricular systolic function in sickle cell anaemia: an ...

    African Journals Online (AJOL)

    by the report of Balfour and colleagues6 who also ob- served that left ventricular function became increasingly abnormal with age, suggesting that left ventricular func- tion deteriorated with time. It is worth noting that most of the studies reporting abnormal systolic function in sickle cell patients were conducted in children ...

  17. Evaluation of left ventricular volumes measured by magnetic resonance imaging

    DEFF Research Database (Denmark)

    Møgelvang, J; Thomsen, C; Mehlsen, J

    1986-01-01

    Left ventricular end-diastolic and end-systolic volumes were determined in 17 patients with different levels of left ventricular function by magnetic resonance imaging (MRI). A 1.5 Tesla Magnet was used obtaining ECG triggered single and multiple slices. Calculated cardiac outputs were compared...

  18. Transient left atrial dysfunction is a feature of Takotsubo syndrome

    DEFF Research Database (Denmark)

    Stiermaier, Thomas; Graf, Tobias; Möller, Christian

    2017-01-01

    BACKGROUND: Takotsubo syndrome (TTS) is characterized by a transient left and/or right ventricular dysfunction as a consequence of a distinctive pattern of regional wall motion abnormalities. However, a systematic evaluation of the left atrial (LA) function in patients with TTS is lacking. The ai...

  19. [Hemimegalencephaly and pathological left handedness. A case report].

    Science.gov (United States)

    López-Pisón, J; Arana, T; Abenia, P; Ferrer-Lozano, M; Sánchez-Andrés, M; Peña-Segura, J L

    1998-09-01

    Hemimegalencephaly is a disorder of neurone proliferation and migration, associated with excessive growth of all or part of one cerebral hemisphere, and variable degrees of pachygyria, polymicrogyria, neuronal heterotopy and gliosis of white matter. It is considered to be a rare malformation with severe encephalopathy, epilepsy resistant to treatment started early, contralateral hemiparesia and severe retardation of development. However, there may also be milder forms. The syndrome of pathological left handedness is associated with disorders of language, visuo-spatial changes and weakness and hypertrophy of the right limbs, with no family history of left handedness. It occurs in lesions predominantly of the left hemisphere which have occurred in the first six years of life. A 12 year old girl presented with a syndrome of pathological left-handedness and craniofacial asymmetry of the left hemisphere. MR showed the left ventricle and hemisphere to be of increased size and with focal hyperintensity in the white matter, and at the level of the left parietotemporoccipital region there was a thick cortex with little interdigitation of white and grey matter. Minor forms of hemimegalencephaly are probably more frequent than is generally believed. A high index of suspicion is necessary to identify them. They should be considered in cases of left handedness, craniofacial or bodily asymmetry, cutaneous hamartomas, persistent electroencephalographic asymmetry and asymmetry on neuroimaging with an enlarged ventricle and homolateral hemisphere. Study of this may give information which is useful for understanding plasticity and mechanisms of recovery and functional compensation of immature nerve tissue.

  20. Impact of obstructive sleep apnea and snoring on left ventricular ...

    African Journals Online (AJOL)

    Background: Systemic hypertension (HTN) and obstructive sleep apnea (OSA) are individually associated with left ventricular structural and functional adaptations. However, little is known about the impact of OSA on the left ventricle in Africans with HTN. Aim: The aim of this study is to determine the association between ...

  1. Challenges left-handed students face in Kenyan girls' secondary ...

    African Journals Online (AJOL)

    Previous research on left-handedness has mainly taken place in developed countries. This study aimed at investigating the challenges left-handed students faced in secondary school laboratories and how well they coped with the challenges in Kenya. It also sought to find out whether teachers were aware of the challenges ...

  2. Foucault's Flirt? Neoliberalism, the Left and the Welfare State

    DEFF Research Database (Denmark)

    Hansen, Magnus Paulsen

    2015-01-01

    An essay on the review of works interpreting the lectures of Michel Foucault on neoliberalism is presented. It offers a history of neoliberalism as a way to reinvent the left and examines the way Foucault betrayed the left while resisting to be connected with a normative political programme...

  3. Left Sided Trans-thoracic Esophagectomy for Resectable ...

    African Journals Online (AJOL)

    ADMIN

    is placed in a right lateral position and a soft pillow is placed under the right chest to ease access into the inter-costal spaces. In case double lumen intubation was not successful, a single lumen tube advanced into the right main bronchus was found sufficient. A left postero-lateral thoracotomy is performed along the left ...

  4. Left ventricular structure and function in black normotensive type 2 ...

    African Journals Online (AJOL)

    More diabetic patients had left atrial enlargement (LAE) and left bundle branch block (LBBB) than controls (P=0.006 and 0.006 respectively). Abnormalities of ST segment and. Q-wave suggestive of myocardial ischemia were significantly higher (P=0.005) in diabetic cohort than the control. About 17% of diabetics and 5.5%.

  5. Persistent left unilateral mirror writing: A neuropsychological case study.

    Science.gov (United States)

    Angelillo, Valentina G; De Lucia, Natascia; Trojano, Luigi; Grossi, Dario

    2010-09-01

    Mirror writing (MW) is a rare disorder in which a script runs in direction opposite to normal and individual letters are reversed. The disorder generally occurs after left-hemisphere lesions, is transient and is observed on the left hand, whereas usually motor impairments prevent assessment of direction of right handwriting. We describe a left-handed patient with complete left hand mirror writing, still evident 2 years after a hemorrhagic stroke in left nucleo-capsular region. Since the patient could write with his right hand he underwent several writing tasks with either hand, and a thorough assessment to clarify the nature of MW. MW was evident in writing to dictation with left hand only, both in right and left hemispace, but the patient could modify his behavior when a verbal instruction was provided. No mirror errors were found in reading words, in copying geometric figures and in spatial orientation tasks. MW in our patient could be accounted for by a failure in automatic transformation of grapho-motor programs to write with the left hand. A lack of concern (a sort of anosodiaphoria) and a poor cognitive flexibility could contribute to long-term persistence of MW. 2010 Elsevier Inc. All rights reserved.

  6. [Postoperative left ventricle-right auricle fistula: a case report].

    Science.gov (United States)

    Hidalgo, R; Peteiro, J; Aparici, M; Fernandéz, C A; Abaya, A; Martínez-Caro, D

    1990-06-01

    We present a case of a postoperative left ventricular--right atrial shunt in a 46 year-old patient operated for aortic valvulopathy. Through two-dimensional echocardiography and hemodynamic studies a communication between the left ventricle and the right atrium was observed. We review the literature about this rare anomaly.

  7. Evaluation of left ventricular structures in normotensive and ...

    African Journals Online (AJOL)

    This study was conducted with the objective to establish a nomogram for some left ventricular structures and their alterations in hypertension. Correlations between left ventricular structures and anthropometric variables in hypertension were also established. A sample of 320 normotensive and 80 hypertensive subjects ...

  8. Prevalence of left ventricular diastolic dysfunction in newly ...

    African Journals Online (AJOL)

    Background: Systemic hypertension is a common cause of left ventricular diastolic dysfunction. However, its prevalence in Nigerians with untreated systemic hypertension is unknown. Objective: To determine the prevalence of left ventricular diastolic dysfunction in newly diagnosed Nigerians with systemic hypertension ...

  9. Validation Study of Normogram For the Clinical Determination of Left ...

    African Journals Online (AJOL)

    In a study of 70 newly diagnosed hypertensive at the University of Maiduguri Teaching Hospital over a six month period, echocardiography detected increased left ventricular weight (= 225g) in 31 patients representing 44.3%. When compared with the rapid assessment of the estimation of Left Ventricular Mass (LVM) with a ...

  10. Left ventricular systolic function in sickle cell anaemia: An ...

    African Journals Online (AJOL)

    Background: Reliable diagnostic measures for the evaluation of left ventricular systolic performance in the setting of altered myocardial loading characteristics in sickle cell anaemia remains unresolved. Objective: The study was designed to assess left ventricular systolic function in adult sickle cell patients using ...

  11. [Considerations on the cerebral organization of left-handed persons].

    Science.gov (United States)

    Agostini, L; Piccirilli, M

    1983-01-01

    Left-handedness, being exception to the rule of right-handedness, has provoked several questions about its origins and the significance of its relationships with some individual traits, like cognitive style, personality, creativity, motor abilities. Investigations on left-handedness in recent years suggest that hand preference is linked to the peculiar functional organization of the two hemispheres of the brain.

  12. The organisational and ideological development of Green Left

    NARCIS (Netherlands)

    Lucardie, Anthonie; Voerman, Gerrit; Botella, Joan; Ramiro, Luis

    2003-01-01

    In 1991 the Communist Party of the Netherlands (CPN) dissolved itself into the new organisation GreenLeft, founded in 1990. Thus, GreenLeft may be considered the major ‘post-communist party’ in the Netherlands. Yet it is not the only one. A minority of former CPN-members established in 1992 the New

  13. Left Ventricular Function in Nigerians With Type 2 Diabetes Mellitus ...

    African Journals Online (AJOL)

    Background. Diabetes mellitus is an established risk factor for cardiovascular events and has been found to be independently associated with abnormal left ventricular function. We therefore decided to embark on this study to assess the left ventricular function in our diabetic patients. Method. The study design was ...

  14. A functional profile of Left Dislocation in Biblical Hebrew

    African Journals Online (AJOL)

    Andrason, A, Dr

    The primary aim of this paper is to provide a functional profile of verbal Left Dislocation (=LD) constructions in ... 2) the prototypical and non-prototypical discourse-pragmatic functions achieved by the construction in ... Keywords: Left Dislocation, Information Structure, Discourse Pragmatics, Biblical Hebrew. 1. Introduction.

  15. Postinfarction left ventricular free wall rupture repaired successfully.

    Science.gov (United States)

    Tireli, Emin; Kalko, Yusuf; Kafali, Eylül; Basaran, Murat

    2002-09-01

    Left ventricular free wall rupture is a well-recognized complication of myocardial infarction and a frequent cause of death. A 49-year-old man was successfully treated for a left ventricular free wall rupture that occurred on the third day after an anterior myocardial infarction. Concomitant myocardial revascularization was performed.

  16. Linear regression models for quantitative assessment of left ...

    African Journals Online (AJOL)

    Changes in left ventricular structures and function have been reported in cardiomyopathies. No prediction models have been established in this environment. This study established regression models for prediction of left ventricular structures in normal subjects. A sample of normal subjects was drawn from a large urban ...

  17. Left-handedness in twins: genes or environment?

    NARCIS (Netherlands)

    Orlebeke, J. F.; Knol, D. L.; Koopmans, J. R.; Boomsma, D. I.; Bleker, O. P.

    1996-01-01

    Twin family data can cast light on the longstanding problem about the influences of genes and environment on the etiology of left-handedness. Therefore, hand preference was assessed in 1700 adolescent twin pairs and their parents. Left-handedness (LH) appeared not significantly enhanced among twins

  18. Benign Multicystic Mesothelioma in the Left Round Ligament: Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Bae, So Young; Yi, Boem Ha; Lee, Hae Kyung; Park, Seong Jin; Cho, Gyu Seok; Kwak, Jeong Ja [Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of)

    2010-02-15

    Benign multicystic mesothelioma is a rare mesothelial lesion that forms multicystic masses in the upper abdomen, pelvis, and retroperitoneum. Most cases have a benign course. We present the ultrasound and MR findings of benign multicystic mesothelioma in the left round ligament, which caused a left inguinal hernia in a 46-year-old woman.

  19. Computer simulation of ECG manifestations of left ventricular electrical remodeling.

    Science.gov (United States)

    Bacharova, Ljuba; Szathmary, Vavrinec; Potse, Mark; Mateasik, Anton

    2012-01-01

    An increased QRS voltage is considered to be specific for the electrocardiogram (ECG) diagnosis of left ventricular hypertrophy (LVH). However, the QRS-complex patterns in patients with LVH cover a broader spectrum: increased QRS voltage, prolonged QRS duration, left axis deviation, and left anterior fascicular block- and left bundle branch block-like patterns, as well as pseudo-normal QRS patterns. The classical interpretation of the QRS patterns in LVH relates these changes to increased left ventricular mass (LVM) per se, while tending to neglect the modified active and passive electrical properties of the myocardium. However, it has been well documented that both active and passive electrical properties in LVH are altered. Using computer simulations, we have shown that an increased LVM is not the only determinant of QRS complex changes in LVH, as these changes could also be produced without changing the left ventricular mass, implying that these QRS patterns can be present in patients before their LVM exceeds the arbitrary upper normal limits. Our results link the experimental evidence on electrical remodeling with clinical interpretation of ECG changes in patients with LVH and stress the necessity of a complex interpretation of the QRS patterns considering both spatial and nonspatial determinants in terms of the spatial angle theory. We assume that hypertrophic electrical remodeling in combination with changes in left ventricular size and shape explains the variety of ECG patterns as well as the discrepancies between ECG and left ventricular mass. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Smoothed analysis of left-to-right maxima with applications

    NARCIS (Netherlands)

    Damerow, Valentina; Manthey, Bodo; Meyer auf der Heide, Friedhelm; Räcke, Heide Harald; Scheideler, Christian; Sohler, Christian; Tantau, Till

    A left-to-right maximum in a sequence of n numbers $s_1, ..., s_n$ is a number that is strictly larger than all preceding numbers. In this paper we present a smoothed analysis of the number of left-to-right maxima in the presence of additive random noise. We show that for every sequence of $n$

  1. Left subclavian artery revascularization as part of thoracic stent grafting

    NARCIS (Netherlands)

    Saouti, N.; Hindori, V.; Morshuis, W.J.; Heijmen, R.H.

    2015-01-01

    OBJECTIVES: Intentional covering of the left subclavian artery (LSA) as part of thoracic endovascular aortic repair (TEVAR) can cause (posterior) strokes or left arm malperfusion. LSA revascularization can be done as prophylaxis against, or as treatment of, these complications. We report our

  2. Patterns of left ventricular geometry in hypertensive patients in ...

    African Journals Online (AJOL)

    Systemic hypertension is associated with different left ventricular geometric adaptations, which are matched to systemic hemodynamics and ventricular load. Four geometric patterns have been described. The prevalence of these left ventricular geometric patterns in hypertension has been reported in other places but, the ...

  3. Anaesthesia for left thoracoscopic sympathectomy for refractory long ...

    African Journals Online (AJOL)

    Left thoracoscopic sympathectomy is an effective treatment for patients who are refractory to medical therapy or who need frequent epicardial internal cardio defibrillator intervention. The authors report three cases, one adult and two children, who underwent successful left thoracoscopic sympathectomy. All three patients ...

  4. EFFECTS OF RAIN ATTENUATION ON SATELLITE COMMUNICATION LINK

    Directory of Open Access Journals (Sweden)

    G. N. Ezeh

    2014-06-01

    Full Text Available Rain attenuation is a major challenge to microwave satellite communication especially at frequencies above 10 GHz, causing unavailability of signals most of the time. Rain attenuation predictions have become one of the vital considerations while setting up a satellite communication link. In this study, rain attenuation models, cumulative distribution curves and other analytical tools for successful prediction of rain attenuation are presented. A three year Rain rate data was obtained from the Nigeria Meteorological Agency (NIMET database in addition to experimental data. Of the three prediction models used in the study, Ajayi model gave the range of values closest to the experimental data. A correctional factor was determined as 1.0988 and used to modify the Ajayi model. This modification to Ajayi’s model enabled its rain attenuation values conform more closely to the experimental result.

  5. Scratch Drive Actuator Driven Self-assembled Variable Optical Attenuator

    Science.gov (United States)

    Lee, Chengkuo; Lai, Yen-Jyh; Wu, Chia-Yu; Lin, Yu-Shen; Tasi, Ming Hung; Huang, Ruey-Shing; Lin, Min-Shyong

    2004-06-01

    This paper describes the new concept and design for a self-assembled variable optical attenuator (VOA) derived by using surface micromachining technology. A residual stress-induced flexure curved beam with corrugated trench anchors can lift up the reflective mirror shutter. This self-assembled reflective shutter can be driven by a set of scratch drive actuator (SDA), then slides into the spacing between input and output fiber ends. The attenuation range of proposed microelectromechanical systems (MEMS) VOA is determined by the vertical position of self-assembled pop-up polysilicon reflective shutter in which it is controlled by the value of applied dc voltage. This new VOA demonstrates continuous attenuation capability and wide attenuation range based on using an electrostatic actuator that is a new residual stress-induced flexure curved beam with corrugated-trench anchors. This device exhibits attenuation range of 70 dB and insertion loss less than 1 dB.

  6. Left ventricular scar impact on left ventricular synchronization parameters and outcomes of cardiac resynchronization therapy.

    Science.gov (United States)

    Ahmed, Walid; Samy, Wael; Tayeh, Osama; Behairy, Noha; Abd El Fattah, Alia

    2016-11-01

    Left ventricular scar, including global scar and lateral wall, plays an important role in predicting response to cardiac resynchronization therapy (CRT). Thirty patients underwent CRT implantation. Assessment of left ventricular (LV) dyssynchrony was done through Gated SPECT LV phase analysis. Pre-implantation cardiac magnetic resonance (CMR) with late gadolinium enhancement technique to examine LV scar burden. Echocardiographic examination of LV end-systolic volume (LVES) prior to CRT and 6 months later. Thirty patients received CRT (mean age 58.7±9.0, 24 males). Reverse LV remodeling (decline ≥15% from baseline VES) was documented in 19 patients. Temporal changes in LV dyssynchrony parameters were correlated to LV reverse remodeling. Applying ROC for predicting CRT non-response showed a cutoff 36.5% of global LV scar burden had a sensitivity of 81.8% and specificity of 68.4%. A cutoff for lateral wall scar burden 40.5% of whole lateral wall had a sensitivity of 72.7% and specificity of 68.4%. Reverse LV remodeling is associated with temporal improvements in LV dyssynchrony parameters. LV scar had an unfavorable impact on CRT response. Both global and lateral wall scar burden could predict CRT nonresponse status. Copyright © 2016. Published by Elsevier Ireland Ltd.

  7. Surgical Left Atrial Appendage Exclusion Does Not Impair Left Atrial Contraction Function: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Gijs E. De Maat

    2015-01-01

    Full Text Available Background. In order to reduce stroke risk, left atrial appendage amputation (LAAA is widely adopted in recent years. The effect of LAAA on left atrial (LA function remains unknown. The objective of present study was to assess the effect of LAAA on LA function. Methods. Sixteen patients with paroxysmal AF underwent thoracoscopic, surgical PVI with LAAA (LAAA group, and were retrospectively matched with 16 patients who underwent the same procedure without LAA amputation (non-LAAA group. To objectify LA function, transthoracic echocardiography with 2D Speckle Tracking was performed before surgery and at 12 months follow-up. Results. Mean age was 57 ± 9 years, 84% were male. Baseline characteristics did not differ significantly except for systolic blood pressure (p=0.005. In both groups, the contractile LA function and LA ejection fraction were not significantly reduced. However, the conduit and reservoir function were significantly decreased at follow-up, compared to baseline. The reduction of strain and strain rate was not significantly different between groups. Conclusions. In this retrospective, observational matched group comparison with a convenience sample size of 16 patients, findings suggest that LAAA does not impair the contractile LA function when compared to patients in which the appendage was unaddressed. However, the LA conduit and reservoir function are reduced in both the LAAA and non-LAAA group. Our data suggest that the LAA can be removed without late LA functional consequences.

  8. Effect of Left Ventricular Outflow Tract Obstruction on Left Atrial Mechanics in Hypertrophic Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Lynne K. Williams

    2015-01-01

    Full Text Available Left atrial (LA volumes are known to be increased in hypertrophic cardiomyopathy (HCM and are a predictor of adverse outcome. In addition, LA function is impaired and is presumed to be due to left ventricular (LV diastolic dysfunction as a result of hypertrophy and myocardial fibrosis. In the current study, we assess the incremental effect of outflow tract obstruction (and concomitant mitral regurgitation on LA function as assessed by LA strain. Patients with HCM (50 obstructive, 50 nonobstructive were compared to 50 normal controls. A subset of obstructive patients who had undergone septal myectomy was also studied. Utilising feature-tracking software applied to cardiovascular magnetic resonance images, LA volumes and functional parameters were calculated. LA volumes were significantly elevated and LA ejection fraction and strain were significantly reduced in patients with HCM compared with controls and were significantly more affected in patients with obstruction. LA volumes and function were significantly improved after septal myectomy. LVOT obstruction and mitral regurgitation appear to further impair LA mechanics. Septal myectomy results in a significant reduction in LA volumes, paralleled by an improvement in function.

  9. Left ventricular volume and function after endoventricular patch plasty for dyskinetic anteroapical left ventricular aneurysm in sheep.

    Science.gov (United States)

    Zhang, Peng; Guccione, Julius M; Nicholas, Susan I; Walker, Joseph C; Crawford, Philip C; Shamal, Amin; Saloner, David A; Wallace, Arthur W; Ratcliffe, Mark B

    2005-10-01

    Endoventricular patch plasty (the Dor procedure) has gained favor as a surgical treatment for heart failure associated with large anteroapical myocardial infarction. We tested the hypothesis that the Dor procedure reduces left ventricular volume, increases end-systolic elastance, decreases diastolic compliance, and maintains left ventricular function. In 6 male Dorsett sheep, the left anterior descending coronary artery and its second diagonal branch were ligated 40% of the distance from apex to base. Sixteen weeks after myocardial infarction, a Dor procedure was performed with a Dacron patch that was 50% of the infarct neck dimension. Absolute left ventricular volume was measured with magnetic resonance imaging, and left ventricular pressure and relative left ventricular volume changes during pharmacologic preload reduction were measured with a volume conductance catheter 2 weeks before and 2 and 6 weeks after the Dor procedure. End-systolic elastance, diastolic compliance, and Starling relationships were calculated from the resultant left ventricular pressure/volume loops. Two weeks after the Dor procedure, the left ventricular volume at end systole and end diastole was significantly reduced, and there was no redilation at 6 weeks. Six weeks after the Dor procedure, the ejection fraction was significantly increased. Although stroke volume increased slightly at 6 weeks, the change was not significant. The slopes of end-systolic elastance, diastolic compliance, and Starling relationships were unchanged at 2 and 6 weeks. The Dor procedure significantly reduces left ventricular volume. Unlike linear repair, left ventricular volume changes seem stable. The ejection fraction is improved, and left ventricular function (stroke volume and the Starling relationship) is maintained.

  10. Diagnostic accuracy of computer-assisted electrocardiography in the diagnosis of left ventricular hypertrophy in left bundle branch block.

    Science.gov (United States)

    Rodríguez-Padial, Luis; Rodríguez-Picón, Blanca; Jerez-Valero, Miguel; Casares-Medrano, Julio; Akerström, Finn O; Calderon, Alberto; Barrios, Vivencio; Sarría-Santamera, Antonio; González-Juanatey, José R; Coca, Antonio; Andrés, Josep; Ruiz-Baena, Jessica

    2012-01-01

    Left ventricular hypertrophy has important prognostic implications. Although electrocardiography is the technique most often recommended in the diagnosis of hypertrophy, its diagnostic accuracy is hampered in the presence of a left bundle branch block. In 1875 consecutive patients (56±16 years) undergoing studies to rule out heart disease and/or hypertension, 2-dimensional echocardiography and electrocardiography were performed simultaneously in an outpatient clinic. Digitized electrocardiograms were interpreted using an online computer-assisted platform (ELECTROPRES). Sensitivity, specificity, likelihood ratios, and predictive values of standard electrocardiographic criteria and of some diagnostic algorithms for left ventricular hypertrophy were determined and compared with the findings in patients with neither left bundle branch block nor myocardial infarction. Left bundle branch block was present in 233 (12%) patients. Left ventricular hypertrophy was detected more frequently in patients with left bundle branch block (60% vs 31%). In patients with left bundle branch block, sensitivities were low but similar to those observed in patients without it, and ranged from 6.4% to 70.9%, whereas specificities were high, ranging from 57.6% to 100%. Positive likelihood ratios ranged from 1.33 to 4.94, and negative likelihood ratios from 0.50 to 0.98. Diagnostic algorithms, voltage-duration products, and certain compound criteria had the best sensitivities. Left ventricular hypertrophy can be diagnosed in the presence of left bundle branch block with an accuracy at least similar to that observed in patients without this conduction defect. Computer-assisted interpretation of the electrocardiogram may be useful in the diagnosis of left ventricular hypertrophy as it enables the implementation of more accurate algorithms. Copyright © 2011 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

  11. CABG surgery in a patient with left iliac artery occlusion

    Directory of Open Access Journals (Sweden)

    Oscar F. De La Peña Brush

    2015-09-01

    Full Text Available We present the case of an 82 years old male with Congestive Heart Failure (Left Ventricle Ejection Fraction: 20% and Acute Pulmonary Edema secondary to Acute Myocardial Infarction that required Coronary Artery Bypass Graft (CABG surgery. Past Medical History included Aortoiliac Occlusive Ddisease with total occlusion of the Left Iliac Artery and collateral circulation to the left inferior limb through the Left Internal Mammary Artery (LIMA. CABG was perfomed without harvesting the LIMA due to high risk of leg ischemia. An attempt to revascularize the left limb previous to the cardiac surgery in other to do so. Would have been too risky in this case. After 2 months follow up, patient showed good clinical outcomes.

  12. Phonological decisions require both the left and right supramarginal gyri

    DEFF Research Database (Denmark)

    Hartwigsen, Gesa; Baumgaertner, Annette; Price, Cathy J

    2010-01-01

    the right or left SMG. Taken together, these findings provide converging evidence that the right SMG contributes to accurate and efficient phonological decisions in the healthy brain, with no evidence that the left and right SMG can compensate for one another during TMS. Our findings motivate detailed......Recent functional imaging studies demonstrated that both the left and right supramarginal gyri (SMG) are activated when healthy right-handed subjects make phonological word decisions. However, lesion studies typically report difficulties with phonological processing after left rather than right...... during phonological, semantic, and perceptual decisions. To test laterality and anatomical specificity, we compared the effect of TMS over the left, right, or bilateral SMG and angular gyri. The accuracy and reaction times of phonological decisions were selectively disrupted relative to semantic...

  13. Left and right ventricular diastolic function in hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Rudhani Ibrahim

    2010-01-01

    Full Text Available The aim of this prospective study was the assessment of left ventricular and right ventricular diastolic function in patients on hemodialysis (HD and the correlation of this func-tion with the duration of HD. The study included 42 patients (22 females and 20 males with chro-nic renal failure (CRF, treated with HD, and 40 healthy subjects (24 females and 16 males with no history of cardiovascular disease and with normal renal function, who constituted the control group. The groups were matched for age and sex. All study patients and control subjects under-went detailed history taking and physical examination. They also underwent electrocardiogram, echocardiography and biochemical and hematological blood analyses. Significant differences were noted between the two groups in the two-dimensional and M-mode echocardiography findings concerning aortic root dimension, transverse diameter of the left atrium, thickness of the inter-ventricular septum, thickness of the left ventricular posterior wall, left ventricular diastolic diameter, left ventricular systolic diameter, shortening fraction, ejection fraction as well as findings from the pulse Doppler study, including E wave, A wave, E/A ratio, deceleration time of E wave (DT-E, acceleration time of E wave (AT-E, tricuspid E and A waves (E tr and A tr and E tr /A tr , ratio. There were significant changes in HD patients without arterial hypertension as well in the control group subjects. Our study suggests that the left ventricular and left atrial dimensions as well as the left ventricular wall thickness are augmented in patients with CRF treated with HD compared with the control group. Additionally, the left and right ventricular diastolic function is also reduced in these patients. These differences were also noted in patients with CRF without arterial hypertension. Left ventricular diastolic dysfunction had no correlation with the duration of HD.

  14. Left-Handedness in Professional and Amateur Tennis

    Science.gov (United States)

    Loffing, Florian; Hagemann, Norbert; Strauss, Bernd

    2012-01-01

    Negative frequency-dependent effects rather than innate predispositions may provide left-handers with an advantage in one-on-one fighting situations. Support mainly comes from cross-sectional studies which found significantly enhanced left-hander frequencies among elite athletes exclusively in interactive sports such as baseball, cricket, fencing and tennis. Since professional athletes’ training regimes continuously improve, however, an important unsolved question is whether the left-handers’ advantage in individual sports like tennis persists over time. To this end, we longitudinally tracked left-hander frequencies in year-end world rankings (men: 1973–2011, ladies: 1975–2011) and at Grand Slam tournaments (1968–2011) in male and female tennis professionals. Here we show that the positive impact of left-handed performance on high achievement in elite tennis was moderate and decreased in male professionals over time and was almost absent in female professionals. For both sexes, left-hander frequencies among year-end top 10 players linearly decreased over the period considered. Moreover, left-handedness was, however, no longer seems associated with higher probability of attaining high year-end world ranking position in male professionals. In contrast, cross-sectional data on left-hander frequencies in male and female amateur players suggest that a left-handers’ advantage may still occur on lower performance levels. Collectively, our data is in accordance with the frequency-dependent hypothesis since reduced experience with left-handers in tennis is likely to be compensated by players’ professionalism. PMID:23145151

  15. Left neglect dyslexia: Perseveration and reading error types.

    Science.gov (United States)

    Ronchi, Roberta; Algeri, Lorella; Chiapella, Laura; Gallucci, Marcello; Spada, Maria Simonetta; Vallar, Giuseppe

    2016-08-01

    Right-brain-damaged patients may show a reading disorder termed neglect dyslexia. Patients with left neglect dyslexia omit letters on the left-hand-side (the beginning, when reading left-to-right) part of the letter string, substitute them with other letters, and add letters to the left of the string. The aim of this study was to investigate the pattern of association, if any, between error types in patients with left neglect dyslexia and recurrent perseveration (a productive visuo-motor deficit characterized by addition of marks) in target cancellation. Specifically, we aimed at assessing whether different productive symptoms (relative to the reading and the visuo-motor domains) could be associated in patients with left spatial neglect. Fifty-four right-brain-damaged patients took part in the study: 50 out of the 54 patients showed left spatial neglect, with 27 of them also exhibiting left neglect dyslexia. Neglect dyslexic patients who showed perseveration produced mainly substitution neglect errors in reading. Conversely, omissions were the prevailing reading error pattern in neglect dyslexic patients without perseveration. Addition reading errors were much infrequent. Different functional pathological mechanisms may underlie omission and substitution reading errors committed by right-brain-damaged patients with left neglect dyslexia. One such mechanism, involving the defective stopping of inappropriate responses, may contribute to both recurrent perseveration in target cancellation, and substitution errors in reading. Productive pathological phenomena, together with deficits of spatial attention to events taking place on the left-hand-side of space, shape the manifestations of neglect dyslexia, and, more generally, of spatial neglect. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Left and right ventricular diastolic function in hemodialysis patients.

    Science.gov (United States)

    Rudhani, Ibrahim Destan; Bajraktari, Gani; Kryziu, Emrush; Zylfiu, Bejtush; Sadiku, Shemsedin; Elezi, Ymer; Rexhepaj, Nehat; Vitia, Arber; Emini, Merita; Abazi, Murat; Berbatovci-Ukimeraj, M; Kryeziu, Kaltrina; Hsanagjekaj, Venera; Korca, Hajrije; Ukimeri, Aferdita

    2010-11-01

    The aim of this prospective study was the assessment of left ventricular and right ventricular diastolic function in patients on hemodialysis (HD) and the correlation of this function with the duration of HD. The study included 42 patients (22 females and 20 males) with chronic renal failure (CRF), treated with HD, and 40 healthy subjects (24 females and 16 males) with no history of cardiovascular disease and with normal renal function, who constituted the control group. The groups were matched for age and sex. All study patients and control subjects underwent detailed history taking and physical examination. They also underwent electrocardiogram, echocardiography and biochemical and hematological blood analyses. Significant differences were noted between the two groups in the two-dimensional and M-mode echocardiography findings concerning aortic root dimension, transverse diameter of the left atrium, thickness of the interventricular septum, thickness of the left ventricular posterior wall, left ventricular diastolic diameter, left ventricular systolic diameter, shortening fraction, ejection fraction as well as findings from the pulse Doppler study, including E wave, A wave, E/A ratio, deceleration time of E wave (DT-E), acceleration time of E wave (AT-E), tricuspid E and A waves (E tr and A tr ) and E tr /A tr , ratio. There were significant changes in HD patients without arterial hypertension as well in the control group subjects. Our study suggests that the left ventricular and left atrial dimensions as well as the left ventricular wall thickness are augmented in patients with CRF treated with HD compared with the control group. Additionally, the left and right ventricular diastolic function is also reduced in these patients. These differences were also noted in patients with CRF without arterial hypertension. Left ventricular diastolic dysfunction had no correlation with the duration of HD.

  17. Left-handedness in professional and amateur tennis.

    Directory of Open Access Journals (Sweden)

    Florian Loffing

    Full Text Available Negative frequency-dependent effects rather than innate predispositions may provide left-handers with an advantage in one-on-one fighting situations. Support mainly comes from cross-sectional studies which found significantly enhanced left-hander frequencies among elite athletes exclusively in interactive sports such as baseball, cricket, fencing and tennis. Since professional athletes' training regimes continuously improve, however, an important unsolved question is whether the left-handers' advantage in individual sports like tennis persists over time. To this end, we longitudinally tracked left-hander frequencies in year-end world rankings (men: 1973-2011, ladies: 1975-2011 and at Grand Slam tournaments (1968-2011 in male and female tennis professionals. Here we show that the positive impact of left-handed performance on high achievement in elite tennis was moderate and decreased in male professionals over time and was almost absent in female professionals. For both sexes, left-hander frequencies among year-end top 10 players linearly decreased over the period considered. Moreover, left-handedness was, however, no longer seems associated with higher probability of attaining high year-end world ranking position in male professionals. In contrast, cross-sectional data on left-hander frequencies in male and female amateur players suggest that a left-handers' advantage may still occur on lower performance levels. Collectively, our data is in accordance with the frequency-dependent hypothesis since reduced experience with left-handers in tennis is likely to be compensated by players' professionalism.

  18. Increased prevalences of left-handedness and left-eye sighting dominance in individuals with Williams-Beuren syndrome

    NARCIS (Netherlands)

    J.W. van Strien (Jan)

    2005-01-01

    textabstractHandedness and eye sighting dominance were assessed in a sample of 50 individuals (25 male, 25 female; aged 5 – 38 years) with Williams-Beuren syndrome (WBS). The prevalences of left-handedness and left-eyedness were compared to the normative prevalences in the general population. We

  19. Compression of left main bronchus with collapse of left lung by a large descending thoracic aortic aneurysm: A case report

    Directory of Open Access Journals (Sweden)

    Khushal N. Pawar, Dilip L. Lakhkar, Sushil Nemane, Sandeep Shinde

    2013-07-01

    Full Text Available We report a case of 60 years old female who presented with a history of progressive breathlessness over a period of one year. CECT thorax revealed a large aneurysm of descending thoracic aorta which was causing compression of left main bronchus with resultant complete collapse of left lung. There was a contralateral shift of the trachea and mediastinum.

  20. Prognostic value of CT-derived left atrial and left ventricular measures in patients with acute chest pain

    NARCIS (Netherlands)

    Takx, Richard A. P.; Vliegenthart, Rozemarijn; Schoepf, U. Joseph; Nance, John W.; Bamberg, Fabian; Abro, Joseph A.; Carr, Christine M.; Litwin, Sheldon E.; Apfaltrer, Paul

    Purpose: To determine which left atrial (LA) and left ventricular (LV) parameters are associated with future major adverse cardiac event (MACE) and whether these measurements have independent prognostic value beyond risk factors and computed tomography (CT)-derived coronary artery disease measures.

  1. Exercise training prior to myocardial infarction attenuates cardiac deterioration and cardiomyocyte dysfunction in rats.

    Science.gov (United States)

    Bozi, Luiz Henrique Marchesi; Maldonado, Izabel Regina dos Santos Costa; Baldo, Marcelo Perim; Silva, Márcia Ferreira da; Moreira, José Bianco Nascimento; Novaes, Rômulo Dias; Ramos, Regiane Maria Soares; Mill, José Geraldo; Brum, Patricia Chakur; Felix, Leonardo Bonato; Gomes, Thales Nicolau Prímola; Natali, Antônio José

    2013-04-01

    The present study was performed to investigate 1) whether aerobic exercise training prior to myocardial infarction would prevent cardiac dysfunction and structural deterioration and 2) whether the potential cardiac benefits of aerobic exercise training would be associated with preserved morphological and contractile properties of cardiomyocytes in post-infarct remodeled myocardium. Male Wistar rats underwent an aerobic exercise training protocol for eight weeks. The rats were then assigned to sham surgery (SHAM), sedentary lifestyle and myocardial infarction or exercise training and myocardial infarction groups and were evaluated 15 days after the surgery. Left ventricular tissue was analyzed histologically, and the contractile function of isolated myocytes was measured. Student's t-test was used to analyze infarct size and ventricular wall thickness, and the other parameters were analyzed by the Kruskal-Wallis test followed by Dunn's test or a one-way analysis of variance followed by Tukey's test (pmyocardial infarction extension, a thicker infarcted wall and less collagen accumulation as compared to myocardial infarctions in sedentary animals. Myocardial infarction-induced left ventricular dilation and cardiac dysfunction, as evaluated by +dP/dt and -dP/dt, were both prevented by previous aerobic exercise training. Moreover, aerobic exercise training preserved cardiac myocyte shortening, improved the maximum shortening and relengthening velocities in infarcted hearts and enhanced responsiveness to calcium. Previous aerobic exercise training attenuated the cardiac dysfunction and structural deterioration promoted by myocardial infarction, and such benefits were associated with preserved cardiomyocyte morphological and contractile properties.

  2. The Cardiac Sympathetic Nerve Activity in the Elderly Is Attenuated in the Right Lateral Decubitus Position

    Science.gov (United States)

    Sasaki, Konosuke; Haga, Mayu; Bao, Sarina; Sato, Haruka; Saiki, Yoshikatsu; Maruyama, Ryoko

    2017-01-01

    Objectives: The aim of this study was to evaluate the effect of the supine, left lateral decubitus, and right lateral decubitus positions on autonomic nervous activity in elderly adults by using spectral analysis of heart rate variability (HRV). Method: Forty-five adults aged 73.6 ± 5.7 years were enrolled. After lying in the supine position, all participants moved to the lateral decubitus positions in a random order and maintained the positions for 10 min, while electrocardiographic data were recorded to measure HRV. Results: The lowest heart rate continued for 10 min when participants were in the left lateral decubitus position compared with the other two positions (p < .001), while the HRV indexes remained unchanged. The low-frequency HRV to high-frequency HRV ratio (LF/HF) for the right lateral decubitus position was significantly lower than that for the other positions. Discussion: The right lateral decubitus position may attenuate sympathetic nerve activity in elderly adults. PMID:28516131

  3. Sulforaphane attenuates EGFR signaling in NSCLC cells.

    Science.gov (United States)

    Chen, Chi-Yuan; Yu, Zhu-Yun; Chuang, Yen-Shu; Huang, Rui-Mei; Wang, Tzu-Chien V

    2015-06-03

    EGFR, a receptor tyrosine kinase (RTK), is frequently overexpressed and mutated in non-small cell lung cancer (NSCLC). Tyrosine kinase inhibitors (TKIs) have been widely used in the treatment of many cancers, including NSCLC. However, intrinsic and acquired resistance to TKI remains a common obstacle. One strategy that may help overcome EGFR-TKI resistance is to target EGFR for degradation. As EGFR is a client protein of heat-shock protein 90 (HSP90) and sulforaphane is known to functionally regulate HSP90, we hypothesized that sulforaphane could attenuate EGFR-related signaling and potentially be used to treat NSCLC. Our study revealed that sulforaphane displayed antitumor activity against NSCLC cells both in vitro and in vivo. The sensitivity of NSCLC cells to sulforaphane appeared to positively correlate with the inhibition of EGFR-related signaling, which was attributed to the increased proteasomal degradation of EGFR. Combined treatment of NSCLC cells with sulforaphane plus another HSP90 inhibitor (17-AAG) enhanced the inhibition of EGFR-related signaling both in vitro and in vivo. We have shown that sulforaphane is a novel inhibitory modulator of EGFR expression and is effective in inhibiting the tumor growth of EGFR-TKI-resistant NSCLC cells. Our findings suggest that sulforaphane should be further explored for its potential clinical applications against NSCLC.

  4. Impact energy attenuation performance of football headgear

    Science.gov (United States)

    McIntosh, A.; McCrory, P.

    2000-01-01

    Objectives—Commercially available football head protectors were tested to determine their impact energy attenuation performance and ability to reduce the likelihood of concussion. Methods—Prospective study using standardised impact test methods with both rigid (magnesium) and Hybrid III headforms. Results—Eight commercially available head protectors from six manufacturers were tested. The magnitude of the headform accelerations increased as the drop height was increased, ranging from a minimum of 64 g from a height of 0.2 m to a maximum of 1132 g from a height of 0.6 m. The head injury criterion and maximum headform acceleration values followed a similar trend. A steep increase was noted in the magnitude of maximum headform acceleration and head injury criterion when the drop height was increased from 0.4 to 0.5 m. This indicates that the foam material was completely compressed at an impact energy above about 20 J and therefore offers little protection against impacts of greater severity. Repeated tests using a drop height of 0.3 m showed that some helmets exhibit a "memory" effect, whereby impact performance is reduced by up to 50% with repeated impacts. Conclusions—Laboratory tests indicate that current commercially available football headgear performance will not reduce the likelihood of concussion. The absence of internationally recognised standards for soft headgear designed to ameliorate concussion is a major deficiency in sports injury prevention. Key Words: football; headgear; helmet; head; concussion PMID:11049142

  5. Mid-European seismic attenuation anomaly

    Science.gov (United States)

    Málek, Jiří; Brokešová, Johana; Vackář, Jiří

    2017-08-01

    Macroseismic studies of various historical earthquakes with epicenters in the Eastern Alps region have shown a significant elongation of isoseismals in the North-West direction. Such an anomalous attenuation of seismic waves in Central Europe is investigated on the basis of instrumental records of two moderate-size earthquakes in the Vienna Basin, which occurred in September and October 2013. It has been found that for both earthquakes the peak amplitudes of both velocity and acceleration are considerably higher to the North-West of the epicenters compared to the other directions. The peak ground velocity amplitudes at comparable epicentral distances but different azimuths may vary by as much as one order of magnitude. The inspection of individual seismograms suggests that the phenomenon is associated mainly with the propagation of S waves. Significant differences in frequency content of the seismic waves radiated to different azimuths are also demonstrated. The maximum predominant frequency was not observed at stations closest to the epicenters but about 250 km away, in the Bohemian Massif. The possible causes of these observations are briefly discussed on the basis of an elementary data analysis but further research and in-depth analysis is required to elucidate the causes of these phenomena.

  6. Silibinin attenuates allergic airway inflammation in mice

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yun Ho [Department of Anatomy, Medical School, Institute for Medical Sciences, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Jin, Guang Yu [Department of Radiology, Yanbian University Hospital, YanJi 133002 (China); Guo, Hui Shu [Centralab, The First Affiliated Hospital of Dalian Medical University, Dalian 116011 (China); Piao, Hong Mei [Department of Respiratory Medicine, Yanbian University Hospital, YanJi 133000 (China); Li, Liang chang; Li, Guang Zhao [Department of Anatomy and Histology and Embryology, Yanbian University School of Basic Medical Sciences, 977 Gongyuan Road, YanJi 133002, Jilin (China); Lin, Zhen Hua [Department of Pathology, Yanbian University School of Basic Medical Sciences, YanJi 133000 (China); Yan, Guang Hai, E-mail: ghyan@ybu.edu.cn [Department of Anatomy and Histology and Embryology, Yanbian University School of Basic Medical Sciences, 977 Gongyuan Road, YanJi 133002, Jilin (China)

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer Silibinin diminishes ovalbumin-induced inflammatory reactions in the mouse lung. Black-Right-Pointing-Pointer Silibinin reduces the levels of various cytokines into the lung of allergic mice. Black-Right-Pointing-Pointer Silibinin prevents the development of airway hyperresponsiveness in allergic mice. Black-Right-Pointing-Pointer Silibinin suppresses NF-{kappa}B transcriptional activity. -- Abstract: Allergic asthma is a chronic inflammatory disease regulated by coordination of T-helper2 (Th2) type cytokines and inflammatory signal molecules. Silibinin is one of the main flavonoids produced by milk thistle, which is reported to inhibit the inflammatory response by suppressing the nuclear factor-kappa B (NF-{kappa}B) pathway. Because NF-{kappa}B activation plays a pivotal role in the pathogenesis of allergic inflammation, we have investigated the effect of silibinin on a mouse ovalbumin (OVA)-induced asthma model. Airway hyperresponsiveness, cytokines levels, and eosinophilic infiltration were analyzed in bronchoalveolar lavage fluid and lung tissue. Pretreatment of silibinin significantly inhibited airway inflammatory cell recruitment and peribronchiolar inflammation and reduced the production of various cytokines in bronchoalveolar fluid. In addition, silibinin prevented the development of airway hyperresponsiveness and attenuated the OVA challenge-induced NF-{kappa}B activation. These findings indicate that silibinin protects against OVA-induced airway inflammation, at least in part via downregulation of NF-{kappa}B activity. Our data support the utility of silibinin as a potential medicine for the treatment of asthma.

  7. Obesity attenuates gender differences in cardiovascular mortality.

    Science.gov (United States)

    Song, Xin; Tabák, Adam G; Zethelius, Björn; Yudkin, John S; Söderberg, Stefan; Laatikainen, Tiina; Stehouwer, Coen D A; Dankner, Rachel; Jousilahti, Pekka; Onat, Altan; Nilsson, Peter M; Satman, Ilhan; Vaccaro, Olga; Tuomilehto, Jaakko; Qiao, Qing

    2014-10-19

    To estimate cardiovascular disease (CVD) mortality in relation to obesity and gender. Data from 11 prospective cohorts from four European countries including 23 629 men and 21 965 women, aged 24 to 99 years, with a median follow-up of 7.9 years were analyzed. Hazards ratios (HR) for CVD mortality in relation to baseline body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) were estimated using Cox proportional hazards models with age as the timescale. Men had higher CVD mortality than women in all four BMI categories (obesity defined by WC, WHR or WHtR. The gender difference was slightly smaller in obese than in non-obese individuals; but the interaction was statistically significant only between gender and WC (p = 0.02), and WHtR (p = 0.01). None of the interaction terms was significant among non-diabetic individuals. Men had higher CVD mortality than women across categories of anthropometric measures of obesity. The gender difference was attenuated in obese individuals, which warrants further investigation.

  8. Statins attenuate polymethylmethacrylate-mediated monocyte activation.

    LENUS (Irish Health Repository)

    Laing, Alan J

    2012-02-03

    BACKGROUND: Periprosthetic osteolysis precipitates aseptic loosening of components, increases the risk of periprosthetic fracture and, through massive bone loss, complicates revision surgery and ultimately is the primary cause for failure of joint arthroplasty. The anti-inflammatory properties of HMG-CoA reductase inhibitors belonging to the statin family are well recognized. We investigated a possible role for status in initiating the first stage of the osteolytic cycle, namely monocytic activation. METHODS: We used an in vitro model of the human monocyte\\/macrophage inflammatory response to poly-methylmethacrylate (PMMA) particles after pretreat-ing cells with cerivastatin, a potent member of the statin family. Cell activation based upon production of TNF-alpha and MCP-1 cytokines was analyzed and the intracellular Raf-MEK-ERK signal transduction pathway was evaluated using western blot analysis, to identify its role in cell activation and in any cerivastatin effects observed. RESULTS: We found that pretreatment with cerivastatin significantly abrogates the production of inflammatory cytokines TNF-alpha and MCP-1 by human monocytes in response to polymethylmethacrylate particle activation. This inflammatory activation and attenuation appear to be mediated through the intracellular Raf-MEK-ERK pathway. INTERPRETATION: We propose that by intervening at the upstream activation stage, subsequent osteoclast activation and osteolysis can be suppressed. We believe that the anti-inflammatory properties of statins may potentially play a prophylactic role in the setting of aseptic loosening, and in so doing increase implant longevity.

  9. Minocycline Attenuates Iron-Induced Brain Injury.

    Science.gov (United States)

    Zhao, Fan; Xi, Guohua; Liu, Wenqaun; Keep, Richard F; Hua, Ya

    2016-01-01

    Iron plays an important role in brain injury after intracerebral hemorrhage (ICH). Our previous study found minocycline reduces iron overload after ICH. The present study examined the effects of minocycline on the subacute brain injury induced by iron. Rats had an intracaudate injection of 50 μl of saline, iron, or iron + minocycline. All the animals were euthanized at day 3. Rat brains were used for immunohistochemistry (n = 5-6 per each group) and Western blotting assay (n = 4). Brain swelling, blood-brain barrier (BBB) disruption, and iron-handling proteins were measured. We found that intracerebral injection of iron resulted in brain swelling, BBB disruption, and brain iron-handling protein upregulation (p minocycline with iron significantly reduced iron-induced brain swelling (n = 5, p Minocycline significantly decreased albumin protein levels in the ipsilateral basal ganglia (p minocycline co-injected animals. In conclusion, the present study suggests that minocycline attenuates brain swelling and BBB disruption via an iron-chelation mechanism.

  10. Acute decrease of left ventricular mechanical dyssynchrony and improvement of contractile state and energy efficiency after left ventricular restoration.

    Science.gov (United States)

    Schreuder, Jan J; Castiglioni, Alessandro; Maisano, Francesco; Steendijk, Paul; Donelli, Andrea; Baan, Jan; Alfieri, Ottavio

    2005-01-01

    Surgical left ventricular restoration by means of endoventricular patch aneurysmectomy in patients with postinfarction aneurysm should result in acute improved left ventricular performance by decreasing mechanical dyssynchrony and increasing energy efficiency. Nine patients with left ventricular postinfarction aneurysm were studied intraoperatively before and after ventricular restoration with a conductance volume catheter to analyze pressure-volume relationships, energy efficiency, and mechanical dyssynchrony. The end-systolic elastance was used as a load-independent index of contractile state. Left ventricular energy efficiency was calculated from stroke work and total pressure-volume area. Segmental volume changes perpendicular to the long axis were used to calculate mechanical dyssynchrony. Statistical analysis was performed with the paired t test and least-squares linear regression. Endoventricular patch aneurysmectomy reduced end-diastolic volume by 37% (P energy efficiency increased by 36% (P energy efficiency, and relaxation, together with a decrease in left ventricular mechanical dyssynchrony.

  11. The "Left Ureteral Triangle" as an Anatomic Landmark for the Identification of the Left Ureter in Laparoscopic Distal Colectomies.

    Science.gov (United States)

    Tebala, Giovanni D

    2016-10-01

    Ureteral injury is one of the possible complications of distal colectomies. It may be caused by misidentification of the anatomic landmarks during the left lateral dissection, due to factor pertaining to the patient, the disease, and the surgeon. The only way to reduce the risk of this avoidable complication is the perfect knowledge and identification of the anatomy of the left ureter. In this article, we describe an anatomic triangle that can be a valid help in the identification of the ureter in the area where higher is the risk of iatrogenic injury. The left ureteric triangle can be prepared after the dissection of the left Toldt plane, as soon as the dissection reaches the superior mesorectum. Sides of this triangle are (a) superiorly, the dissected mesosigmoid, (b) right side, upper mesorectum and sacral promontorium, and (c) inferiorly, the margin of the incised posterior parietal peritoneum. The left ureter runs within this triangle.

  12. Left handedness in an identical twin discordant to his co-twin for handedness and schizophrenia, with neurological and psychometric evidence of left hemisphere damage.

    Science.gov (United States)

    Weller, M P

    1990-03-01

    A left handed, monozygotic, male twin developed schizophrenia, whilst his right handed brother was free of psychopathology. There was no family history of mental illness or left handedness. The affected twin had left side motor weakness and an EEG showed scattered irregularities, particularly on the left. Psychometry indicated left sided tempero-parietal dysfunction. The relationship between left temporal lobe damage and schizophrenia is considered.

  13. Left handedness in an identical twin discordant to his co-twin for handedness and schizophrenia, with neurological and psychometric evidence of left hemisphere damage.

    Science.gov (United States)

    Weller, M. P.

    1990-01-01

    A left handed, monozygotic, male twin developed schizophrenia, whilst his right handed brother was free of psychopathology. There was no family history of mental illness or left handedness. The affected twin had left side motor weakness and an EEG showed scattered irregularities, particularly on the left. Psychometry indicated left sided tempero-parietal dysfunction. The relationship between left temporal lobe damage and schizophrenia is considered. PMID:2362891

  14. Left handedness in an identical twin discordant to his co-twin for handedness and schizophrenia, with neurological and psychometric evidence of left hemisphere damage.

    OpenAIRE

    Weller, M. P.

    1990-01-01

    A left handed, monozygotic, male twin developed schizophrenia, whilst his right handed brother was free of psychopathology. There was no family history of mental illness or left handedness. The affected twin had left side motor weakness and an EEG showed scattered irregularities, particularly on the left. Psychometry indicated left sided tempero-parietal dysfunction. The relationship between left temporal lobe damage and schizophrenia is considered.

  15. Complete left bundle branch block with left QRS axis deviation: defining its clinical importance.

    Science.gov (United States)

    Parharidis, G; Nouskas, J; Efthimiadis, G; Styliadis, J; Gemitzis, K; Hatzimiltiadis, S; Karoulas, T; Tsifodimos, D

    1997-01-01

    Aim of this study was to elucidate the diagnostic significance of left axis deviation (LAD) in patients (pts) with chronic (> 6 months) left bundle branch block (LBBB). We retrospectively studied 2094 consecutive pts who underwent cardiac catheterization. All pts had left heart catheterization and coronary angiography, whereas right heart catheterization or endomyocardial biopsy were performed on indication. Our study group consisted of 43 pts with LBBB (29 men, 14 women, mean age 60.3 +/- 7.9 years). Pts with acute myocardial infarction or prior high degree AV-block were excluded. Initial evaluation included history, physical examination, chest X-ray, serial ECGs, 2D-echo and Doppler studies. ECG-criteria for LBBB were a QRS duration of > 0.12 secs, a predominantly negative QRS deflection in V1 and a widened R-wave in V6. LAD was considered present when the mean frontal QRS axis was between -30 degrees and -90 degrees. The mean frontal QRS axis was considered normal if it was between -29 degrees and +90 degrees. Twenty-nine pts had normal axis and 14 had LAD. According to angiographic data, among coronary disease pts, 12 (31.48%) had normal axis and 4 (28.57%) LAD (p = 0.041). Among mitral valve disease pts, 3 (10.35%) had normal axis and none LAD. Among pts with aortic valve disease, I (3.45%) had normal axis and 8 (57.15%) LAD (p = 0.0001). Among pts with dilated cardiomyopathy, 2 (6.9%) had normal axis and 1 (7.14%) LAD. Among pts with no organic heart disease, 11 (37.93%) had normal axis and 1 (7.14%) LAD (p = 0.035). The presence of LAD had a 41.9% sensitivity and a 91.6% specificity for the presence of organic heart disease. These findings point towards a statistically significant difference in the presence of organic heart disease in LBBB pts with LAD compared to normals. Aortic valve disease in LBBB pts seems to be frequently accompanied by LAD.

  16. Prognostic Implication of the QRS Axis and its Association with Myocardial Scarring in Patients with Left Bundle Branch Block.

    Science.gov (United States)

    Park, Chan Soon; Cha, Myung-Jin; Choi, Eue-Keun; Oh, Seil

    2017-03-01

    Left bundle branch block (LBBB) with left axis deviation (LAD) has a worse prognosis than LBBB with a normal axis, and myocardial dysfunction has been suggested as a cause of left axis deviation. This study investigated the prognostic significance of the QRS axis in patients with LBBB and analyzed its relationship with the amount of myocardial scarring. A total of 829 patients were diagnosed with LBBB at Seoul National University Hospital from October 2004 to June 2014. Of these, 314 who were asymptomatic and had no previous history of cardiac disease were included in the present study. Myocardial scarring was calculated using the Selvester QRS scoring system, and LAD was defined as a QRS axis between -180° and -30°. Of the total patients, 91 (29%) had LAD, and patients were followed for a median of 30 months. During follow-up, two patients were hospitalized for de novo heart failure, four had pacemaker implants, and 10 died. There was a significant inverse correlation between myocardial scar score and the QRS axis (r=-0.356, paxis (5.5% vs. 1.3%, log-rank p=0.010); the prognostic value was attenuated in multivariable analysis (hazard ratio 4.117; 95% confidence interval 0.955-17.743; p=0.058). Concomitant LAD is an indicator of poor prognosis for patients with LBBB and may be associated with greater myocardial scarring.

  17. Prolonged QRS duration (QRS >/=170 ms) and left axis deviation in the presence of left bundle branch block: A marker of poor left ventricular systolic function?

    Science.gov (United States)

    Das, M K; Cheriparambil, K; Bedi, A; Kassotis, J; Reddy, C V; Makan, M; Dunbar, C C; Saul, B

    2001-11-01

    Left bundle branch block (LBBB) is commonly associated with structural heart disease and left ventricular dysfunction. We propose that the QRS duration and degree of left-axis deviation (LAD) identify significant left ventricular systolic dysfunction in patients with LBBB. In this prospective study the ejection fraction (EF) of 300 consecutive patients with LBBB was evaluated by echocardiography. The relationship between QRS duration and LAD (axis between -30 degrees and -90 degrees ) and EF were derived. There was no significant difference in age, sex, presence of ischemic or nonischemic cardiomyopathy and valvular heart disease, and EF among the patients with or without LAD. The EF of patients with QRS >/=170 milliseconds with LAD (n = 20) and without LAD (n = 18) was 25% +/- 16% and 23% +/- 13%, respectively (P =.71). The mean EF (24% +/- 10%) of the patients with a QRS duration of >/=170 milliseconds (n = 38) was significantly lower than the mean EF (36% +/- 16%) of the patients with a QRS duration of axis was not significantly correlated with EF and did not have added predictive value. The QRS duration has a significant inverse relationship with EF and prolongation of QRS duration (>/=170 milliseconds) in the presence of LBBB is a marker of significant left ventricular systolic dysfunction. The presence of LAD in LBBB does not signify a further decrease in EF.

  18. A contrast source method for nonlinear acoustic wave fields in media with spatially inhomogeneous attenuation

    NARCIS (Netherlands)

    Demi, L.; Van Dongen, K.W.A.; Verweij, M.D.

    2011-01-01

    Experimental data reveals that attenuation is an important phenomenon in medical ultrasound. Attenuation is particularly important for medical applications based on nonlinear acoustics, since higher harmonics experience higher attenuation than the fundamental. Here, a method is presented to

  19. Radio wave propagation through vegetation: Factors influencing signal attenuation

    Science.gov (United States)

    Savage, Nick; Ndzi, David; Seville, Andrew; Vilar, Enric; Austin, John

    2003-10-01

    The paper describes an extensive wideband channel sounding measurement campaign to investigate signal propagation through vegetation. The measurements have been conducted at three frequencies (1.3, 2 and 11.6 GHz) at sites with different measurement geometries and tree species. The data have been used to evaluate current narrowband empirical vegetation attenuation models and study the prevailing propagation mechanisms. Evaluation of the modified exponential decay (MED), maximum attenuation (MA) and nonzero gradient (NZG) models show that on a site by site basis, the NZG model gives the best prediction of excess attenuation due to vegetation. The MA model has been found to be the worst of the three models. The studies have shown that the measurement site used to obtain the NZG model parameter values given in () [2001] is influenced by metal lampposts and passing traffic, and thus was based on corrupted data. The results show that the leaf state, measurement geometry and vegetation density are more important factors influencing signal attenuation than tree species or leaf shape. Generally, the 11.6 GHz signal was attenuated much more than the 1.3 and 2 GHz signals by vegetation in-leaf, but the differences in attenuation were not significant in the out-of-leaf state. A successful excess attenuation model due to vegetation must consider the measurement geometry and vegetation descriptive parameters as well as any contributions from ground reflection and/or diffraction over the top or round edges of the trees.

  20. Believing and perceiving: authorship belief modulates sensory attenuation.

    Directory of Open Access Journals (Sweden)

    Andrea Desantis

    Full Text Available Sensory attenuation refers to the observation that self-generated stimuli are attenuated, both in terms of their phenomenology and their cortical response compared to the same stimuli when generated externally. Accordingly, it has been assumed that sensory attenuation might help individuals to determine whether a sensory event was caused by themselves or not. In the present study, we investigated whether this dependency is reciprocal, namely whether sensory attenuation is modulated by prior beliefs of authorship. Participants had to judge the loudness of auditory effects that they believed were either self-generated or triggered by another person. However, in reality, the sounds were always triggered by the participants' actions. Participants perceived the tones' loudness attenuated when they believed that the sounds were self-generated compared to when they believed that they were generated by another person. Sensory attenuation is considered to contribute to the emergence of people's belief of authorship. Our results suggest that sensory attenuation is also a consequence of prior belief about the causal link between an action and a sensory change in the environment.

  1. Broadband Lg Attenuation Modeling in the Middle East

    Energy Technology Data Exchange (ETDEWEB)

    Pasyanos, M E; Matzel, E M; Walter, W R; Rodgers, A J

    2008-08-21

    We present a broadband tomographic model of Lg attenuation in the Middle East derived from source- and site-corrected amplitudes. Absolute amplitude measurements are made on hand-selected and carefully windowed seismograms for tens of stations and thousands of crustal earthquakes resulting in excellent coverage of the region. A conjugate gradient method is used to tomographically invert the amplitude dataset of over 8000 paths over a 45{sup o} x 40{sup o} region of the Middle East. We solve for Q variation, as well as site and source terms, for a wide range of frequencies ranging from 0.5-10 Hz. We have modified the standard attenuation tomography technique to more explicitly define the earthquake source expression in terms of the seismic moment. This facilitates the use of the model to predict the expected amplitudes of new events, an important consideration for earthquake hazard or explosion monitoring applications. The attenuation results have a strong correlation to tectonics. Shields have low attenuation, while tectonic regions have high attenuation, with the highest attenuation at 1 Hz is found in eastern Turkey. The results also compare favorably to other studies in the region made using Lg propagation efficiency, Lg/Pg amplitude ratios and two-station methods. We tomographically invert the amplitude measurements for each frequency independently. In doing so, it appears the frequency-dependence of attenuation is not compatible with the power law representation of Q(f), an assumption that is often made.

  2. An acoustic eikonal equation for attenuating orthorhombic media

    KAUST Repository

    Hao, Qi

    2017-04-06

    Attenuating orthorhombic models are often used to describe the azimuthal variation of the seismic wave velocity and amplitude in finely layered hydrocarbon reservoirs with vertical fractures. In addition to the P-wave related medium parameters, shear wave parameters are also present in the complex eikonal equation needed to describe the P-wave complex-valued traveltime in an attenuating orthorhombic medium, which increases the complexity of using the P-wave traveltime to invert for the medium parameters in practice. Here, we use the acoustic assumption to derive an acoustic eikonal equation that approximately governs the complex-valued traveltime of P-waves in an attenuating orthorhombic medium. For a homogeneous attenuating orthorhombic media, we solve the eikonal equation using a combination of the perturbation method and Shanks transform. For a horizontal attenuating orthorhombic layer, both the real and imaginary part of the complex-valued reflection traveltime have nonhyperbolic behaviors in terms of the source-receiver offset. Similar to the roles of normal moveout (NMO) velocity and anellipticity, the attenuation NMO velocity and the attenuation anellipticity characterize the variation of the imaginary part of the complex-valued reflection traveltime around zero source-receiver offset.

  3. Comparison of Nitrate Attenuation Characterization Methods for Groundwater Remediation

    Science.gov (United States)

    Carroll, K. C.; Jordan, F. L.; Glenn, E. P.; Waugh, J.; Brusseau, M. L.

    2008-12-01

    Nitrate released from a former uranium mine tailings stockpile has contaminated groundwater near Monument Valley, Arizona. The results of previous studies suggest that nitrate attenuation is occurring at the site, but the feasibility of using natural attenuation as a remediation strategy remains uncertain. This investigation characterized the occurrence and rate of natural attenuation at the site using several methods. Spatial and temporal nitrate concentration data collected from a transect of monitoring wells located along the plume centerline were analyzed to evaluate overall rates of natural attenuation. The occurrence and rate of denitrification was evaluated through microcosm experiments, nitrogen isotopic fractionation analysis, and solute transport modeling. First-order rate coefficients calculated for each method were comparable. The composite natural attenuation rate coefficient was larger than the denitrification rate coefficient, which suggests that a combination of biological decay and dispersion/diffusion processes control nitrate attenuation at the site. Model simulations were conducted to estimate the time required for nitrate concentrations in the plume to decrease to 10 mg/L under existing conditions, which was approximately 150 years. Additional simulations were conducted to assess the potential reduction in cleanup time that would result from implementing enhanced denitrification via either methanol or ethanol injection. The results indicated that cleanup would be attained in approximately one-third the time estimated for natural attenuation.

  4. Wave attenuation over porous seabeds: A numerical study

    Science.gov (United States)

    Torres-Freyermuth, Alec; Brocchini, Maurizio; Corvaro, Sara; Pintado-Patiño, Jose Carlos

    2017-09-01

    We investigate wave attenuation over porous seabeds by means of a phase- and depth- resolving numerical model that solves the Volume-Averaged Reynolds-Averaged Navier-Stokes (VARANS) equations. The numerical model is calibrated with laboratory data from Corvaro et al. (2010). The numerical model predicts the wave attenuation and the velocity field near the porous bed for different regular wave conditions. Subsequently, a parametric analysis on the physical characteristics of the porous media is made to investigate their relative role on wave attenuation. The results of the analysis indicate nonlinear dependencies of wave attenuation on both, total porosity and mean grain diameter. The widely used parabolic model in terms of the dispersiveness parameter predicts both types of dependencies, effectively. Hence, new parametric formulations are derived for the determination of the coefficients involved in the parabolic model for each type of dependence. On the other hand, the role of the spectral shape on the wave spectrum bulk dissipation is investigated. Numerical results for irregular waves show a clear dependence of the dissipation rate with the Ursell (Ur) parameter. The dissipation rate becomes sensitive to frequency spreading for Ur attenuation with respect to an f - 4 formulation. Finally, bispectral analysis of irregular wave propagation allow us to investigate the mechanism of wave attenuation. The numerical results suggest that energy is directly dissipated at the peak frequency, whereas nonlinear energy transfer plays an important role in energy attenuation at higher harmonics.

  5. Neglect severity after left and right brain damage.

    Science.gov (United States)

    Suchan, Julia; Rorden, Chris; Karnath, Hans-Otto

    2012-05-01

    While unilateral spatial neglect after left brain damage is undoubtedly less common than spatial neglect after a right hemisphere lesion, it is also assumed to be less severe. Here we directly test this latter hypothesis using a continuous measure of neglect severity: the so-called Center of Cancellation (CoC). Rorden and Karnath (2010) recently validated this index for right brain damaged neglect patients. A first aim of the present study was to evaluate this new measure for spatial neglect after left brain damage. In a group of 48 left-sided stroke patients with and without neglect, a score greater than -0.086 on the Bells Test and greater than -0.024 on the Letter Cancellation Task turned out to indicate neglect behavior for acute left brain damaged patients. A second aim was to directly compare the severity of spatial neglect after left versus right brain injury by using the new CoC measure. While neglect is less frequent following left than right hemisphere injury, we found that when this symptom occurs it is of similar severity in acute left brain injury as in patients after acute right brain injury. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. The prevention of circulatory collapse in left atrial myxoma or left atrail thrombus patients.

    Science.gov (United States)

    Sun, Jie; Ding, Zhengnian

    2016-05-01

    Some patients with myxoma or thrombus may develop to severe hypotension or sudden death. In this article, we hypothesize a clinical scenario that when the myxoma or thrombus blocks in the mitral valve and causes significant hypotension during anesthesia or surgery. Increasing cardiac preload will be an effective preventive method to increasing the mitral valve annulus and decreasing the severity of stenosis, as a result it will prevent circulatory collapse. Our hypothesis will decrease the possibility of lethal mitral valve stenosis induced by left atrial mass blocking the mitral valve area. In addition, we should also maintain a relative slow heart rate and a relative high systemic vascular resistance. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Hand Matters: Left-Hand Gestures Enhance Metaphor Explanation

    Science.gov (United States)

    2017-01-01

    Research suggests that speech-accompanying gestures influence cognitive processes, but it is not clear whether the gestural benefit is specific to the gesturing hand. Two experiments tested the “(right/left) hand-specificity” hypothesis for self-oriented functions of gestures: gestures with a particular hand enhance cognitive processes involving the hemisphere contralateral to the gesturing hand. Specifically, we tested whether left-hand gestures enhance metaphor explanation, which involves right-hemispheric processing. In Experiment 1, right-handers explained metaphorical phrases (e.g., “to spill the beans,” beans represent pieces of information). Participants kept the one hand (right, left) still while they were allowed to spontaneously gesture (or not) with their other free hand (left, right). Metaphor explanations were better when participants chose to gesture when their left hand was free than when they did not. An analogous effect of gesturing was not found when their right hand was free. In Experiment 2, different right-handers performed the same metaphor explanation task but, unlike Experiment 1, they were encouraged to gesture with their left or right hand or to not gesture at all. Metaphor explanations were better when participants gestured with their left hand than when they did not gesture, but the right hand gesture condition did not significantly differ from the no-gesture condition. Furthermore, we measured participants’ mouth asymmetry during additional verbal tasks to determine individual differences in the degree of right-hemispheric involvement in speech production. The left-over-right-side mouth dominance, indicating stronger right-hemispheric involvement, positively correlated with the left-over-right-hand gestural benefit on metaphor explanation. These converging findings supported the “hand-specificity” hypothesis. PMID:28080121

  8. Heart monitoring using left ventricle impedance and ventricular electrocardiography in left ventricular assist device patients.

    Science.gov (United States)

    Her, Keun; Ahn, Chi Bum; Park, Sung Min; Choi, Seong Wook

    2015-03-21

    Patients who develop critical arrhythmia during left ventricular assist device (LVAD) perfusion have a low survival rate. For diagnosis of unexpected heart abnormalities, new heart-monitoring methods are required for patients supported by LVAD perfusion. Ventricular electrocardiography using electrodes implanted in the ventricle to detect heart contractions is unsuitable if the heart is abnormal. Left ventricular impedance (LVI) is useful for monitoring heart movement but does not show abnormal action potential in the heart muscle. To detect detailed abnormal heart conditions, we obtained ventricular electrocardiograms (v-ECGs) and LVI simultaneously in porcine models connected to LVADs. In the porcine models, electrodes were set on the heart apex and ascending aorta for real-time measurements of v-ECGs and LVI. As the carrier current frequency of the LVI was adjusted to 30 kHz, it was easily derived from the original v-ECG signal by using a high-pass filter (cutoff: 10 kHz). In addition, v-ECGs with a frequency band of 0.1 - 120 Hz were easily derived using a low-pass filter. Simultaneous v-ECG and LVI data were compared to detect heart volume changes during the Q-T period when the heart contracted. A new real-time algorithm for comparison of v-ECGs and LVI determined whether the porcine heartbeats were normal or abnormal. Several abnormal heartbeats were detected using the LVADs operating in asynchronous mode, most of which were premature ventricle contractions (PVCs). To evaluate the accuracy of the new method, the results obtained were compared to normal ECG data and cardiac output measured simultaneously using commercial devices. The new method provided more accurate detection of abnormal heart movements. This method can be used for various heart diseases, even those in which the cardiac output is heavily affected by LVAD operation.

  9. Fatal stroke after completion pneumonectomy for torsion of left upper lobe following left lower lobectomy

    Directory of Open Access Journals (Sweden)

    Apostolakis Efstratios

    2006-09-01

    Full Text Available Abstract Background The lobar torsion after lung surgery is a rare complication with an incidence of 0.09 to 0.4 %. It may occur after twisting of the bronchovascular pedicle of the remaining lobe after lobectomy, usually on the right side. The 180-degree rotation of the pedicle produces an acute obstruction of the lobar bronchus (atelectasis and of the lobar vessels as well. Without prompt treatment it progresses to lobar ischemia, pulmonary infarction and finally fatal gangrene. Case Presentation A 62 years old female patient was admitted for surgical treatment of lung cancer. She underwent elective left lower lobectomy for squamous cell carcinoma (pT2 N0. The operation was unremarkable, and the patient was extubated in the operating room. After eight hours the patient established decrease of pO2 and chest x-ray showed atelectasis of the lower lobe. To establish diagnosis, bronchoscopy was performed, demonstrating obstructed left lobar bronchus. The patient was re-intubated, and admitted to the operating room where reopening of the thoracotomy was performed. Lobar torsion was diagnosed, with the diaphragmatic surface of the upper lobe facing in an anterosuperior orientation. A completion pneumonectomy was performed. At the end of the procedure the patient developed a right pupil dilatation, presumably due to a cerebral embolism. A subsequent brain angio-CT scan established the diagnosis. She died at the intensive care unit 26 days later. Conclusion The thoracic surgeon should suspect this rare early postoperative complication after any thoracic operation in every patient with atelectasis of the neighboring lobe. High index of suspicion and prompt diagnosis may prevent catastrophic consequences, such as, infarction or gangrene of the pulmonary lobe. During thoracic operations, especially whenever the lung or lobe hilum is full mobilized, fixation of the remaining lobe may prevent this life threatening complication.

  10. An Unusual Left Upper Quadrant Mass: A Bronchopulmonary Foregut Malformation

    Directory of Open Access Journals (Sweden)

    R. L. McDermott

    2013-01-01

    Full Text Available We report a case of a lady who presented with epigastric discomfort. Physical examination revealed a large left upper quadrant mass filling the left upper quadrant. Following extensive preoperative evaluation, she underwent resection of this centimeter mass with en bloc excision of a portion of the left hemidiaphragm. She made an uneventful postoperative recovery. Histopathology revealed a bronchopulmonary foregut malformation with pulmonary sequestration. This developmental anomaly of the foregut typically occurs in the thoracic cavity; however, it can occur below the diaphragm. Herein we report a case and a detailed review of the embryology, clinical features, and management of these extremely rare clinical entities.

  11. Left-sided gall bladder: Report of two cases

    Directory of Open Access Journals (Sweden)

    Chrungoo R

    2007-01-01

    Full Text Available Left-sided gall bladder without situs inversus viscerum is a rare albeit recognized clinical entity. We report our experience of two cases of left-sided gall bladder in two women aged 36 and 48 who underwent laparoscopic cholecystectomy for chronic calculous cholecystitis. Left-sided gall bladder may provide an unusual surprise to the surgeons during laparoscopy as routine pre-operative studies may not always detect the anomaly. Awareness of the unpredictable confluence of the cystic duct into the common bile duct (CBD and selective use of intraoperative cholangiography aid in the safe laparoscopic management of this unusual entity.

  12. An unusual variation of left ventricular-right atrial communication.

    Science.gov (United States)

    Komai, H; Naito, Y; Fujiwara, K; Takagaki, Y; Nishimura, Y; Kawasaki, S

    1996-01-01

    We herein present a 5-month-old boy with an infravalvular-type left ventricular-right atrial communication without an abnormal tricuspid valve leaflet. The thick chorda of the anterior tricuspid leaflet was inserted into the upper edge of the ventricular septal defect which was placed just under the commissure. The jet from the septal defect pushed this thick chorda and opened the commissure, which thus caused the abnormal pathway from the left ventricle to the right atrium. This mechanism of left ventricular-right atrial communication has not yet been reported elsewhere.

  13. EMC characteristics of composite structure - Electric/electromagnetic shielding attenuation

    Science.gov (United States)

    Wegertseder, P.; Breitsameter, R.

    1989-09-01

    The paper reports electric/electromagnetic shielding-attenuation experiments performed on different test boxes built with the same materials and processes as those to be used for the construction of a helicopter. The measurements are performed in the frequency range of 14 to 18 GHz, and the effects of different composite materials, jointing and bonding of structure parts of the boxes, application and bonding of the mesh, the construction of access panels, and conductive seals on these panels are assessed. It is demonstrated that moderate electric/electromagnetic shielding-attenuation values can be achieved by composite structures made from carbon, and materials and procedures required for high shielding attenuation are discussed.

  14. Cine CT for Attenuation Correction in Cardiac PET/CT

    Science.gov (United States)

    Alessio, Adam M.; Kohlmyer, Steve; Branch, Kelley; Chen, Grace; Caldwell, James; Kinahan, Paul

    2008-01-01

    In dual-modality PET/CT systems, the CT scan provides the attenuation map for PET attenuation correction. The current clinical practice of obtaining a single helical CT scan provides only a snapshot of the respiratory cycle, whereas PET occurs over multiple respiratory cycles. Misalignment of the attenuation map and emission image because of respiratory motion causes errors in the attenuation correction factors and artifacts in the attenuation-corrected PET image. To rectify this problem, we evaluated the use of cine CT, which acquires multiple low-dose CT images during a respiratory cycle. We evaluated the average and the intensity-maximum image of cine CT for cardiac PET attenuation correction. Methods Cine CT data and cardiac PET data were acquired from a cardiac phantom and from multiple patient studies. The conventional helical CT, cine CT, and PET data of an axially translating phantom were evaluated with and without respiratory motion. For the patient studies, we acquired 2 cine CT studies for each PET acquisition in a rest–stress 13N-ammonia protocol. Three readers visually evaluated the alignment of 74 attenuation image sets versus the corresponding emission image and determined whether the alignment provided acceptable or unacceptable attenuation-corrected PET images. Results In the phantom study, the attenuation correction from helical CT caused a major artifactual defect in the lateral wall on the PET image. The attenuation correction from the average and from the intensity-maximum cine CT images reduced the defect by 20% and 60%, respectively. In the patient studies, 77% of the cases using the average of the cine CT images had acceptable alignment and 88% of the cases using the intensity maximum of the cine CT images had acceptable alignment. Conclusion Cine CT offers an alternative to helical CT for compensating for respiratory motion in the attenuation correction of cardiac PET studies. Phantom studies suggest that the average and the intensity

  15. One hertz seismic attenuation for low frequency gravitational waves interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Mantovani, Maddalena [Universita di Siena Via Roma 56-53100 Siena (Italy)]. E-mail: mantovan@ego-gw.it; DeSalvo, Riccardo [California Institute of Technology 18-34, Pasadena, CA 91125 (United States)

    2005-12-01

    This article describes a mechanical vertical attenuation system capable to provide large attenuation factors above 1Hz. This system is derived from, and improves, the passive Geometric Anti-Spring seismic attenuation filters minimizing their vertical resonant frequency by means of a tunable electromagnetic spring mounted in parallel with the main spring. The tunable spring is also used to compensate thermal drift in the new arrangement. We found an unexplained deviation from the 1/f{sup 2} transfer function at resonant frequencies below {approx}100mHz.

  16. Photon attenuation properties of some thorium, uranium and plutonium compounds

    Energy Technology Data Exchange (ETDEWEB)

    Singh, V. P.; Badiger, N. M. [Karnatak University, Department of Physics, Dharwad-580003, Karnataka (India); Vega C, H. R., E-mail: kudphyvps@rediffmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2015-10-15

    Mass attenuation coefficients, effective atomic numbers, effective electron densities for nuclear materials; thorium, uranium and plutonium compounds have been studied. The photon attenuation properties for the compounds have been investigated for partial photon interaction processes by photoelectric effect, Compton scattering and pair production. The values of these parameters have been found to change with photon energy and interaction process. The variations of mass attenuation coefficients, effective atomic number and electron density with energy are shown graphically. Moreover, results have shown that these compounds are better shielding and suggesting smaller dimensions. The study would be useful for applications of these materials for gamma ray shielding requirement. (Author)

  17. Ultrasound attenuation estimation using backscattered echoes from multiple sources

    OpenAIRE

    Bigelow, Timothy A.

    2008-01-01

    The objective of this study was to devise an algorithm that can accurately estimate the attenuation along the propagation path (i.e., the total attenuation) from backscattered echoes. It was shown that the downshift in the center frequency of the backscattered ultrasound echoes compared to echoes obtained in a water bath was calculated to have the form Δf=mfo+b after normalizing with respect to the source bandwidth where m depends on the correlation length, b depends on the total attenuation,...

  18. Comparison of MR-based attenuation correction and CT-based attenuation correction of whole-body PET/MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo-Garcia, David [Mount Sinai School of Medicine, Translational and Molecular Imaging Institute, New York, NY (United States); Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA (United States); Sawiak, Stephen J. [University of Cambridge, Wolfson Brain Imaging Centre, Cambridge (United Kingdom); Knesaurek, Karin; Machac, Joseph [Mount Sinai School of Medicine, Division of Nuclear Medicine, Department of Radiology, New York, NY (United States); Narula, Jagat [Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); Fuster, Valentin [Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); The Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid (Spain); Fayad, Zahi A. [Mount Sinai School of Medicine, Translational and Molecular Imaging Institute, New York, NY (United States); Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); Mount Sinai School of Medicine, Department of Radiology, New York, NY (United States)

    2014-08-15

    The objective of this study was to evaluate the performance of the built-in MR-based attenuation correction (MRAC) included in the combined whole-body Ingenuity TF PET/MR scanner and compare it to the performance of CT-based attenuation correction (CTAC) as the gold standard. Included in the study were 26 patients who underwent clinical whole-body FDG PET/CT imaging and subsequently PET/MR imaging (mean delay 100 min). Patients were separated into two groups: the alpha group (14 patients) without MR coils during PET/MR imaging and the beta group (12 patients) with MR coils present (neurovascular, spine, cardiac and torso coils). All images were coregistered to the same space (PET/MR). The two PET images from PET/MR reconstructed using MRAC and CTAC were compared by voxel-based and region-based methods (with ten regions of interest, ROIs). Lesions were also compared by an experienced clinician. Body mass index and lung density showed significant differences between the alpha and beta groups. Right and left lung densities were also significantly different within each group. The percentage differences in uptake values using MRAC in relation to those using CTAC were greater in the beta group than in the alpha group (alpha group -0.2 ± 33.6 %, R{sup 2} = 0.98, p < 0.001; beta group 10.31 ± 69.86 %, R{sup 2} = 0.97, p < 0.001). In comparison to CTAC, MRAC led to underestimation of the PET values by less than 10 % on average, although some ROIs and lesions did differ by more (including the spine, lung and heart). The beta group (imaged with coils present) showed increased overall PET quantification as well as increased variability compared to the alpha group (imaged without coils). PET data reconstructed with MRAC and CTAC showed some differences, mostly in relation to air pockets, metallic implants and attenuation differences in large bone areas (such as the pelvis and spine) due to the segmentation limitation of the MRAC method. (orig.)

  19. Repeated sauna therapy attenuates ventricular remodeling after myocardial infarction in rats by increasing coronary vascularity of noninfarcted myocardium.

    Science.gov (United States)

    Sobajima, Mitsuo; Nozawa, Takashi; Shida, Takuya; Ohori, Takashi; Suzuki, Takayuki; Matsuki, Akira; Inoue, Hiroshi

    2011-08-01

    Repeated sauna therapy (ST) increases endothelial nitric oxide synthase (eNOS) activity and improves cardiac function in heart failure as well as peripheral blood flow in ischemic limbs. The present study investigates whether ST can increase coronary vascularity and thus attenuate cardiac remodeling after myocardial infarction (MI). We induced MI by ligating the left coronary artery of Wistar rats. The rats were placed in a far-infrared dry sauna at 41°C for 15 min and then at 34°C for 20 min once daily for 4 wk. Cardiac hemodynamic, histopathological, and gene analyses were performed. Despite the similar sizes of MI between the ST and non-ST groups (51.4 ± 0.3 vs. 51.1 ± 0.2%), ST reduced left ventricular (LV) end-diastolic (9.7 ± 0.4 vs. 10.7 ± 0.5 mm, P myocardial atrial natriuretic peptide mRNA levels. Vascular density was reduced in the noninfarcted myocardium of non-ST rats, and the density of cells positive for CD31 and for α-smooth muscle actin was decreased. These decreases were attenuated in ST rats compared with non-ST rats and associated with increases in myocardial eNOS and vascular endothelial growth factor mRNA levels. In conclusion, ST attenuates cardiac remodeling after MI, at least in part, through improving coronary vascularity in the noninfarcted myocardium. Repeated ST might serve as a novel noninvasive therapy for patients with MI.

  20. MRI-guided attenuation correction in whole-body PET/MR: assessment of the effect of bone attenuation.

    Science.gov (United States)

    Akbarzadeh, A; Ay, M R; Ahmadian, A; Alam, N Riahi; Zaidi, H

    2013-02-01

    Hybrid PET/MRI presents many advantages in comparison with its counterpart PET/CT in terms of improved soft-tissue contrast, decrease in radiation exposure, and truly simultaneous and multi-parametric imaging capabilities. However, the lack of well-established methodology for MR-based attenuation correction is hampering further development and wider acceptance of this technology. We assess the impact of ignoring bone attenuation and using different tissue classes for generation of the attenuation map on the accuracy of attenuation correction of PET data. This work was performed using simulation studies based on the XCAT phantom and clinical input data. For the latter, PET and CT images of patients were used as input for the analytic simulation model using realistic activity distributions where CT-based attenuation correction was utilized as reference for comparison. For both phantom and clinical studies, the reference attenuation map was classified into various numbers of tissue classes to produce three (air, soft tissue and lung), four (air, lungs, soft tissue and cortical bones) and five (air, lungs, soft tissue, cortical bones and spongeous bones) class attenuation maps. The phantom studies demonstrated that ignoring bone increases the relative error by up to 6.8% in the body and up to 31.0% for bony regions. Likewise, the simulated clinical studies showed that the mean relative error reached 15% for lesions located in the body and 30.7% for lesions located in bones, when neglecting bones. These results demonstrate an underestimation of about 30% of tracer uptake when neglecting bone, which in turn imposes substantial loss of quantitative accuracy for PET images produced by hybrid PET/MRI systems. Considering bones in the attenuation map will considerably improve the accuracy of MR-guided attenuation correction in hybrid PET/MR to enable quantitative PET imaging on hybrid PET/MR technologies.