QRS-fragmentation: Case report and review of the literature.

PubMed

Illescas-González, Edgar; Araiza-Garaygordobil, Diego; Sierra Lara, Jorge Daniel; Ramirez-Salazar, Aristoteles; Sierra-Fernández, Carlos; Alexanderson-Rosas, Erick

Fragmentation of QRS complex (QRSf) is an easily evaluable, non-invasive electrocardiographic parameter that represents depolarisation anomalies and has been associated with several adverse outcomes, such as sudden death, fibrosis, arrhythmic burden, and a worse prognosis in different conditions, including coronary artery disease (CAD). The case is presented of a 69-year old male referred due to symptoms of chronic stable angina. His electrocardiogram showed sinus rhythm, absence of Q waves, but the presence of QRSf in the inferior leads and V4-V6. A Tc-99 myocardial perfusion SPECT scan revealed a fixed perfusion defect in the inferolateral region, corresponding to the finding of QRSf. QRSf is an easily valuable electrocardiographic marker with relative sensitivity, but poor specificity. Its routine clinical application could contribute to an increase in the suspicion of coronary artery disease. The presence of fragmented QRS represents distortion of signal conduction and depolarisation, which is related to myocardial scar or myocardial fibrosis. Copyright © 2016 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

Prognostic value of biological markers in myocardial infarction patients.

PubMed

Berezin, Alexander E; Samura, Tatiana A

2013-04-01

The aim of this study was to compare the prognostic value of matrix metalloproteinase-3 and -9, and NT-pro-natriuretic peptide for fatal and nonfatal complications in Q-wave myocardial infarction patients in the acute and postinfarction periods. 85 men and women with documented Q-wave myocardial infarction were observed for 1 year after hospitalization. Clinical endpoints were identified through the hospital patient-tracking system, with a review of medical records for each recorded endpoint. Left ventricular ejection fraction and wall motion index were calculated. Measurements of matrix metalloproteinases and NT-pro-natriuretic peptide were performed by an enzyme-linked immunosorbent assay. A cutoff value of 9.7 ng·mL(-1) for matrix metalloproteinase-3 showed the best discriminatory power (sensitivity = 77.8%, specificity = 90.8%). The optimal cutoff value of matrix metalloproteinase-9 was 18.1 ng·mL(-1) (sensitivity, 70.5%; specificity, 75%), and the cutoff for NT-pro-natriuretic peptide was 885 pmol·L(-1) (sensitivity, 58%; specificity, 68.6%). Matrix metalloproteinase-3 and -9 were strongly related with a positive prognostic value of 70% (sensitivity and specificity, 84% and 82%, respectively). These data may be helpful for further stratification of patients into cardiovascular mortality risk groups.

[Anomalous origin of the left coronary artery from the pulmonary trunk with myocardial infarction and severe left ventricular dysfunction in infancy--assessment of myocardial damage using SPECT studies with 201TlCl and 123I-BMIPP].

PubMed

Miyamoto, T; Horigome, H; Sato, H; Yamada, M; Inai, K; Takeda, T; Ishikawa, N; Hoshino, H; Itai, Y

1996-02-01

A 4-month-old male infant with Bland-White-Garland (BWG) syndrome complicated myocardial infarction was reported. Signs included tachypnea, coughing, and failure to thrive. However, there was no sign of myocardial infarction. A chest radiograph revealed cardiomegaly (CTR = 65%) and electrocardiogram showed abnormal Q waves in I, aVL, V6 leads. Cardiac catheterization and angiography revealed marked dilatation of left ventricle (end-diastolic volume = 384 ml/m2) and extremely depressed ejection fraction (16%), confirming the diagnosis of BWG syndrome. A 201TlCl-myocardial SPECT demonstrated apical defect and hypoperfusion in the anterolateral, inferoposterior walls, whereas 123I-beta-methyl-p-iodophenylpentadecanoic-acid (123I-BMIPP) SPECT showed a wider defect area. SPECT studies with 201TlCl and 123I-BMIPP, are useful to assess myocardial viability more accurately in BWG syndrome.

T wave abnormalities, high body mass index, current smoking and high lipoprotein (a) levels predict the development of major abnormal Q/QS patterns 20 years later. A population-based study

PubMed Central

Moller, Christina Strom; Byberg, Liisa; Sundstrom, Johan; Lind, Lars

2006-01-01

Background Most studies on risk factors for development of coronary heart disease (CHD) have been based on the clinical outcome of CHD. Our aim was to identify factors that could predict the development of ECG markers of CHD, such as abnormal Q/QS patterns, ST segment depression and T wave abnormalities, in 70-year-old men, irrespective of clinical outcome. Methods Predictors for development of different ECG abnormalities were identified in a population-based study using stepwise logistic regression. Anthropometrical and metabolic factors, ECG abnormalities and vital signs from a health survey of men at age 50 were related to ECG abnormalities identified in the same cohort 20 years later. Results At the age of 70, 9% had developed a major abnormal Q/QS pattern, but 63% of these subjects had not been previously hospitalized due to MI, while 57% with symptomatic MI between age 50 and 70 had no major Q/QS pattern at age 70. T wave abnormalities (Odds ratio 3.11, 95% CI 1.18–8.17), high lipoprotein (a) levels, high body mass index (BMI) and smoking were identified as significant independent predictors for the development of abnormal major Q/QS patterns. T wave abnormalities and high fasting glucose levels were significant independent predictors for the development of ST segment depression without abnormal Q/QS pattern. Conclusion T wave abnormalities on resting ECG should be given special attention and correlated with clinical information. Risk factors for major Q/QS patterns need not be the same as traditional risk factors for clinically recognized CHD. High lipoprotein (a) levels may be a stronger risk factor for silent myocardial infarction (MI) compared to clinically recognized MI. PMID:16519804

Epstein-Barr virus myocarditis as the first symptom of infectious mononucleosis.

PubMed

Zabala López, Sergio; Vicario, Juana M; Lerín, Francisco J; Fernández, Amalia; Pérez, Gloria; Fonseca, Cherpentier

2010-01-01

This case report describes a 20-year-old immunocompetent man with an episode of chest pain radiating into both arms, an increase in the level of myocardial enzymes, electrocardiogram abnormalities (widespread ST-segment elevation and q waves in leads V(4)-V(6)) and serological evidence for acute Epstein-Barr Virus infection preceding typical signs and symptoms of infectious mononucleosis.

Declining case fatality rates for acute myocardial infarction in South Asian and white patients in the past 15 years.

PubMed

Liew, R; Sulfi, S; Ranjadayalan, K; Cooper, J; Timmis, A D

2006-08-01

To determine whether case fatality rates in South Asian (Bangladeshi, Indian and Pakistani) patients with acute myocardial infarction have shown similar declines to those reported for white patients during the past 15 years. Cross-sectional, observational study. Coronary care unit in east London. 2640 patients-29% South Asian-admitted with acute myocardial infarction between January 1988 and December 2002. Differences over time in rates of in-hospital death, ventricular fibrillation and left ventricular failure. The proportion of South Asians increased from 22% in 1988-92 to 37% in 1998-2002. Indices of infarct severity were similar in South Asian and white patients, with declining frequencies of ST elevation infarction (88.2% to 77.5%, p < 0.0001), Q wave development (78.1% to 56.9%, p < 0.0001) and mean (interquartile range) peak serum creatine kinase concentrations (1250 (567-2078) to 1007 (538-1758) IU/l, p < 0.0001) between 1988-92 and 1998-2002. Rates of in-hospital death (13.0% to 9.4%, p < 0.01), ventricular fibrillation (9.2% to 6.0%, p < 0.001) and left ventricular failure (33.2% to 26.5%, p < 0.0001) all declined; these changes did not interact significantly with ethnicity. Odds ratios for the effect of time on risk of death increased from 0.81 (95% CI 0.70 to 0.93) to 1.02 (95% CI 0.87 to 1.21) after adjustment for ethnicity and indices of infarct severity (ST elevation, peak creatine kinase, Q wave development and treatment with a thrombolytic). In the past 15 years, death from acute myocardial infarction among South Asians has declined at a rate similar to that seen in white patients. This is largely caused by reductions in indices of infarct severity.

Comparison of the QRS Complex, ST-Segment, and T-Wave Among Patients with Left Bundle Branch Block with and without Acute Myocardial Infarction.

PubMed

Dodd, Kenneth W; Elm, Kendra D; Smith, Stephen W

2016-07-01

The modified Sgarbossa criteria have been validated as a rule for diagnosis of acute coronary occlusion (ACO) in left bundle branch block (LBBB). However, no analysis has been done on differences in the QRS complex, T-wave, or ST-segment concordance of < 1 mm in the derivation or validation studies. Furthermore, there was no comparison of patients with acute myocardial infarction (AMI) but without ACO (i.e., non-ST-elevation myocardial infarction [non-STEMI]) to patients with ACO or without AMI (no MI). We compare findings involving the QRS amplitude, ST-segment morphology, ST-concordance < 1 mm, and T-waves in patients with LBBB with ACO, non-STEMI, and no MI. Retrospectively, emergency department patients were identified with LBBB and ischemic symptoms but no MI, with angiographically proven ACO, and with non-STEMI. ACO, non-STEMI, and no MI groups consisted of 33, 24, and 105 patients. The sum of the maximum deflection of the QRS amplitude across all leads (ΣQRS) was smaller in patients with ACO than those without ACO (101.5 mm vs. 132.5 mm; p < 0.0001) and a cutoff of ΣQRS < 90 mm was 92% specific. For ACO, non-concave ST-segment morphology was 91% specific, any ST concordance ≥ 1 mm was 95% specific, and any ST concordance ≥ 0.5 mm was 94% sensitive. For non-STEMI, terminal T-wave concordance, analogous to biphasic T-waves, was moderately sensitive at 79%. We found differences in QRS amplitude, ST-segment morphology, and T-waves between patients with LBBB and ACO, non-STEMI, and no MI. However, none of these criteria outperformed the modified Sgarbossa criteria for diagnosis of ACO in LBBB. Copyright © 2016 Elsevier Inc. All rights reserved.

The number of unrecognized myocardial infarction scars detected at DE-MRI increases during a 5-year follow-up.

PubMed

Themudo, Raquel; Johansson, Lars; Ebeling-Barbier, Charlotte; Lind, Lars; Ahlström, Håkan; Bjerner, Tomas

2017-02-01

In an elderly population, the prevalence of unrecognized myocardial infarction (UMI) scars found via late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging was more frequent than expected. This study investigated whether UMI scars detected with LGE-CMR at age 70 would be detectable at age 75 and whether the scar size changed over time. From 248 participants that underwent LGE-CMR at age 70, 185 subjects underwent a follow-up scan at age 75. A myocardial infarction (MI) scar was defined as late enhancement involving the subendocardium. In the 185 subjects that underwent follow-up, 42 subjects had a UMI scar at age 70 and 61 subjects had a UMI scar at age 75. Thirty-seven (88 %) of the 42 UMI scars seen at age 70 were seen in the same myocardial segment at age 75. The size of UMI scars did not differ between age 70 and 75. The prevalence of UMI scars detected at LGE-CMR increases with age. During a 5-year follow-up, 88 % (37/42) of the UMI scars were visible in the same myocardial segment, reassuring that UMI scars are a consistent finding. The size of UMI scars detected during LGE-CMR did not change over time. • UMI scars detected by LGE-CMR are frequent in elderly. • The prevalence of UMI scars detected with LGE-CMR increases with age. • UMI scar size does not change over time.

Diagnostic contribution of cardiac magnetic resonance in patients with acute coronary syndrome and culprit-free angiograms.

PubMed

Kawecki, Damian; Morawiec, Beata; Monney, Pierre; Pellaton, Cyril; Wojciechowska, Celina; Jojko, Joanna; Basiak, Marcin; Przywara-Chowaniec, Brygida; Fournier, Stephane; Nowalany-Kozielska, Ewa; Schwitter, Juerg; Muller, Olivier

2015-01-14

In spite of robust knowledge about underlying ischemic myocardial damage, acute coronary syndromes (ACS) with culprit-free angiograms raise diagnostic concerns. The present study aimed to evaluate the additional value of cardiac magnetic resonance (CMR) over commonly available non-CMR standard tests, for the differentiation of myocardial injury in patients with ACS and non-obstructed coronary arteries. Patients with ACS, elevated hs-TnT, and a culprit-free angiogram were prospectively enrolled into the study between January 2009 and July 2013. After initial evaluation with standard tests (ECG, echocardiography, hs-TnT) and provisional exclusion of acute myocardial infarction (AMI) in coronary angiogram, patients were referred for CMR with the suspicion of myocarditis or Takotsubo cardiomyopathy (TTC). According to the result of CMR, patients were reclassified as having myocarditis, AMI, TTC, or non-injured myocardium as assessed by late gadolinium enhancement. Out of 5110 patients admitted with ACS, 75 had normal coronary angiograms and entered the study; 69 of them (92%) were suspected for myocarditis and 6 (8%) for TTC. After CMR, 49 patients were finally diagnosed with myocarditis (65%), 3 with TTC (4%), 7 with AMI (9%), and 16 (21%) with non-injured myocardium. The provisional diagnosis was changed or excluded in 23 patients (31%), with a 9% rate of unrecognized AMI. The study results suggest that the evaluation of patients with ACS and culprit-free angiogram should be complemented by a CMR examination, if available, because the initial work-up with non-CMR tests leads to a significant proportion of misdiagnosed AMI.

Economics, health-related quality of life, and cost-effectiveness methods for the TACTICS (Treat Angina With Aggrastat [tirofiban

PubMed

Weintraub, W S; Culler, S D; Kosinski, A; Becker, E R; Mahoney, E; Burnette, J; Spertus, J A; Feeny, D; Cohen, D J; Krumholz, H; Ellis, S G; Demopoulos, L; Robertson, D; Boccuzzi, S J; Barr, E; Cannon, C P

1999-02-01

Concern over escalating health care costs has led to increasing focus on economics and assessment of outcome measures for expensive forms of therapy. This is being investigated in the Treat Angina With Aggrastat [tirofiban] and Determine Cost of Therapy with Invasive or Conservative Strategy (TACTICS)-TIMI 18 trial, a randomized trial comparing outcome of patients with unstable angina or non-Q-wave myocardial infarction treated with tirofiban and then randomized to an invasive versus a conservative strategy. Hospital and professional costs initially and over 6 months, including outpatient costs, will be assessed. Hospital costs will be determined for patients in the United States from the UB92 formulation of the hospital bill, with costs derived from charges using departmental cost to charge ratios. Professional costs will be determined by accounting for professional services and then converted to resource units using the Resource Based Relative Value Scale and then to costs using the Medicare conversion factor. Follow-up resource consumption, including medications, testing and office visits, will be carefully measured with a Patient Economic Form, and converted to costs from the Medicare fee schedule. Health-related quality of life will be assessed with a specific instrument, the Seattle Angina Questionnaire, and a general instrument, the Health Utilities Index at baseline, 1, and 6 months. The Health Utilities Index will also be used to construct a utility. By knowing utility and survival, quality-adjusted life years will be determined. These measures will permit the performance of a cost-effectiveness analysis, with the cost-effectiveness of the invasive strategy defined and the difference in cost between the invasive and conservative strategies divided by the difference in quality-adjusted life years. The economic and health-related quality of life aspects of TACTICS-TIMI 18 are an integral part of the study design and will provide a comprehensive understanding of the impact of invasive versus conservative management strategies on a broad range of outcomes after hospitalization for unstable angina or non-Q-wave myocardial infarction.

Prognostic impact of terminal T wave inversions on presentation in patients with ST-elevation myocardial infarction undergoing urgent percutaneous coronary intervention.

PubMed

Shimada, Yuichi J; Po, Jose Ricardo F; Kanei, Yumiko; Schweitzer, Paul

2013-01-01

Terminal T wave inversions (TTWI) indicate advanced stages of ST-elevation myocardial infarction (STEMI). The present study investigated whether TTWI predict unfavorable in-hospital outcomes in STEMI patients treated with urgent percutaneous coronary intervention (PCI). A retrospective cohort study was performed with consecutive 188 STEMI cases undergoing urgent PCI. The primary endpoint was in-hospital major adverse cardiac event (MACE), and the secondary endpoints were ST resolution (STR) after PCI and length of stay (LOS). TTWI on presentation were independently associated with higher incidence of in-hospital MACE (adjusted OR 2.8; 95% CI 1.1-7.0; p=0.03), inadequate STR (adjusted OR 5.5; 95% CI 2.1-14.3; p=0.01), and longer LOS (adjusted mean increase 4.1 days; 95% CI 0.3-7.9; p=0.03). TTWI predicted these outcomes better than patient-reported ischemic time or pathologic Q waves. TTWI on presentation are an independent risk factor for poor inpatient prognosis among patients presenting with STEMI undergoing urgent PCI. Copyright © 2013 Elsevier Inc. All rights reserved.

Myocardial uptake and kinetic properties of technetium-99m-Q3 in dogs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerson, M.C.; Millard, R.W.; McGoron, A.J.

1994-10-01

We postulated that {sup 99m}Tc-Q3, a cationic imaging agent, produces myocardial activity related to myocardial blood flow during myocardial ischemia and pharmacologic coronary artery vasodilation, and shows little or no myocardial redistribution over 4 hr after intravenous injection. In six Group 1 dogs, the chest was opened, the left circumflex coronary artery was acutely ligated, and dipyridamole (0.32, 0.56 or 0.84 mg/kg) was infused into the right atrium, followed by 10 mCi of {sup 99m}Tc-Q3. Myocardial blood flow was measured by radiolabeled microspheres. The animals were euthanized and 357 myocardial samples were assayed in a well counter for {sup 99m}Tcmore » activity. One week later, radiolabeled microsphere activity was counted and myocardial blood flow calculated. In nine Group 2 dogs, a variable occluder was placed around the left circumflex coronary artery and an ischemic level of circumflex blood flow was maintained constant over 4 hr as measured by an ultrasonic flow meter. Dipyridamole (0.56 mg/kg) was then infused into the right atrium followed by 10mCi of {sup 99m}Tc-Q3. Gamma camera images were acquired at 5, 15, 30, 60, 120 and 240 min following k{sup 99m}Tc-Q3 injection. Microsphere blood flow and endocardial biopsies (n - 6 dogs) were performed at 30, 60, 120 and 240 min following {sup 99m}TcQ3 injection. 31 refs., 9 figs., 1 tab.« less

Increased beat-to-beat T-wave variability in myocardial infarction patients.

PubMed

Hasan, Muhammad A; Abbott, Derek; Baumert, Mathias; Krishnan, Sridhar

2018-03-28

The purpose of this study was to investigate the beat-to-beat variability of T-waves (TWV) and to assess the diagnostic capabilities of T-wave-based features for myocardial infarction (MI). A total of 148 recordings of standard 12-lead electrocardiograms (ECGs) from 79 MI patients (22 females, mean age 63±12 years; 57 males, mean age 57±10 years) and 69 recordings from healthy subjects (HS) (17 females, 42±18 years; 52 males, 40±13 years) were studied. For the quantification of beat-to-beat QT intervals in ECG signal, a template-matching algorithm was applied. To study the T-waves beat-to-beat, we measured the angle between T-wave max and T-wave end with respect to Q-wave (∠α) and T-wave amplitudes. We computed the standard deviation (SD) of beat-to-beat T-wave features and QT intervals as markers of variability in T-waves and QT intervals, respectively, for both patients and HS. Moreover, we investigated the differences in the studied features based on gender and age for both groups. Significantly increased TWV and QT interval variability (QTV) were found in MI patients compared to HS (p<0.05). No significant differences were observed based on gender or age. TWV may have some diagnostic attributes that may facilitate identifying patients with MI. In addition, the proposed beat-to-beat angle variability was found to be independent of heart rate variations. Moreover, the proposed feature seems to have higher sensitivity than previously reported feature (QT interval and T-wave amplitude) variability for identifying patients with MI.

It's a trap! Clinical similarities and subtle ECG differences between takotsubo cardiomyopathy and myocardial infarction.

PubMed

Vivo, Rey P; Krim, Selim R; Hodgson, John

2008-11-01

We describe a 65-year-old woman with a history of hypertension and smoking who presented with an acute episode of chest pain precipitated by severe emotional stress. Her initial electrocardiogram done in the emergency room showed non-specific T wave changes in the lateral leads and her cardiac troponin levels were mildly elevated. Because of her clinical presentation, she was admitted with a presumptive diagnosis of acute myocardial infarction and managed with antiplatelet and anticoagulant therapy. Coronary angiogram did not reveal coronary artery disease and left ventriculography showed findings consistent with apical ballooning syndrome or takotsubo cardiomyopathy. Subsequent electrocardiograms displayed dramatic changes including T wave inversions, QT interval prolongation and U waves. The patient remained asymptomatic and recovered uneventfully. Three weeks post-discharge, an echocardiogram documented resolved left ventricular dysfunction. We describe the clinical features and highlight the electrocardiographic findings that may help differentiate takotsubo cardiomyopathy from myocardial infarction.

Non-ST elevation myocardial infarction secondary to carbon monoxide intoxication

PubMed Central

Jankowska, Danuta; Palabindala, Venkataraman; Salim, Sohail Abdul

2017-01-01

ABSTRACT Carbon monoxide poisoning has been documented in literature to cause severe neurological and tissue toxicity within the body. However, cardiotoxicity is often overlooked, but not uncommon. Previous research studies and case reports have revealed a significant relationship between carbon monoxide intoxication and myocardial ischemic events. We report a case of a 48-year-old male, who was exposed to severe smoke inhalation due to a house fire and subsequently developed a non-ST elevation myocardial infarction. Ischemic changes were evident on electrocardiogram, which demonstrated T-wave inversion in lead III and ST-segment depression in leads V4-V6. Elevated cardiac enzymes were also present. After standard treatment for an acute cardiac event, the patient fully recovered. This case demonstrates that myocardial ischemic changes due to carbon monoxide poisoning may be reversible if recognized in early stages and treated appropriately, thus reminding physicians that a proper cardiovascular examination and diagnostic testing should be performed on all patients with carbon monoxide poisoning. Abbreviations: NSTEMI: Non-ST elevation myocardial infarction PMID:28638579

Measurement of acute Q-wave myocardial infarct size with single photon emission computed tomography imaging of indium-111 antimyosin.

PubMed

Antunes, M L; Seldin, D W; Wall, R M; Johnson, L L

1989-04-01

Myocardial infarct size was measured by single photon emission computed tomography (SPECT) following injection of indium-111 antimyosin in 27 patients (18 male and 9 female; mean age 57.4 +/- 10.5 years, range 37 to 75) who had acute transmural myocardial infarction (MI). These 27 patients represent 27 of 35 (77%) consecutive patients with acute Q-wave infarctions who were injected with indium-111 antimyosin. In the remaining 8 patients either tracer uptake was too faint or the scans were technically inadequate to permit infarct sizing from SPECT reconstructions. In the 27 patients studied, infarct location by electrocardiogram was anterior in 15 and inferoposterior in 12. Nine patients had a history of prior infarction. Each patient received 2 mCi of indium-111 antimyosin followed by SPECT imaging 48 hours later. Infarct mass was determined from coronal slices using a threshold value obtained from a human torso/cardiac phantom. Infarct size ranged from 11 to 87 g mean 48.5 +/- 24). Anterior infarcts were significantly (p less than 0.01) larger (60 +/- 20 g) than inferoposterior infarcts (34 +/- 21 g). For patients without prior MI, there were significant inverse correlations between infarct size and ejection fraction (r = 0.71, p less than 0.01) and wall motion score (r = 0.58, p less than 0.01) obtained from predischarge gated blood pool scans. Peak creatine kinase-MB correlated significantly with infarct size for patients without either reperfusion or right ventricular infarction (r = 0.66). Seven patients without prior infarcts had additional simultaneous indium-111/thallium-201 SPECT studies using dual energy windows.(ABSTRACT TRUNCATED AT 250 WORDS)

Infarct size in primary angioplasty without on-site cardiac surgical backup versus transferal to a tertiary center: a single photon emission computed tomography study.

PubMed

Knaapen, Paul; de Mulder, Maarten; van der Zant, Friso M; Peels, Hans O; Twisk, Jos W R; van Rossum, Albert C; Cornel, Jan H; Umans, Victor A W M

2009-02-01

Primary percutaneous coronary intervention (PCI) performed in large community hospitals without cardiac surgery back-up facilities (off-site) reduces door-to-balloon time compared with emergency transferal to tertiary interventional centers (on-site). The present study was performed to explore whether off-site PCI for acute myocardial infarction results in reduced infarct size. One hundred twenty-eight patients with acute ST-segment elevation myocardial infarction were randomly assigned to undergo primary PCI at the off-site center (n = 68) or to transferal to an on-site center (n = 60). Three days after PCI, (99m)Tc-sestamibi SPECT was performed to estimate infarct size. Off-site PCI significantly reduced door-to-balloon time compared with on-site PCI (94 +/- 54 versus 125 +/- 59 min, respectively, p < 0.01), although symptoms-to-treatment time was only insignificantly reduced (257 +/- 211 versus 286 +/- 146 min, respectively, p = 0.39). Infarct size was comparable between treatment centers (16 +/- 15 versus 14 +/- 12%, respectively p = 0.35). Multivariate analysis revealed that TIMI 0/1 flow grade at initial coronary angiography (OR 3.125, 95% CI 1.17-8.33, p = 0.023), anterior wall localization of the myocardial infarction (OR 3.44, 95% CI 1.38-8.55, p < 0.01), and development of pathological Q-waves (OR 5.07, 95% CI 2.10-12.25, p < 0.01) were independent predictors of an infarct size > 12%. Off-site PCI reduces door-to-balloon time compared with transferal to a remote on-site interventional center but does not reduce infarct size. Instead, pre-PCI TIMI 0/1 flow, anterior wall infarct localization, and development of Q-waves are more important predictors of infarct size.

Compressive and rarefactive double layers in non-uniform plasma with q-nonextensive distributed electrons

NASA Astrophysics Data System (ADS)

Shan, S. Ali; Saleem, H.

2018-05-01

Electrostatic solitary waves and double layers (DLs) formed by the coupled ion acoustic (IA) and drift waves have been investigated in non-uniform plasma using q-nonextensive distribution function for the electrons and assuming ions to be cold Ti< Te. It is found that both compressive and rarefactive nonlinear structures (solitary waves and DLs) are possible in such a system. The steeper gradients are supportive for compressive solitary (and double layers) and destructive for rarefactive ones. The q-nonextensivity parameter q and the magnitudes of gradient scale lengths of density and temperature have significant effects on the amplitude of the double layers (and double layers) as well as on the speed of these structures. This theoretical model is general which has been applied here to the F-region ionosphere for illustration.

Defibrotide reduces infarct size in a rabbit model of experimental myocardial ischaemia and reperfusion.

PubMed Central

Thiemermann, C.; Thomas, G. R.; Vane, J. R.

1989-01-01

1. Defibrotide, a single-stranded polydeoxyribonucleotide obtained from bovine lungs, has significant anti-thrombotic, pro-fibrinolytic and prostacyclin-stimulating properties. 2. The present study was designed to evaluate the effects of defibrotide on infarct size and regional myocardial blood flow in a rabbit model of myocardial ischaemia and reperfusion. 3. Defibrotide (32 mg kg-1 bolus + 32 mg kg-1 h-1, i.v.) either with or without co-administration of indomethacin (5 mg kg-1 x 2, i.v.) was administered 5 min after occlusion of the left anterior-lateral coronary artery and continued during the 60 min occlusion and subsequent 3 h reperfusion periods. 4. Defibrotide significantly attenuated the ischaemia-induced ST-segment elevation and abolished the reperfusion-related changes (R-wave reduction and Q-wave development) in the electrocardiogram. In addition, defibrotide significantly improved myocardial blood flow in normal and in ischaemic, but not in infarcted sections of the heart. The improvement in blood flow in normal perfused myocardium, but not in the ischaemic area was prevented by indomethacin. 5. Although the area at risk was similar in all animal groups studied, defibrotide treatment resulted in a 51% reduction of infarct size. Indomethacin treatment abolished the reduction of infarct size seen with defibrotide alone. 6. The data demonstrate a considerable cardioprotective effect of defibrotide in the reperfused ischaemic rabbit myocardium. This effect may be related, at least in part, to a stimulation of endogenous prostaglandin formation. Other possible mechanisms are discussed. PMID:2758223

Elevated troponin I levels in acute liver failure: is myocardial injury an integral part of acute liver failure?

PubMed

Parekh, Nimisha K; Hynan, Linda S; De Lemos, James; Lee, William M

2007-06-01

Although rare instances of cardiac injury or arrhythmias have been reported in acute liver failure (ALF), overall, the heart is considered to be spared in this condition. Troponin I, a sensitive and specific marker of myocardial injury, may be elevated in patients with sepsis and acute stroke without underlying acute coronary syndrome, indicating unrecognized cardiac injury in these settings. We sought to determine whether subclinical cardiac injury might also occur in acute liver failure. Serum troponin I levels were measured in 187 patients enrolled in the US Acute Liver Failure Study Group registry, and correlated with clinical variables and outcomes. Diagnoses were representative of the larger group of >1000 patients thus far enrolled and included 80 with acetaminophen-related injury, 26 with viral hepatitis, 19 with ischemic injury, and 62 others. Overall, 74% of patients had elevated troponin I levels (>0.1 ng/ml). Patients with elevated troponin I levels were more likely to have advanced hepatic coma (grades III or IV) or to die (for troponin I levels >0.1 ng/ml, odds ratio 3.88 and 4.69 for advanced coma or death, respectively). In acute liver failure, subclinical myocardial injury appears to occur more commonly than has been recognized, and its pathogenesis in the context of acute liver failure is unclear. Elevated troponin levels are associated with a significant increase in morbidity and mortality. Measurement of troponin I levels may be helpful in patients with acute liver failure, to detect unrecognized myocardial damage and as a marker of unfavorable outcome.

Phonon self-energy corrections to non-zero wavevector phonon modes in single-layer graphene

NASA Astrophysics Data System (ADS)

Araujo, Paulo; Mafra, Daniela; Sato, Kentaro; Saito, Richiiro; Kong, Jing; Dresselhaus, Mildred

2012-02-01

Phonon self-energy corrections have mostly been studied theoretically and experimentally for phonon modes with zone-center (q = 0) wave-vectors. Here, gate-modulated Raman scattering is used to study phonons of a single layer of graphene (1LG) in the frequency range from 2350 to 2750 cm-1, which shows the G* and the G'-band features originating from a double-resonant Raman process with q 0. The observed phonon renormalization effects are different from what is observed for the zone-center q = 0 case. To explain our experimental findings, we explored the phonon self-energy for the phonons with non-zero wave-vectors (q 0) in 1LG in which the frequencies and decay widths are expected to behave oppositely to the behavior observed in the corresponding zone-center q = 0 processes. Within this framework, we resolve the identification of the phonon modes contributing to the G* Raman feature at 2450 cm-1 to include the iTO+LA combination modes with q 0 and the 2iTO overtone modes with q = 0, showing both to be associated with wave-vectors near the high symmetry point K in the Brillouin zone.

Coronary wave energy: a novel predictor of functional recovery after myocardial infarction.

PubMed

De Silva, Kalpa; Foster, Paul; Guilcher, Antoine; Bandara, Asela; Jogiya, Roy; Lockie, Tim; Chowiencyzk, Phil; Nagel, Eike; Marber, Michael; Redwood, Simon; Plein, Sven; Perera, Divaka

2013-04-01

Revascularization after acute coronary syndromes provides prognostic benefit, provided that the subtended myocardium is viable. The microcirculation and contractility of the subtended myocardium affect propagation of coronary flow, which can be characterized by wave intensity analysis. The study objective was to determine in acute coronary syndromes whether early wave intensity analysis-derived microcirculatory (backward) expansion wave energy predicts late viability, defined by functional recovery. Thirty-one patients (58±11 years) were enrolled after non-ST elevation myocardial infarction. Regional left ventricular function and late-gadolinium enhancement were assessed by cardiac magnetic resonance imaging, before and 3 months after revascularization. The backward-traveling (microcirculatory) expansion wave was derived from wave intensity analysis of phasic coronary pressure and velocity in the infarct-related artery, whereas mean values were used to calculate hyperemic microvascular resistance. Twelve-hour troponin T, left ventricular ejection fraction, and percentage late-gadolinium enhancement mass were 1.35±1.21 µg/L, 56±11%, and 8.4±6.0%, respectively. The infarct-related artery backward-traveling (microcirculatory) expansion wave was inversely correlated with late-gadolinium enhancement infarct mass (r=-0.81; P<0.0001) and strongly predicted regional left ventricular recovery (r=0.68; P=0.001). By receiver operating characteristic analysis, a backward-traveling (microcirculatory) expansion wave threshold of 2.8 W m(-2) s(-2)×10(5) predicted functional recovery with sensitivity and specificity of 0.91 and 0.82 (AUC 0.88). Hyperemic microvascular resistance correlated with late-gadolinium enhancement mass (r=0.48; P=0.03) but not left ventricular recovery (r=-0.34; P=0.07). The microcirculation-derived backward expansion wave is a new index that correlates with the magnitude and location of infarction, which may allow for the prediction of functional myocardial recovery. Coronary wave intensity analysis may facilitate myocardial viability assessment during cardiac catheterization.

Coenzyme Q10 protects ischemic myocardium in an open-chest swine model.

PubMed

Atar, D; Mortensen, S A; Flachs, H; Herzog, W R

1993-01-01

Myocardial stunning, defined as a reversible decrease in contractility after ischemia and reperfusion, may be a manifestation of reperfusion injury caused by free oxygen radical damage. The aim of this study was to test the hypothesis that pretreatment with coenzyme Q10 (ubiquinone), believed to act as a free radical scavenger, reduces myocardial stunning in a porcine model. Twelve swine were randomized to receive either oral supplementation with coenzyme Q10 or placebo for 20 days. A normothermic open-chest model was used with short occlusion (8 min) of the distal left descending coronary artery followed by reperfusion. Regional contractile function was measured with epicardial Doppler crystals in ischemic and nonischemic segments by measuring thickening fraction of the left ventricular wall during systole. Stunning time was defined as the elapsed time of reduced contractility until return to baseline. Coenzyme Q10 concentrations were measured in blood and homogenized myocardial tissue by high performance liquid chromatography. Plasma levels of reduced coenzyme Q10 (ubiquinol) were higher in swine pretreated with the experimental medication as compared to placebo (mean 0.45 mg/l versus 0.11 mg/l, respectively). Myocardial tissue concentrations, however, did not show any changes (mean 0.79 micrograms/mg dry weight versus 0.74 micrograms/mg). Stunning time was significantly reduced in coenzyme Q10 pretreated animals (13.7 +/- 7.7 min versus 32.8 +/- 3.1 min, P < 0.01). In conclusion, chronic pretreatment with coenzyme Q10 protects ischemic myocardium in an open-chest swine model. The beneficial effect of coenzyme Q10 on myocardial stunning may be due to protection from free radical mediated reperfusion injury. This protective effect seems to be generated by a humoral rather than intracellular mechanism.

Cardioprotective medication use and risk factor control among US adults with unrecognized myocardial infarction: the REasons for Geographic And Racial Differences in Stroke (REGARDS) study

PubMed Central

Levitan, Emily B; Gamboa, Christopher; Safford, Monika M; Rizk, Dana V; Brown, Todd M; Soliman, Elsayed Z; Muntner, Paul

2013-01-01

Background Individuals with unrecognized myocardial infarction (UMI) have similar risks for cardiovascular events and mortality as those with recognized myocardial infarction (RMI). The prevalence of cardioprotective medication use and blood pressure and low-density lipoprotein cholesterol control among individuals with UMI is unknown. Methods Participants from the REasons for Geographic And Racial Differences in Stroke (REGARDS) study who were recruited between May 2004 and October 2007 received baseline twelve-lead electrocardiograms (n = 21,036). Myocardial infarction (MI) status was characterized as no MI, UMI (electrocardiogram abnormalities consistent with MI without self-reported history; n = 949; 4.5%), and RMI (self-reported history of MI; n = 1574; 7.5%). Results For participants with no MI, UMI, and RMI, prevalence of use was 38.4%, 44.4%, and 75.7% for aspirin; 18.0%, 25.8%, and 57.2% for beta blockers; 31.7%, 38.7%, and 55.0% for angiotensin converting enzyme inhibitors or angiotensin receptor blockers; and 28.1%, 33.9%, and 64.1% for statins, respectively. Participants with RMI were 35% more likely to have low-density lipoprotein cholesterol < 100 mg/dL than participants with UMI (prevalence ratio = 1.35, 95% confidence interval 1.19–1.52). Blood pressure control (,140/90 mmHg) was similar between RMI and UMI groups (prevalence ratio = 1.03, 95% confidence interval 0.93–1.13). Conclusion Although participants with UMI were somewhat more likely to use cardioprotective medications than those with no MI, they were less likely to use cardioprotective medications and to have controlled low-density lipoprotein cholesterol than participants with RMI. Increasing appropriate treatment and risk factor control among individuals with UMI may reduce risk of mortality and future cardiovascular events. PMID:23404361

The long-term risk of recognized and unrecognized myocardial infarction for depression in older men.

PubMed

Jovanova, O; Luik, A I; Leening, M J G; Noordam, R; Aarts, N; Hofman, A; Franco, O H; Dehghan, A; Tiemeier, H

2016-07-01

The association between myocardial infarction (MI) and depression is well described. Yet, the underlying mechanisms are unclear and the contribution of psychological factors is uncertain. We aimed to determine the risk of recognized (RMI) and unrecognized (UMI) myocardial infections on depression, as both have a similar impact on cardiovascular health but differ in psychological epiphenomena. Participants of the Rotterdam Study, 1823 men aged ⩾55 years, were followed for the occurrence of depression. RMI and UMI were ascertained using electrocardiography and medical history at baseline. We determined the strength of the association of RMI and UMI with mortality, and we studied the relationship of RMI and UMI with depressive symptoms and the occurrence of major depression. The risk of mortality was similar in men with RMI [adjusted hazard ratio (aHR) 1.71, 95% confidence interval (CI) 1.45-2.03] and UMI (aHR 1.58, 95% CI 1.27-1.97). Men with RMI had on average [unstandardized regression coefficient (B) 1.14, 95% CI 0.07-2.21] higher scores for depressive symptoms. By contrast, we found no clear association between UMI and depressive symptoms (B 0.55, 95% CI -0.51 to 1.62) in men. Analysis including occurrence of major depression as the outcome were consistent with the pattern of association. The discrepant association of RMI and UMI with mortality compared to depression suggests that the psychological burden of having experienced an MI contributes to the long-term risk of depression.

Development of Extracorporeal Shock Wave Therapy for the Treatment for Ischemic Cardiovascular Diseases

NASA Astrophysics Data System (ADS)

Shimokawa, Hiroaki

Cardiovascular diseases, such as coronary artery disease and peripheral artery disease, are the major causes of death in developed countries, and the number of elderly patients has been rapidly increasing worldwide. Thus, it is crucial to develop new non-invasive therapeutic strategies for these patients. We found that a low-energy shock wave (SW) (about 10% of the energy density that is used for urolithiasis) effectively increases the expression of vascular endothelial growth factor (VEGF) in cultured endothelial cells. Subsequently, we demonstrated that extracorporeal cardiac SW therapy with low-energy SW up-regulates the expression of VEGF, enhances angiogenesis, and improves myocardial ischemia in a pig model of chronic myocardial ischemia without any adverse effects in vivo. Based on these promising results in animal studies, we have subsequently developed a new, non-invasive angiogenic therapy with low-energy SW for cardiovascular diseases. Our extracorporeal cardiac SW therapy improved symptoms and myocardial perfusion evaluated with stress-scintigraphy in patients with severe coronary artery disease without indication of percutaneous coronary intervention or coronary artery bypass surgery. Importantly, no procedural complications or adverse effects were noted. The SW therapy was also effective in ameliorating left ventricular remodeling after acute myocardial infarction in pigs and in enhancing angiogenesis in hindlimb ischemia in animals and patients with coronary artery disease. Furthermore, our recent experimental studies suggest that the SW therapy is also effective for indications other than cardiovascular diseases. Thus, our extracorporeal cardiac SW therapy is an effective, safe, and non-invasive angiogenic strategy for cardiovascular medicine.

Is Seismically Determined Q an Intrinsic Material Property?

NASA Astrophysics Data System (ADS)

Langston, C. A.

2003-12-01

The seismic quality factor, Q, has a well-defined physical meaning as an intrinsic material property associated with a visco-elastic or a non-linear stress-strain constitutive relation for a material. Measurement of Q from seismic waves, however, involves interpreting seismic wave amplitude and phase as deviations from some ideal elastic wave propagation model. Thus, assumptions in the elastic wave propagation model become the basis for attributing anelastic properties to the earth continuum. Scientifically, the resulting Q model derived from seismic data is no more than a hypothesis that needs to be verified by other independent experiments concerning the continuum constitutive law and through careful examination of the truth of the assumptions in the wave propagation model. A case in point concerns the anelasticity of Mississippi embayment sediments in the central U.S. that has important implications for evaluation of earthquake strong ground motions. Previous body wave analyses using converted Sp phases have suggested that Qs is ~30 in the sediments based on simple ray theory assumptions. However, detailed modeling of 1D heterogeneity in the sediments shows that Qs cannot be resolved by the Sp data. An independent experiment concerning the amplitude decay of surface waves propagating in the sediments shows that Qs must be generally greater than 80 but is also subject to scattering attenuation. Apparent Q effects seen in direct P and S waves can also be produced by wave tunneling mechanisms in relatively simple 1D heterogeneity. Heterogeneity is a general geophysical attribute of the earth as shown by many high-resolution data sets and should be used as the first litmus test on assumptions made in seismic Q studies before a Q model can be interpreted as an intrinsic material property.

[Electrocardiographic differences between apical hypertrophic cardiomyopathy and apical non-ST segment myocardial infarction].

PubMed

Chillik, Iván; Gil Ramírez, Andreina; Ordóñez, Santiago; Tomás, Leandro; Parodi, Josefina; Costabel, Juan Pablo

2018-01-01

Apocal hypertrophic cardiomyopathy (AHCM) is a phenotypic variant within hypertrophic cardiomyopathies, in which ventricular repolarization alterations are present. These electrocardiographic disturbances can mimic an anterior infarction which triggers a series of studies and treatments that may be unnecessary. The aim of this study was to describe and compare electrocardiographic differences in a series of patients with AHCM and apical non-ST segment elevation myocardial infarction in patients (NSTEMI) with T-wave changes. We conducted an observational and retrospective study, including patients with diagnosed AHCM (N = 19) and apical NSTEMI (N = 19) with negative T waves in V1 and V6 lead of the EKG. Those with AHCM presented higher T-wave voltage (7 mV vs. 5 mV, p = 0.001) and peak voltage (29 mV vs. 17 mV, p = 0.003), higher R-waves (25 mV vs. 10 mV, p = 0.0001), and a maximum voltage of R and T sum (R + T) significantly higher (33 vs. 14, p = 0.00001). They also showed a greater T-wave asymmetry, with a TiTp / TpTf ratio > 1. At a cut-off value of 26.5 mV for the R + T variable, 68% sensitivity and 100% specificity were obtained to diagnose AHCM. This study shows the existence of major differences in electrocardiographic presentation of AHCM and apical NSTEMI.

Effect of PlA1/A2 glycoprotein IIIa gene polymorphism on the long-term outcome after successful coronary stenting

PubMed Central

Le Hello, Claire; Morello, Rémy; Lequerrec, Agnès; Duarte, Christine; Riddell, John; Hamon, Martial

2007-01-01

Aim To prospectively determine the role of platelet glycoprotein IIIa (GP IIIa) gene PlA1/PlA2 polymorphism on the long-term clinical outcome in patients with coronary artery disease undergoing coronary stenting. Design and setting Prospective observational study in the University Hospital of Caen (France). Patients and methods 1 111 symptomatic consecutive Caucasian patients treated with percutaneous coronary intervention including stent implantation underwent genotyping for GP IIIa PlA1/A2. Main outcome measures Long-term clinical outcome in terms of the rate of major adverse cardiac events (MACE, ie death from any cause, non-fatal Q wave or non Q wave myocardial infarction, and need for coronary revascularisation) was obtained and subsequently stratified according to the GP IIIa PlA1/A2 polymorphism. Results Three groups of patients were determined according to the GP IIIa PlA1/A2 polymorphism (71.6% had the A1/A1, 25.8% had the A1/A2 and 2.6% had the A2/A2 genotype). These three groups were comparable for all clinical characteristics including sex ratio, mean age, vascular risk factors, previous coronary events, baseline angiographic exam, indication for the percutaneous coronary intervention and drug therapy). The incidence of MACE was similar in these 3 groups of patients during a mean follow-up period of 654+/-152 days. Independent risk factors for MACE were a left ventricular ejection fraction < 40%, absence of treatment with a beta-blocker and absence of treatment with an angiotensin converting enzyme inhibitor during follow-up. Conclusion The GP IIIa PlA1/A2 polymorphism does not influence the clinical long-term outcome in patients with symptomatic coronary disease undergoing percutaneous coronary intervention with stent implantation. PMID:18021403

Assessment tools for unrecognized myocardial infarction: a cross-sectional analysis of the REasons for geographic and racial differences in stroke population

PubMed Central

2013-01-01

Background Routine electrocardiograms (ECGs) are not recommended for asymptomatic patients because the potential harms are thought to outweigh any benefits. Assessment tools to identify high risk individuals may improve the harm versus benefit profile of screening ECGs. In particular, people with unrecognized myocardial infarction (UMI) have elevated risk for cardiovascular events and death. Methods Using logistic regression, we developed a basic assessment tool among 16,653 participants in the REasons for Geographic and Racial Differences in Stroke (REGARDS) study using demographics, self-reported medical history, blood pressure, and body mass index and an expanded assessment tool using information on 51 potential variables. UMI was defined as electrocardiogram evidence of myocardial infarction without a self-reported history (n = 740). Results The basic assessment tool had a c-statistic of 0.638 (95% confidence interval 0.617 - 0.659) and included age, race, smoking status, body mass index, systolic blood pressure, and self-reported history of transient ischemic attack, deep vein thrombosis, falls, diabetes, and hypertension. A predicted probability of UMI > 3% provided a sensitivity of 80% and a specificity of 30%. The expanded assessment tool had a c-statistic of 0.654 (95% confidence interval 0.634-0.674). Because of the poor performance of these assessment tools, external validation was not pursued. Conclusions Despite examining a large number of potential correlates of UMI, the assessment tools did not provide a high level of discrimination. These data suggest defining groups with high prevalence of UMI for targeted screening will be difficult. PMID:23530553

Dynamical susceptibility near a long-wavelength critical point with a nonconserved order parameter

NASA Astrophysics Data System (ADS)

Klein, Avraham; Lederer, Samuel; Chowdhury, Debanjan; Berg, Erez; Chubukov, Andrey

2018-04-01

We study the dynamic response of a two-dimensional system of itinerant fermions in the vicinity of a uniform (Q =0 ) Ising nematic quantum critical point of d - wave symmetry. The nematic order parameter is not a conserved quantity, and this permits a nonzero value of the fermionic polarization in the d - wave channel even for vanishing momentum and finite frequency: Π (q =0 ,Ωm)≠0 . For weak coupling between the fermions and the nematic order parameter (i.e., the coupling is small compared to the Fermi energy), we perturbatively compute Π (q =0 ,Ωm)≠0 over a parametrically broad range of frequencies where the fermionic self-energy Σ (ω ) is irrelevant, and use Eliashberg theory to compute Π (q =0 ,Ωm) in the non-Fermi-liquid regime at smaller frequencies, where Σ (ω )>ω . We find that Π (q =0 ,Ω ) is a constant, plus a frequency-dependent correction that goes as |Ω | at high frequencies, crossing over to |Ω| 1 /3 at lower frequencies. The |Ω| 1 /3 scaling holds also in a non-Fermi-liquid regime. The nonvanishing of Π (q =0 ,Ω ) gives rise to additional structure in the imaginary part of the nematic susceptibility χ″(q ,Ω ) at Ω >vFq , in marked contrast to the behavior of the susceptibility for a conserved order parameter. This additional structure may be detected in Raman scattering experiments in the d - wave geometry.

[Prevalence of metabolic syndrome components in patients with acute coronary syndromes].

PubMed

Zaliūnas, Remigijus; Slapikas, Rimvydas; Luksiene, Dalia; Slapikiene, Birute; Statkeviciene, Audrone; Milvidaite, Irena; Gustiene, Olivija

2008-01-01

Many studies report that the components of the metabolic syndrome--arterial hypertension, abdominal obesity, diabetes mellitus, and atherogenic dyslipidemia--are associated with an increased risk of cardiovascular disease. We investigated the prevalence of different components of the metabolic syndrome and frequency of their combinations and acute hyperglycemia among patients with acute coronary syndromes. The study population consisted of 2756 patients (1670 men and 1086 women with a mean age of 63.3+/-11.3 years) with acute coronary syndromes: Q-wave myocardial infarction was present in 41.8% of patients; non-Q-wave MI, in 30.7%; and unstable angina pectoris, in 27.5%. The metabolic syndrome was found in 59.6% of the patients according to modified NCEP III guidelines. One component of the metabolic syndrome was found in 13.5% of patients; two, in 23.0%; and none, in 3.9%. Less than one-third (29.2%) of the patients had three components of the metabolic syndrome, and 30.4% of the patients had four or five components. Arterial hypertension and abdominal obesity were the most common components of the metabolic syndrome (82.2% and 65.8%, respectively). Nearly half of the patients had hypertriglyceridemia and decreased level of high-density lipoprotein cholesterol (55.0% and 51.1%, respectively), and 23.9% of patients had diabetes mellitus. Acute hyperglycemia (> or =6.1 mmol/L) without known diabetes mellitus was found in 38.1% of cases. The combination of arterial hypertension and abdominal obesity was reported in 57.8% of patients in the case of combinations of two-five metabolic syndrome components. More than half of patients with acute coronary syndromes had three or more components of the metabolic syndrome, and arterial hypertension and abdominal obesity were the most prevalent components of the metabolic syndrome.

Atypical patterns of cardiac involvement in Fabry disease.

PubMed

Coughlan, J J; Elkholy, K; O'Brien, J; Kiernan, T

2016-03-17

A 58-year-old woman was referred to our cardiology service with chest pain, exertional dyspnoea and palpitations on a background of known Fabry disease diagnosed with genetic testing in 1994. ECG showed sinus rhythm, shortened PR interval, widespread t wave inversion, q waves in the lateral leads and left ventricular hypertrophy (LVH). Coronary angiogram showed only mild atheroma. Transthoracic echocardiogram showed anterolateral LVH and reduced left ventricular cavity size in keeping with Fabry cardiomyopathy. Cardiac MRI demonstrated asymmetric hypertrophy with evidence of diffuse myocardial fibrosis in the maximally hypertrophied segments from base to apex with late gadolinium enhancement in the anterior and anteroseptal walls. This was quite an atypical appearance for Fabry cardiomyopathy. This case highlights the heterogeneity of patterns of cardiac involvement that may be associated with this rare X-linked lysosomal disorder. 2016 BMJ Publishing Group Ltd.

The potential role of myocardial serotonin receptor 2B expression in canine dilated cardiomyopathy.

PubMed

Fonfara, Sonja; Hetzel, Udo; Oyama, Mark A; Kipar, Anja

2014-03-01

Serotonin signalling in the heart is mediated by receptor subtype 2B (5-HTR2B). A contribution of serotonin to valvular disease has been reported, but myocardial expression of 5-HTR2B and its role in canine dilated cardiomyopathy (DCM) is not known. The aim of the present study was to investigate myocardial 5-HTR2B mRNA expression in dogs with DCM and to correlate results with expression of markers for inflammation and remodelling. Myocardial samples from eight healthy dogs, four dogs with DCM, five with cardiac diseases other than DCM and six with systemic non-cardiac diseases were investigated for 5-HTR2B mRNA expression using quantitative PCR (qPCR). The results were compared to mRNA expression of selected cytokines, matrix metalloproteinases (MMP) and tissue inhibitors of matrix metalloproteinase (TIMP). Laser microdissection with subsequent qPCR and immunohistochemistry were employed to identify the cells expressing 5-HTR2B. The myocardium of control dogs showed constitutive 5-HTR2B mRNA expression. In dogs with DCM, 5-HTR2B mRNA values were significantly greater than in all other groups, with highest levels of expression in the left ventricle and right atrium. Myocytes were identified as the source of 5-HTR2B mRNA and protein. A significant positive correlation of 5-HTR2B mRNA with expression of several cytokines, MMPs and TIMPs was observed. The findings suggest that serotonin might play a role in normal cardiac structure and function and could contribute to myocardial remodelling and functional impairment in dogs with DCM. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of a hydrophilic and a hydrophobic statin on cardiac salvage after ST-elevated acute myocardial infarction - a pilot study.

PubMed

Chitose, Tadasuke; Sugiyama, Seigo; Sakamoto, Kenji; Shimomura, Hideki; Yamashita, Takuro; Hokamaki, Jun; Tsunoda, Ryusuke; Shiraishi, Shinya; Yamashita, Yasuyuki; Ogawa, Hisao

2014-11-01

Early statin therapy after acute coronary syndrome reduces atherothrombotic vascular events. This study aimed to compare the effects of hydrophilic and hydrophobic statins on myocardial salvage and left ventricular (LV) function in patients with ST-elevated myocardial infarction (STEMI). Seventy-five STEMI patients who had received emergency reperfusion therapy were enrolled and randomized into the hydrophilic statin group (rosuvastatin; 5 mg/day, n = 38) and hydrophobic statin group (atorvastatin; 10 mg/day, n = 37) for 6 months. LV ejection fraction (LVEF), and B-type natriuretic peptide (BNP) and co-enzyme Q10 (CoQ10) levels were measured at baseline and the end of treatment. The myocardial salvage index was assessed by single photon emission computed tomography with (123-)I-β-methyl-iodophenylpentadecanoic acid (ischemic area-at-risk at onset of STEMI: AAR) and (201-)thallium scintigraphy (area-at-infarction at 6 months: AAI) [myocardial salvage index = (AAR-AAI) × 100/AAR (%)]. Onset-to-balloon time and maximum creatine phosphokinase levels were comparable between the groups. After 6 months, rosuvastatin (-37.6% ± 17.2%) and atorvastatin (-32.4% ± 22.4%) equally reduced low-density lipoprotein-cholesterol (LDL-C) levels (p = 0.28). However, rosuvastatin (+3.1% ± 5.9%, p < 0.05), but not atorvastatin (+1.6% ± 5.7%, p = 0.15), improved LVEF. Rosuvastatin reduced BNP levels compared with atorvastatin (-53.3% ± 48.8% versus -13.8% ± 82.9%, p < 0.05). The myocardial salvage index was significantly higher in the rosuvastatin group than the atorvastatin group (78.6% ± 29.1% versus 52.5% ± 38.0%, p < 0.05). CoQ10/LDL-C levels at 6 months were increased in the rosuvastatin group (+23.5%, p < 0.01) and percent changes in CoQ10/LDL-C were correlated with the myocardial salvage index (r = 0.56, p < 0.01). Rosuvastatin shows better beneficial effects on myocardial salvage than atorvastatin in STEMI patients, including long-term cardiac function, associated with increasing CoQ10/LDL-C. URL http://www.umin.ac.jp/ctr/index.htm Unique Identifier: UMIN000003893. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Intra-QT spectral coherence as a possible noninvasive marker of sustained ventricular tachycardia.

PubMed

Piccirillo, Gianfranco; Moscucci, Federica; Persi, Alessandro; Di Barba, Daniele; Pappadà, Maria Antonella; Rossi, Pietro; Quaglione, Raffaele; Nguyen, Bich Lien; Barillà, Francesco; Casenghi, Matteo; Magrì, Damiano

2014-01-01

Sudden cardiac death is the main cause of mortality in patients affected by chronic heart failure (CHF) and with history of myocardial infarction. No study yet investigated the intra-QT phase spectral coherence as a possible tool in stratifying the arrhythmic susceptibility in patients at risk of sudden cardiac death (SCD). We, therefore, assessed possible difference in spectral coherence between the ECG segment extending from the q wave to the T wave peak (QTp) and the one from T wave peak to the T wave end (Te) between patients with and without Holter ECG-documented sustained ventricular tachycardia (VT). None of the QT variability indexes as well as most of the coherences and RR power spectral variables significantly differed between the two groups except for the QTp-Te spectral coherence. The latter was significantly lower in patients with sustained VT than in those without (0.508 ± 0.150 versus 0.607 ± 0.150, P < 0.05). Although the responsible mechanism remains conjectural, the QTp-Te spectral coherence holds promise as a noninvasive marker predicting malignant ventricular arrhythmias.

Intra-QT Spectral Coherence as a Possible Noninvasive Marker of Sustained Ventricular Tachycardia

PubMed Central

Piccirillo, Gianfranco; Moscucci, Federica; Di Barba, Daniele; Pappadà, Maria Antonella; Rossi, Pietro; Quaglione, Raffaele; Barillà, Francesco; Magrì, Damiano

2014-01-01

Sudden cardiac death is the main cause of mortality in patients affected by chronic heart failure (CHF) and with history of myocardial infarction. No study yet investigated the intra-QT phase spectral coherence as a possible tool in stratifying the arrhythmic susceptibility in patients at risk of sudden cardiac death (SCD). We, therefore, assessed possible difference in spectral coherence between the ECG segment extending from the q wave to the T wave peak (QTp) and the one from T wave peak to the T wave end (T e) between patients with and without Holter ECG-documented sustained ventricular tachycardia (VT). None of the QT variability indexes as well as most of the coherences and RR power spectral variables significantly differed between the two groups except for the QTp-T e spectral coherence. The latter was significantly lower in patients with sustained VT than in those without (0.508 ± 0.150 versus 0.607 ± 0.150, P < 0.05). Although the responsible mechanism remains conjectural, the QTp-T e spectral coherence holds promise as a noninvasive marker predicting malignant ventricular arrhythmias. PMID:25133170

Magnesium in cardioplegia: Is it necessary?

PubMed Central

Shakerinia, Tooraj; Ali, Idris M.; Sullivan, John A.P.

1996-01-01

Objective To study the effectiveness of magnesium in cardioplegic solution in preventing postoperative arrhythmias and perioperative ischemia. Design Randomized, control study. Setting The cardiovascular surgery division of a major referral centre for the maritime provinces of Canada. Patients Fifty patients scheduled to undergo coronary artery bypass who had a normal ejection fraction, normal preoperative serum magnesium level and no history of atrial or ventricular arrhythmia were randomized into two groups of 25 patients. One group received magnesium sulfate (15 mmol/L) in the cardioplegic solution (group 1), the other (control) group did not receive magnesium sulfate in the cardioplegic solution (group 2). Intervention Coronary artery bypass grafting during which myocardial protection was provided by intermittent cold blood cardioplegia. Outcome Measures Postoperative serum magnesium levels, cardiac-related death, infarction and arrhythmias. Results All group 2 patients had a lower postoperative serum magnesium level than group 1 patients. There were no cardiac-related deaths in either group. More group 2 patients had ischemic electrocardiographic changes than group 1 patients (p < 0.03). Non-Q-wave myocardial infarction occurred in two patients (one in each group). Eight patients in group 2 had atrial fibrillation compared with five patients in group 1. Ventricular ectopia occurred significantly (p < 0.01) more frequently in group 2 than in group 1. Conclusion The addition of magnesium to the cardioplegic solution is beneficial in reducing the incidence of perioperative ischemia and ventricular arrhythmia in patients who undergo coronary bypass grafting. PMID:8857989

Clinical utility of a two-site immunoradiometric assay for creatine kinase-MB in the detection of perioperative myocardial infarction

DOE Office of Scientific and Technical Information (OSTI.GOV)

DePuey, E.G.; Aessopos, A.; Monroe, L.R.

1983-08-01

In 144 patients, creatine kinase MB was measured serially at 0, 8, 16, 24, 48 and 72 h using a two-site immunoradionmetric assay (IRMA). Cardiac enzymes were also measured, including SGOT, LDH, total CPK, and CK-MB by electrophoresis. The presence of perioperative myocardial infarction (poMI) was established in 24 patients by the appearance of new electrocardiographic Q waves and/or new wall motion abnormalities detected by radionuclide ventriculography. In patients without poMI, CK-MB (IRMA) was elevated at 0 to 8 h but decreased by 16 h. In patients with poMI, peak values occurred at 16 to 24 h. Using a thresholdmore » value of 8.5 EU/I, patients with poMI could be distinguished from those without with 97% accuracy (sensitivity = 88%, specificity = 99%). We conclude that the CK-MB (IRMA) can serve as a valuable postoperative screening tet for poMI.« less

Myocardial protection with prophylactic oral metoprolol during coronary artery bypass grafting surgery: evaluation by troponin I

PubMed Central

Rossi Neto, João Manoel; Gun, Carlos; Ramos, Rui Fernando; de Almeida, Antonio Flavio Sanchez; Issa, Mario; Amato, Vivian Lener; Dinkhuysen, Jarbas J.; Piegas, Leopoldo Soares

2013-01-01

Introduction Biochemical markers of myocardial injury are frequently altered after cardiac surgery. So far there is no evidence whether oral beta-blockers may reduce myocardial injury after coronary artery bypass grafting. Objective To determine if oral administration of prophylactic metoprolol reduces the release of cardiac troponin I in isolated coronary artery bypass grafting, not complicated by new Q waves. Methods A prospective randomized study, including 68 patients, divided in 2 groups: Group A (n=33, control) and B (n=35, beta-blockers). In group B, metoprolol tartrate was administered 200 mg/day. The myocardial injury was assessed by troponin I with 1 hour and 12 hours after coronary artery bypass grafting. Results No significant difference between groups regarding pre-surgical, surgical, complication in intensive care (15% versus 14%, P=0.92) and the total number of hospital events (21% versus 14%, P=0.45) was observed. The median value of troponin I with 12 hours in the study population was 3.3 ng/ml and was lower in group B than in group A (2.5 ng/ml versus 3.7 ng/ml, P<0,05). In the multivariate analysis, the variables that have shown to be independent predictors of troponin I release after 12 hours were: no beta-blockers administration and number of vessels treated. Conclusion The results of this study in uncomplicated coronary artery bypass grafting, comparing the postoperative release of troponin I at 12 hours between the control group and who used oral prophylactic metoprolol for at least 72 hours, allow to conclude that there was less myocardial injury in the betablocker group, giving some degree of myocardial protection. PMID:24598948

Small amplitude two dimensional electrostatic excitations in a magnetized dusty plasma with q-distributed electrons

NASA Astrophysics Data System (ADS)

Khan, Shahab Ullah; Adnan, Muhammad; Qamar, Anisa; Mahmood, Shahzad

2016-07-01

The propagation of linear and nonlinear electrostatic waves is investigated in magnetized dusty plasma with stationary negatively or positively charged dust, cold mobile ions and non-extensive electrons. Two normal modes are predicted in the linear regime, whose characteristics are investigated parametrically, focusing on the effect of electrons non-extensivity, dust charge polarity, concentration of dust and magnetic field strength. Using the reductive perturbation technique, a Zakharov-Kuznetsov (ZK) type equation is derived which governs the dynamics of small-amplitude solitary waves in magnetized dusty plasma. The properties of the solitary wave structures are analyzed numerically with the system parameters i.e. electrons non-extensivity, concentration of dust, polarity of dust and magnetic field strength. Following Allen and Rowlands (J. Plasma Phys. 53:63, 1995), we have shown that the pulse soliton solution of the ZK equation is unstable, and have analytically traced the dependence of the instability growth rate on the nonextensive parameter q for electrons, dust charge polarity and magnetic field strength. The results should be useful for understanding the nonlinear propagation of DIA solitary waves in laboratory and space plasmas.

A generalized two-fluid picture of non-driven collisionless reconnection and its relation to whistler waves

DOE PAGES

None, None

2017-05-05

A generalized, intuitive two-fluid picture of 2D non-driven collisionless magnetic reconnection is described using results from a full-3D numerical simulation. The relevant two-fluid equations simplify to the condition that the flux associated with canonical circulation Q=m e∇×u e+q eB is perfectly frozen into the electron fluid. In the reconnection geometry, flux tubes defined by Q are convected with the central electron current, effectively stretching the tubes and increasing the magnitude of Q exponentially. This, coupled with the fact that Q is a sum of two quantities, explains how the magnetic fields in the reconnection region reconnect and give rise tomore » strong electron acceleration. The Q motion provides an interpretation for other phenomena as well, such as spiked central electron current filaments. The simulated reconnection rate was found to agree with a previous analytical calculation having the same geometry. Energy analysis shows that the magnetic energy is converted and propagated mainly in the form of the Poynting flux, and helicity analysis shows that the canonical helicity ∫P·Q dV as a whole must be considered when analyzing reconnection. A mechanism for whistler wave generation and propagation is also described, with comparisons to recent spacecraft observations.« less

Indexes of temporal myocardial repolarization dispersion and sudden cardiac death in heart failure: any difference?

PubMed

Piccirillo, Gianfranco; Rossi, Pietro; Mitra, Marilena; Quaglione, Raffaele; Dell'Armi, Annalaura; Di Barba, Daniele; Maisto, Damiana; Lizio, Andrea; Barillà, Francesco; Magrì, Damiano

2013-03-01

The QT variability index, calculated between Q- and the T-wave end (QTend VI), is an index of temporal myocardial repolarization lability associated with sudden cardiac death (SCD) in chronic heart failure (CHF). Little is known about temporal variability in the other two temporal myocardial repolarization descriptors obtained from Q-Tpeak and Tpeak -Tend intervals. We therefore investigated differences between these indexes in patients with CHF who died suddenly and in those who survived with a left ventricular ejection fraction (LVEF) ≤35% or >35%. We selected 127 ECG and systolic blood pressure (SPB) recordings from outpatients with CHF all of whom had been followed up for 30 months. We calculated RR and SPB variability by power spectral analysis and QTend VI, QTpeak VI, Tpeak Tend VI. We then subdivided data patients into three groups SCD, LVEF ≤ 35%, and LVEF > 35%. The LVEF was higher in the SCD than in the LVEF ≤ 35% group, whereas no difference was found between the SCD and LVEF > 35% groups. QTend VI, QTpeak VI, and Tpeak Tend VI were higher in the SCD and LVEF ≤ 35% groups than in the LVEF > 35% group. Multivariate analysis detected a negative relationship between all repolarization variability indexes, low frequency obtained from RR intervals and LVEF. Our data show that variability in the first (QTpeak VI) and second halves of the QT interval (Tpeak -Tend VI) significantly contributes to the QTend VI in patients with CHF. Further studies should investigate whether these indexes might help stratify the risk of SCD in patients with a moderately depressed LVEF. ©2012, Wiley Periodicals, Inc.

Ultrasound elastic tensor imaging: comparison with MR diffusion tensor imaging in the myocardium

NASA Astrophysics Data System (ADS)

Lee, Wei-Ning; Larrat, Benoît; Pernot, Mathieu; Tanter, Mickaël

2012-08-01

We have previously proven the feasibility of ultrasound-based shear wave imaging (SWI) to non-invasively characterize myocardial fiber orientation in both in vitro porcine and in vivo ovine hearts. The SWI-estimated results were in good correlation with histology. In this study, we proposed a new and robust fiber angle estimation method through a tensor-based approach for SWI, coined together as elastic tensor imaging (ETI), and compared it with magnetic resonance diffusion tensor imaging (DTI), a current gold standard and extensively reported non-invasive imaging technique for mapping fiber architecture. Fresh porcine (n = 5) and ovine (n = 5) myocardial samples (20 × 20 × 30 mm3) were studied. ETI was firstly performed to generate shear waves and to acquire the wave events at ultrafast frame rate (8000 fps). A 2.8 MHz phased array probe (pitch = 0.28 mm), connected to a prototype ultrasound scanner, was mounted on a customized MRI-compatible rotation device, which allowed both the rotation of the probe from -90° to 90° at 5° increments and co-registration between two imaging modalities. Transmural shear wave speed at all propagation directions realized was firstly estimated. The fiber angles were determined from the shear wave speed map using the least-squares method and eigen decomposition. The test myocardial sample together with the rotation device was then placed inside a 7T MRI scanner. Diffusion was encoded in six directions. A total of 270 diffusion-weighted images (b = 1000 s mm-2, FOV = 30 mm, matrix size = 60 × 64, TR = 6 s, TE = 19 ms, 24 averages) and 45 B0 images were acquired in 14 h 30 min. The fiber structure was analyzed by the fiber-tracking module in software, MedINRIA. The fiber orientation in the overlapped myocardial region which both ETI and DTI accessed was therefore compared, thanks to the co-registered imaging system. Results from all ten samples showed good correlation (r2 = 0.81, p < 0.0001) and good agreement (3.05° bias) between ETI and DTI fiber angle estimates. The average ETI-estimated fractional anisotropy (FA) values decreased from subendocardium to subepicardium (p < 0.05, unpaired, one-tailed t-test, N = 10) by 33%, whereas the corresponding DTI-estimated FA values presented a change of -10% (p > 0.05, unpaired, one-tailed t-test, N = 10). In conclusion, we have demonstrated that the fiber orientation estimated by ETI, which assesses the shear wave speed (and thus the stiffness), was comparable to that measured by DTI, which evaluates the preferred direction of water diffusion, and have validated this concept within the myocardium. Moreover, ETI was shown capable of mapping the transmural fiber angles with as few as seven shear wave propagation directions.

Temporal Trends in the Prevalence, Severity, and Localization of Myocardial Ischemia and Necrosis at Myocardial Perfusion Imaging After Myocardial Infarction.

PubMed

Nudi, Francesco; Schillaci, Orazio; Di Belardino, Natale; Versaci, Francesco; Tomai, Fabrizio; Pinto, Annamaria; Neri, Giandomenico; Procaccini, Enrica; Nudi, Alessandro; Frati, Giacomo; Biondi-Zoccai, Giuseppe

2017-10-15

The definition, presentation, and management of myocardial infarction (MI) have changed substantially in the last decade. Whether these changes have impacted on the presence, severity, and localization of necrosis at myocardial perfusion imaging (MPI) has not been appraised to date. Subjects undergoing MPI and reporting a history of clinical MI were shortlisted. We focused on the presence, severity, and localization of necrosis at MPI with a retrospective single-center analysis. A total of 10,476 patients were included, distinguishing 5 groups according to the period in which myocardial perfusion scintigraphy had been performed (2004 to 2005, 2006 to 2007, 2008 to 2009, 2010 to 2011, 2012 to 2013). Trend analysis showed over time a significant worsening in baseline features (e.g., age, diabetes mellitus, and Q waves at electrocardiogram), whereas medical therapy and revascularization were offered with increasing frequency. Over the years, there was also a lower prevalence of normal MPI (from 16.8% to 13.6%) and ischemic MPI (from 35.6% to 32.8%), and a higher prevalence of ischemic and necrotic MPI (from 12.0% to 12.7%) or solely necrotic MPI (from 35.7% to 40.9%, p <0.001). Yet the prevalence of severe ischemia decreased over time from 11.4% to 2.0%, with a similar trend for moderate ischemia (from 15.9% to 11.8%, p <0.001). Similarly sobering results were wound for the prevalence of severe necrosis (from 19.8% to 8.2%) and moderate necrosis (from 8.5% to 7.8%, p = 0.028). These trends were largely confirmed at regional level and after propensity score matching. In conclusion, the outlook of stable patients with previous MI has substantially improved in the last decade, with a decrease in the severity of residual myocardial ischemia and necrosis, despite an apparent worsening in baseline features. Copyright © 2017 Elsevier Inc. All rights reserved.

Value of the QRS complex in assessing left ventricular ejection fraction.

PubMed

Askenazi, J; Parisi, A F; Cohn, P F; Freedman, W B; Braunwald, E

1978-03-01

The relation between electrocardiographic findings and the angiographic left ventricular ejection fraction and the augmented ejection fraction after a premature ventricular contraction was investigated in 73 patients with documented chronic coronary artery disease. The patients were separated into four groups according to the presence or absence of abnormal Q waves. Twenty-four patients had diaphragmatic myocardial infarction, 21 had anterior myocardial infarction, 15 had both and 13 had no myocardial infarction. There was no statistically significant differences in cardiac index, left ventricular end-diastolic pressure or number of coronary vessels showing critical narrowing in the four groups. The sum of R waves (in mv) in leads aVL, aVF and V1 to V6 (sigmaR) was correlated with the ejection fraction (EF) and the augmented ejection fraction (EFa). EF in percent = 6.6 sigmaR mv + 9.4 (no. =73, r = 0.61); and EFa in percent = 8.6 sigmaR mv + 11.0 (no. = 73, r = 0.77). Among patients with sigmaR of less than 4.0 mv, augmented ejection fraction was less than 0.45 in 73 percent; among patients with sigmaR of 4.0 mv or more the augmented ejection fraction was greater than 0.45 in 93 percent (P less than 0.001). Thus, the sigmaR, calculated from six precordial and two augmented leads in patients with chronic coronary artery disease, correlated with both ejection fraction and augmented ejection fraction. The electrocardiogram in patients with coronary artery disease may prove useful as a simple, readily available and noninvasive guide in the assessment of left ventricular function in patients with coronary artery disease.

Aortic operation after previous coronary artery bypass grafting: management of patent grafts for myocardial protection.

PubMed

Nakajima, Masato; Tsuchiya, Koji; Fukuda, Shoji; Morimoto, Hironobu; Mitsumori, Yoshitaka; Kato, Kaori

2006-04-01

Aortic surgery for progressive aortic valve disease or aortic aneurysm after previous coronary artery bypass grafting (CABG) is a challenging procedure. We report the outcome of aortic reoperation after previous CABG and evaluate our management of patent grafts and our methods for obtaining myocardial protection. From February 2001 to July 2003, 6 patients with progressive aortic valve disease and aneurysm of the thoracic aorta were operated on. The group comprised 3 men and 3 women with a mean age of 67.6 years. There were 4 patients with an aneurysm of the aortic arch, 1 with chronic ascending aortic dissection, and 1 with progressive aortic valve stenosis. The interval between previous CABG and aortic surgery was 74.0 +/- 44.2 months. All reoperations were performed via median resternotomy. Myocardial protection was obtained by hypothermic perfusion of patent in-situ arterial grafts following cold-blood cardioplegia administration via the aortic root under aortic cross clamping. The operative procedure was aortic arch replacement in 4 patients, ascending aortic replacement with double CABG in 1, and aortic valve replacement in 1. All patients survived the reoperation. Postoperative maximum creatine kinase-MB was 49.2 +/- 29.8 and no new Q-waves occurred in the electrocardiogram nor were any new wall motion abnormalities recognized on echocardiography. There were no late deaths during a follow-up of 30.7 months. Reoperative aortic procedures after CABG can be performed safely with myocardial protection via hypothermic perfusion of a patent in-situ arterial graft.

Analysis of an Hp-Non-conforming Discontinuous Galerkin Spectral Element Method for Wave

DTIC Science & Technology

2011-04-01

Scientific Computing, 36 (2008), pp. 351–390. [25] Eleuterio F . Toro , Riemann Solvers and Numerical Methods for Fluid Dynamics, Springer, 1999. [26...denoted by ñ, and the contravariant flux [15] is defined as F̃i = Jeai · F , i = 1, 2, 3, with ai as the contravariant basis vectors. We now describe...wave propagation case by the following definitions, q = ( E v ) ∈ V, Q = ( I 0 0 ρI ) , g = ( 0 f ) ∈ V, with I denoting the fourth-order identity tensor

The clinical evaluation of the CADence device in the acoustic detection of coronary artery disease.

PubMed

Thomas, Joseph L; Ridner, Michael; Cole, Jason H; Chambers, Jeffrey W; Bokhari, Sabahat; Yannopoulos, Demetris; Kern, Morton; Wilson, Robert F; Budoff, Matthew J

2018-06-23

The noninvasive detection of turbulent coronary flow may enable diagnosis of significant coronary artery disease (CAD) using novel sensor and analytic technology. Eligible patients (n = 1013) with chest pain and CAD risk factors undergoing nuclear stress testing were studied using the CADence (AUM Cardiovascular Inc., Northfield MN) acoustic detection (AD) system. The trial was designed to demonstrate non-inferiority of AD for diagnostic accuracy in detecting significant CAD as compared to an objective performance criteria (sensitivity 83% and specificity 80%, with 15% non-inferiority margins) for nuclear stress testing. AD analysis was blinded to clinical, core lab-adjudicated angiographic, and nuclear data. The presence of significant CAD was determined by computed tomographic (CCTA) or invasive angiography. A total of 1013 subjects without prior coronary revascularization or Q-wave myocardial infarction were enrolled. Primary analysis was performed on subjects with complete angiographic and AD data (n = 763) including 111 subjects (15%) with severe CAD based on CCTA (n = 34) and invasive angiography (n = 77). The sensitivity and specificity of AD were 78% (p = 0.012 for non-inferiority) and 35% (p < 0.001 for failure to demonstrate non-inferiority), respectively. AD results had a high 91% negative predictive value for the presence of significant CAD. AD testing failed to demonstrate non-inferior diagnostic accuracy as compared to the historical performance of a nuclear stress OPC due to low specificity. AD sensitivity was non-inferior in detecting significant CAD with a high negative predictive value supporting a potential value in excluding CAD.

Idler-resonant intracavity KTA-based OPO pumped by a dual-loss modulated-Q-switched-laser with AOM and Cr4+:YAG

NASA Astrophysics Data System (ADS)

Qiao, Junpeng; Zhao, Shengzhi; Yang, Kejian; Zhao, Jia; Li, Guiqiu; Li, Dechun; Li, Tao; Qiao, Wenchao

2017-06-01

An idler-resonant KTiOAsO4 (KTA)-based intracavity optical parametric oscillator (IOPO) pumped by a dual-loss-modulated Q-switched laser with an acousto-optic modulator (AOM) and a Cr4+:YAG saturable absorber (Cr4+:YAG-SA) has been presented. By utilizing a type-II non-critically phase-matched KTA crystal, signal wave at 1535 nm and idler wave at 3467 nm have been generated. Under an incident pump power of 18.3 W, maximum output powers of 615 mW for signal wave and 228 mW for idler wave were obtained at an AOM modulation rate of 10 kHz, corresponding to a whole optical-to-optical conversion efficiency of 4.6%. The shortest pulse widths of signal and idler wave were measured to be 898 ps and 2.9 ns, corresponding to the highest peak powers of 68.4 and 7.9 kW, respectively. In comparison with IOPO pumped by a singly Q-switched laser with an AOM, the IOPO pumped by a doubly Q-switched laser (DIOPO) with an AOM and a Cr4+:YAG-SA can generate signal wave and idler wave with shorter pulse width and higher peak power. By considering the spatial Gaussian distribution of intracavity photon density, a set of coupled rate equations for the idler-resonant DIOPO were built for the first time to the best of our knowledge. The simulation results agreed well with the experimental results.

Characterization of myocardial lesions associated with cardiomyopathy syndrome in Atlantic salmon, Salmo salar L., using laser capture microdissection.

PubMed

Wiik-Nielsen, J; Løvoll, M; Fritsvold, C; Kristoffersen, A B; Haugland, Ø; Hordvik, I; Aamelfot, M; Jirillo, E; Koppang, E O; Grove, S

2012-12-01

Cardiomyopathy syndrome (CMS) in Atlantic salmon, Salmo salar L., is characterized by focal infiltration in the spongy myocardium and endocardium of the heart. The origin of the mononuclear infiltrate is unknown. Using experimentally infected fish, we investigated localization of the causative agent, piscine myocarditis virus (PMCV), within the heart and characterized the cell population associated with myocardial lesions. Cellular and transcriptional characteristics in the lesions were compared with adjacent non-infiltrated tissues using laser capture microdissection, RT-qPCR and immunohistochemistry. Our results reveal that PMCV is almost exclusively present in myocardial lesions. The inflammatory infiltrate comprises a variety of leucocyte populations, including T cells, B cells, MHC class II(+) and CD83(+) cells, most likely of the macrophage line. Correlation analyses demonstrated co-ordinated leucocyte activity at the site of the virus infection. Cellular proliferation and/or DNA repair was demonstrated within the myocardial lesions. Different cell populations, mainly myocytes, stained positive for proliferating cell nuclear antigen (PCNA). Densities of endothelial cells and fibroblasts were not significantly increased. The simultaneous presence of PMCV and various inflammatory cells in all myocardial lesions analysed may indicate that both viral lytic and immunopathological effects may contribute to the pathogenesis of CMS. © 2012 Blackwell Publishing Ltd.

An imprinted non-coding genomic cluster at 14q32 defines clinically relevant molecular subtypes in osteosarcoma across multiple independent datasets.

PubMed

Hill, Katherine E; Kelly, Andrew D; Kuijjer, Marieke L; Barry, William; Rattani, Ahmed; Garbutt, Cassandra C; Kissick, Haydn; Janeway, Katherine; Perez-Atayde, Antonio; Goldsmith, Jeffrey; Gebhardt, Mark C; Arredouani, Mohamed S; Cote, Greg; Hornicek, Francis; Choy, Edwin; Duan, Zhenfeng; Quackenbush, John; Haibe-Kains, Benjamin; Spentzos, Dimitrios

2017-05-15

A microRNA (miRNA) collection on the imprinted 14q32 MEG3 region has been associated with outcome in osteosarcoma. We assessed the clinical utility of this miRNA set and their association with methylation status. We integrated coding and non-coding RNA data from three independent annotated clinical osteosarcoma cohorts (n = 65, n = 27, and n = 25) and miRNA and methylation data from one in vitro (19 cell lines) and one clinical (NCI Therapeutically Applicable Research to Generate Effective Treatments (TARGET) osteosarcoma dataset, n = 80) dataset. We used time-dependent receiver operating characteristic (tdROC) analysis to evaluate the clinical value of candidate miRNA profiles and machine learning approaches to compare the coding and non-coding transcriptional programs of high- and low-risk osteosarcoma tumors and high- versus low-aggressiveness cell lines. In the cell line and TARGET datasets, we also studied the methylation patterns of the MEG3 imprinting control region on 14q32 and their association with miRNA expression and tumor aggressiveness. In the tdROC analysis, miRNA sets on 14q32 showed strong discriminatory power for recurrence and survival in the three clinical datasets. High- or low-risk tumor classification was robust to using different microRNA sets or classification methods. Machine learning approaches showed that genome-wide miRNA profiles and miRNA regulatory networks were quite different between the two outcome groups and mRNA profiles categorized the samples in a manner concordant with the miRNAs, suggesting potential molecular subtypes. Further, miRNA expression patterns were reproducible in comparing high-aggressiveness versus low-aggressiveness cell lines. Methylation patterns in the MEG3 differentially methylated region (DMR) also distinguished high-aggressiveness from low-aggressiveness cell lines and were associated with expression of several 14q32 miRNAs in both the cell lines and the large TARGET clinical dataset. Within the limits of available CpG array coverage, we observed a potential methylation-sensitive regulation of the non-coding RNA cluster by CTCF, a known enhancer-blocking factor. Loss of imprinting/methylation changes in the 14q32 non-coding region defines reproducible previously unrecognized osteosarcoma subtypes with distinct transcriptional programs and biologic and clinical behavior. Future studies will define the precise relationship between 14q32 imprinting, non-coding RNA expression, genomic enhancer binding, and tumor aggressiveness, with possible therapeutic implications for both early- and advanced-stage patients.

Coulomb wave functions in momentum space

DOE PAGES

Eremenko, V.; Upadhyay, N. J.; Thompson, I. J.; ...

2015-10-15

We present an algorithm to calculate non-relativistic partial-wave Coulomb functions in momentum space. The arguments are the Sommerfeld parameter η, the angular momentum l, the asymptotic momentum q and the 'running' momentum p, where both momenta are real. Since the partial-wave Coulomb functions exhibit singular behavior when p → q, different representations of the Legendre functions of the 2nd kind need to be implemented in computing the functions for the values of p close to the singularity and far away from it. The code for the momentum-space Coulomb wave functions is applicable for values of vertical bar eta vertical barmore » in the range of 10 -1 to 10, and thus is particularly suited for momentum space calculations of nuclear reactions.« less

Preoperative and intraoperative predictors of cardiac adverse events after general, vascular, and urological surgery.

PubMed

Kheterpal, Sachin; O'Reilly, Michael; Englesbe, Michael J; Rosenberg, Andrew L; Shanks, Amy M; Zhang, Lingling; Rothman, Edward D; Campbell, Darrell A; Tremper, Kevin K

2009-01-01

The authors sought to determine the incidence and risk factors for perioperative cardiac adverse events (CAEs) after noncardiac surgery using detailed preoperative and intraoperative hemodynamic data. The authors conducted a prospective observational study at a single university hospital from 2002 to 2006. All American College of Surgeons-National Surgical Quality Improvement Program patients undergoing general, vascular, and urological surgery were included. The CAE outcome definition included cardiac arrest, non-ST elevation myocardial infarction, Q-wave myocardial infarction, and new clinically significant cardiac dysrhythmia within the first 30 postoperative days. Four years of data demonstrated that of 7,740 noncardiac operations, 83 patients (1.1%) experienced a CAE within 30 days. Nine independent predictors were identified (P < or = 0.05): age > or = 68, body mass index > or = 30, emergent surgery, previous coronary intervention or cardiac surgery, active congestive heart failure, cerebrovascular disease, hypertension, operative duration > or = 3.8 h, and the administration of 1 or more units of packed red blood cells intraoperatively. The c-statistic of this model was 0.81 +/- 0.02. Univariate analysis demonstrated that high-risk patients experiencing a CAE were more likely to experience an episode of mean arterial pressure < 50 mmHg (6% vs. 24%, P = 0.02), experience an episode of 40% decrease in mean arterial pressure (26% vs. 53%, P = 0.01), and an episode of heart rate > 100 (22% vs. 34%, P = 0.05). In comparison with current risk stratification indices, the inclusion of intraoperative elements improves the ability to predict a perioperative CAE after noncardiac surgery.

The Kalman-Tran-D'Souza model and the semileptonic decay rates of heavy baryons

NASA Astrophysics Data System (ADS)

D'Souza, I.; Kalman, C. S.; Kulikov, P. Yu.; Narodetskii, I. M.

2001-03-01

We present an investigation of the inclusive semileptonic decay widths of the heavy baryons Λ Q, Σ Q and Ξ Q, ( q = b, c) performed within a relativistic constituent quark model, formulated on the light-front. In a way conceptually similar to the deep-inelastic scattering case, the H Q-baryon inclusive width is expressed as the integral of the free Q-quark partial width multiplied by a bound-state factor related to the Q-quark distribution function in the H Q. The non-perturbative meson structure is described through the quark-model wave functions, constructed via the Hamiltonian light-front formalism using as input the Kalman-Tran-D'Souza equal time wave functions. A link between spectroscopic quark models and the H Q decay physics is obtained in this way. It is shown that the bound-state effects and the Fermi motion of the b-quark remarkably reduce the decay rate with respect to the free-quark result. Our predictions for the BR(Λ c → X sl ν e) and BR(Λ b → X cl ν e) decays are in good agreement with existing data.

Automatic learning of rules. A practical example of using artificial intelligence to improve computer-based detection of myocardial infarction and left ventricular hypertrophy in the 12-lead ECG.

PubMed

Kaiser, W; Faber, T S; Findeis, M

1996-01-01

The authors developed a computer program that detects myocardial infarction (MI) and left ventricular hypertrophy (LVH) in two steps: (1) by extracting parameter values from a 10-second, 12-lead electrocardiogram, and (2) by classifying the extracted parameter values with rule sets. Every disease has its dedicated set of rules. Hence, there are separate rule sets for anterior MI, inferior MI, and LVH. If at least one rule is satisfied, the disease is said to be detected. The computer program automatically develops these rule sets. A database (learning set) of healthy subjects and patients with MI, LVH, and mixed MI+LVH was used. After defining the rule type, initial limits, and expected quality of the rules (positive predictive value, minimum number of patients), the program creates a set of rules by varying the limits. The general rule type is defined as: disease = lim1l < p1 < or = lim1u and lim2l < p2 < or = lim2u and ... limnl < pn < or = limnu. When defining the rule types, only the parameters (p1 ... pn) that are known as clinical electrocardiographic criteria (amplitudes [mV] of Q, R, and T waves and ST-segment; duration [ms] of Q wave; frontal angle [degrees]) were used. This allowed for submitting the learned rule sets to an independent investigator for medical verification. It also allowed the creation of explanatory texts with the rules. These advantages are not offered by the neurons of a neural network. The learned rules were checked against a test set and the following results were obtained: MI: sensitivity 76.2%, positive predictive value 98.6%; LVH: sensitivity 72.3%, positive predictive value 90.9%. The specificity ratings for MI are better than 98%; for LVH, better than 90%.

Taurine Supplementation Improves Functional Capacity, Myocardial Oxygen Consumption, and Electrical Activity in Heart Failure.

PubMed

Ahmadian, Mehdi; Dabidi Roshan, Valiollah; Ashourpore, Eadeh

2017-07-04

Taurine is an amino acid found abundantly in the heart in very high concentrations. It is assumed that taurine contributes to several physiological functions of mammalian cells, such as osmoregulation, anti-inflammation, membrane stabilization, ion transport modulation, and regulation of oxidative stress and mitochondrial protein synthesis. The objective of the current study was to evaluate the effectiveness of taurine supplementation on functional capacity, myocardial oxygen consumption, and electrical activity in patients with heart failure. In a double-blind and randomly designed study, 16 patients with heart failure were assigned to two groups: taurine (TG, n = 8) and placebo (PG, n = 8). TG received 500-mg taurine supplementation three times per day for two weeks. Significant decrease in the values of Q-T segments (p < 0.01) and significant increase in the values of P-R segments (p < 0.01) were detected following exercise post-supplementation in TG rather than in PG. Significantly higher values of taurine concentration, T wave, Q-T segment, physical capacities, and lower values of cardiovascular capacities were detected post-supplementation in TG as compared with PG (all p values <0.01). Taurine significantly enhanced the physical function and significantly reduced the cardiovascular function parameters following exercise. Our results also suggest that the short-term taurine supplementation is an effective strategy for improving some selected hemodynamic parameters in heart failure patients. Together, these findings support the view that taurine improves cardiac function and functional capacity in patients with heart failure. This idea warrants further study.

Myocardial effects of local shock wave therapy in a Langendorff model.

PubMed

Becker, M; Goetzenich, A; Roehl, A B; Huebel, C; de la Fuente, M; Dietz-Laursonn, K; Radermacher, K; Rossaint, R; Hein, M

2014-01-01

Applying shock waves to the heart has been reported to stimulate the heart and alter cardiac function. We hypothesized that shock waves could be used to diagnose regional viability. We used a Langendorff model to investigate the acute effects of shock waves at different energy levels and times related to systole, cycle duration and myocardial function. We found only a small time window to use shock waves. Myocardial fibrillation or extrasystolic beats will occur if the shock wave is placed more than 15 ms before or 30 ms after the onset of systole. Increased contractility and augmented relaxation were observed after the second beat, and these effects decreased after prolonging the shock wave delay from 15 ms before to 30 ms after the onset of systole. An energy dependency could be found only after short delays (-15 ms). The involved processes might include post-extrasystolic potentiation and simultaneous pacing. In summary, we found that low-energy shock waves can be a useful tool to stimulate the myocardium at a distance and influence function. Copyright © 2013 Elsevier B.V. All rights reserved.

On the role of flood wave celerity-discharge relationship and its applications on hydrological studies

NASA Astrophysics Data System (ADS)

Fleischmann, Ayan; Collischonn, Walter; Jardim, Pedro; Meyer, Aline; Paiva, Rodrigo

2017-04-01

The non-linear relationship between flood wave celerity (C) and discharge (Q) plays an important role on defining how flood waves are routed through the river network. The behavior of this curve is driven by cross section geometry, which leads to increasing celerity with discharge in rivers without floodplains. In reaches with floodplain storage, C may decrease after bankfull Q. Thus, in a set of studies we investigate the effects of C x Q relationships on the basin hydrological response. (i) We studied these curves for several Brazilian river reaches, and analyzed to which extent they are related to river channel geometry and other characteristics (e.g., slope, width, drainage area and sinuosity). (ii) It is shown through empirical, analytical and numerical experiments how C x Q relation affects hydrograph skewness, and how the decreasing relationship existent in rivers with important floodplain storage leads to negatively skewed hydrographs, such as in the Amazon and Pantanal regions, which could be used to infer important floodplain processes (e.g., presence of overbank flow wetlands, which feature negatively skewed hydrographs or interfluvial wetlands not directly connected to rivers). (iii) Finally, we found that it is possible to use these concepts to calibrate the effective bathymetry of a hydrodynamic model by fitting the C x Q relationship using SCE-UA optimization method. Our results show how important it is to investigate the non-linear hydraulic processes occurring throughout river basins to understand the overall hydrological response, and propose new frameworks to assist such studies, including the evaluation of hydrograph skewness and estimation of hydraulic geometry.

Electrocardiologic and related methods of non-invasive detection and risk stratification in myocardial ischemia: state of the art and perspectives

PubMed Central

Huebner, Thomas; Goernig, Matthias; Schuepbach, Michael; Sanz, Ernst; Pilgram, Roland; Seeck, Andrea; Voss, Andreas

2010-01-01

Background: Electrocardiographic methods still provide the bulk of cardiovascular diagnostics. Cardiac ischemia is associated with typical alterations in cardiac biosignals that have to be measured, analyzed by mathematical algorithms and allegorized for further clinical diagnostics. The fast growing fields of biomedical engineering and applied sciences are intensely focused on generating new approaches to cardiac biosignal analysis for diagnosis and risk stratification in myocardial ischemia. Objectives: To present and review the state of the art in and new approaches to electrocardiologic methods for non-invasive detection and risk stratification in coronary artery disease (CAD) and myocardial ischemia; secondarily, to explore the future perspectives of these methods. Methods: In follow-up to the Expert Discussion at the 2008 Workshop on "Biosignal Analysis" of the German Society of Biomedical Engineering in Potsdam, Germany, we comprehensively searched the pertinent literature and databases and compiled the results into this review. Then, we categorized the state-of-the-art methods and selected new approaches based on their applications in detection and risk stratification of myocardial ischemia. Finally, we compared the pros and cons of the methods and explored their future potentials for cardiology. Results: Resting ECG, particularly suited for detecting ST-elevation myocardial infarctions, and exercise ECG, for the diagnosis of stable CAD, are state-of-the-art methods. New exercise-free methods for detecting stable CAD include cardiogoniometry (CGM); methods for detecting acute coronary syndrome without ST elevation are Body Surface Potential Mapping, functional imaging and CGM. Heart rate variability and blood pressure variability analyses, microvolt T-wave alternans and signal-averaged ECG mainly serve in detecting and stratifying the risk for lethal arrythmias in patients with myocardial ischemia or previous myocardial infarctions. Telemedicine and ambient-assisted living support the electrocardiological monitoring of at-risk patients. Conclusions: There are many promising methods for the exercise-free, non-invasive detection of CAD and myocardial ischemia in the stable and acute phases. In the coming years, these new methods will help enhance state-of-the-art procedures in routine diagnostics. The future can expect that equally novel methods for risk stratification and telemedicine will transition into clinical routine. PMID:21063467

Effects of the non-extensive parameter on the propagation of ion acoustic waves in five-component cometary plasma system

NASA Astrophysics Data System (ADS)

Mahmoud, Abeer A.

2018-01-01

Some important evolution nonlinear partial differential equations are derived using the reductive perturbation method for unmagnetized collisionless system of five component plasma. This plasma system is a multi-ion contains negatively and positively charged Oxygen ions (heavy ions), positive Hydrogen ions (lighter ions), hot electrons from solar origin and colder electrons from cometary origin. The positive Hydrogen ion and the two types of electrons obey q-non-extensive distributions. The derived equations have three types of ion acoustic waves, which are soliton waves, shock waves and kink waves. The effects of the non-extensive parameters for the hot electrons, the colder electrons and the Hydrogen ions on the propagation of the envelope waves are studied. The compressive and rarefactive shapes of the three envelope waves appear in this system for the first order of the power of the nonlinearity strength with different values of non-extensive parameters. For the second order, the strength of nonlinearity will increase and the compressive type of the envelope wave only appears.

Electromechanical wave imaging and electromechanical wave velocity estimation in a large animal model of myocardial infarction.

PubMed

Costet, Alexandre; Melki, Lea; Sayseng, Vincent; Hamid, Nadira; Nakanishi, Koki; Wan, Elaine; Hahn, Rebecca; Homma, Shunichi; Konofagou, Elisa

2017-11-29

Echocardiography is often used in the clinic for detection and characterization of myocardial infarction. Electromechanical wave imaging (EWI) is a non-invasive ultrasound-based imaging technique based on time-domain incremental motion and strain estimation that can evaluate changes in contractility in the heart. In this study, electromechanical activation is assessed in infarcted heart to determine whether EWI is capable of detecting and monitoring infarct formation. Additionally, methods for estimating electromechanical wave (EW) velocity are presented, and changes in the EW propagation velocity after infarct formation are studied. Five (n  =  5) adult mongrels were used in this study. Successful infarct formation was achieved in three animals by ligation of the left anterior descending (LAD) coronary artery. Dogs were survived for a few days after LAD ligation and monitored daily with EWI. At the end of the survival period, dogs were sacrificed and TTC (tetrazolium chloride) staining confirmed the formation and location of the infarct. In all three dogs, as soon as day 1 EWI was capable of detecting late-activated and non-activated regions, which grew over the next few days. On final day images, the extent of these regions corresponded to the location of infarct as confirmed by staining. EW velocities in border zones of infarct were significantly lower post-infarct formation when compared to baseline, whereas velocities in healthy tissues were not. These results indicate that EWI and EW velocity might help with the detection of infarcts and their border zones, which may be useful for characterizing arrhythmogenic substrate.

Electromechanical wave imaging and electromechanical wave velocity estimation in a large animal model of myocardial infarction

NASA Astrophysics Data System (ADS)

Costet, Alexandre; Melki, Lea; Sayseng, Vincent; Hamid, Nadira; Nakanishi, Koki; Wan, Elaine; Hahn, Rebecca; Homma, Shunichi; Konofagou, Elisa

2017-12-01

Echocardiography is often used in the clinic for detection and characterization of myocardial infarction. Electromechanical wave imaging (EWI) is a non-invasive ultrasound-based imaging technique based on time-domain incremental motion and strain estimation that can evaluate changes in contractility in the heart. In this study, electromechanical activation is assessed in infarcted heart to determine whether EWI is capable of detecting and monitoring infarct formation. Additionally, methods for estimating electromechanical wave (EW) velocity are presented, and changes in the EW propagation velocity after infarct formation are studied. Five (n  =  5) adult mongrels were used in this study. Successful infarct formation was achieved in three animals by ligation of the left anterior descending (LAD) coronary artery. Dogs were survived for a few days after LAD ligation and monitored daily with EWI. At the end of the survival period, dogs were sacrificed and TTC (tetrazolium chloride) staining confirmed the formation and location of the infarct. In all three dogs, as soon as day 1 EWI was capable of detecting late-activated and non-activated regions, which grew over the next few days. On final day images, the extent of these regions corresponded to the location of infarct as confirmed by staining. EW velocities in border zones of infarct were significantly lower post-infarct formation when compared to baseline, whereas velocities in healthy tissues were not. These results indicate that EWI and EW velocity might help with the detection of infarcts and their border zones, which may be useful for characterizing arrhythmogenic substrate.

Multi-operational tuneable Q-switched mode-locking Er fibre laser

NASA Astrophysics Data System (ADS)

Qamar, F. Z.

2018-01-01

A wavelength-spacing tuneable, Q-switched mode-locking (QML) erbium-doped fibre laser based on non-linear polarization rotation controlled by four waveplates and a cube polarizer is proposed. A mode-locked pulse train using two quarter-wave plates and a half-wave plate (HWP) is obtained first, and then an extra HWP is inserted into the cavity to produce different operation regimes. The evolutions of temporal and spectral dynamics with different orientation angles of the extra HWP are investigated. A fully modulated stable QML pulse train is observed experimentally. This is, to the author’s best knowledge, the first experimental work reporting QML operation without adding an extra saturable absorber inside the laser cavity. Multi-wavelength pulse laser operation, multi-pulse train continuous-wave mode-locking operation and pulse-splitting operations are also reported at certain HWP angles. The observed operational dynamics are interpreted as a mutual interaction of dispersion, non-linear effect and insertion loss. This work provides a new mechanism for fabricating cheap tuneable multi-wavelength lasers with QML pulses.

3D Myocardial Elastography In Vivo.

PubMed

Papadacci, Clement; Bunting, Ethan A; Wan, Elaine Y; Nauleau, Pierre; Konofagou, Elisa E

2017-02-01

Strain evaluation is of major interest in clinical cardiology as it can quantify the cardiac function. Myocardial elastography, a radio-frequency (RF)-based cross-correlation method, has been developed to evaluate the local strain distribution in the heart in vivo. However, inhomogeneities such as RF ablation lesions or infarction require a three-dimensional approach to be measured accurately. In addition, acquisitions at high volume rate are essential to evaluate the cardiac strain in three dimensions. Conventional focused transmit schemes using 2D matrix arrays, trade off sufficient volume rate for beam density or sector size to image rapid moving structure such as the heart, which lowers accuracy and precision in the strain estimation. In this study, we developed 3D myocardial elastography at high volume rates using diverging wave transmits to evaluate the local axial strain distribution in three dimensions in three open-chest canines before and after radio-frequency ablation. Acquisitions were performed with a 2.5 MHz 2D matrix array fully programmable used to emit 2000 diverging waves at 2000 volumes/s. Incremental displacements and strains enabled the visualization of rapid events during the QRS complex along with the different phases of the cardiac cycle in entire volumes. Cumulative displacement and strain volumes depict high contrast between non-ablated and ablated myocardium at the lesion location, mapping the tissue coagulation. 3D myocardial strain elastography could thus become an important technique to measure the regional strain distribution in three dimensions in humans.

Ultrasound Backscatter Tensor Imaging (BTI): Analysis of the spatial coherence of ultrasonic speckle in anisotropic soft tissues

PubMed Central

Papadacci, Clement; Tanter, Mickael; Pernot, Mathieu; Fink, Mathias

2014-01-01

The assessment of fiber architecture is of major interest in the progression of myocardial disease. Recent techniques such as Magnetic Resonance (MR) Diffusion Tensor Imaging or Ultrasound Elastic Tensor Imaging (ETI) can derive the fiber directions by measuring the anisotropy of water diffusion or tissue elasticity, but these techniques present severe limitations in clinical setting. In this study, we propose a new technique, the Backscatter Tensor Imaging (BTI) which enables determining the fibers directions in skeletal muscles and myocardial tissues, by measuring the spatial coherence of ultrasonic speckle. We compare the results to ultrasound ETI. Acquisitions were performed using a linear transducer array connected to an ultrasonic scanner mounted on a motorized rotation device with angles from 0° to 355° by 5° increments to image ex vivo bovine skeletal muscle and porcine left ventricular myocardial samples. At each angle, multiple plane waves were transmitted and the backscattered echoes recorded. The coherence factor was measured as the ratio of coherent intensity over incoherent intensity of backscattered echoes. In skeletal muscle, maximal/minimal coherence factor was found for the probe parallel/perpendicular to the fibers. In myocardium, the coherence was assessed across the entire myocardial thickness, and the position of maxima and minima varied transmurally due to the complex fibers distribution. In ETI, the shear wave speed variation with the probe angle was found to follow the coherence variation. Spatial coherence can thus reveal the anisotropy of the ultrasonic speckle in skeletal muscle and myocardium. BTI could be used on any type of ultrasonic scanner with rotative phased-array probes or 2-D matrix probes for non-invasive evaluation of myocardial fibers. PMID:24859662

Mechanisms of myocardial capture and temporal excitable gap during spiral wave reentry in a bidomain model.

PubMed

Ashihara, Takashi; Namba, Tsunetoyo; Ikeda, Takanori; Ito, Makoto; Nakazawa, Kazuo; Trayanova, Natalia

2004-02-24

Recent studies have demonstrated that regional capture during cardiac fibrillation is associated with an elevated capture threshold. It is typically assumed that the temporal excitable gap (capture window) during fibrillation reflects the size of the spatial excitable gap (excitable tissue between fibrillation waves). Because capture threshold is high, virtual electrode polarization is expected to be involved in the process. However, little is known about the underlying mechanisms of myocardial capture during fibrillation. To clarify these issues, we conducted altogether 3168 simulations of single spiral wave capture in a bidomain sheet. Unipolar stimuli of strengths 4, 8, 16, and 24 mA and 2-ms duration were delivered at 99 locations in the sheet. We found that cathode-break rather than cathode-make excitation was the dominant mechanism of myocardial capture. When the stimulation site was located diagonally with respect to the core (upper left or lower right if the spiral wave rotates counterclockwise), the cathode-break excitation easily invaded the spatial excitable gap and resulted in a successful capture as a result of the formation of virtual anodes in the direction of the myocardial fibers. Thus, the spatial distribution of the temporal excitable gap did not reflect the spatial excitable gap. The areas exhibiting wide temporal excitable gaps were areas in which the cathode-break excitation wave fronts easily invaded the spatial excitable gap via the virtual anodes. This study provides mechanistic insight into myocardial capture.

Reduction of coenzyme q10 content: a possible effect of isoproterenol on heart failure and myocardial infarction in rat.

PubMed

Khorrami, A; Garjani, A; Ghanbarzadeh, S; Andalib, S

2014-04-01

Myocardial infarction (MI) was induced by subcutaneous injection of isoproterenol (ISO) to investigate the effect of ISO on Coenzyme Q10 (CoQ10) content of myocardium and subsequent effects on lipid peroxidation, electrocardiogram pattern and hemodynamic parameters of the rat's heart.36 male Wistar rats were divided randomly into 6 groups. To induce heart failure (HF) and MI, 10 and 100 mg/kg of ISO was administered subcutaneously for 10 and 2 consecutive days, respectively. The effects of ISO on myocardium CoQ10 content, concentration of malondialdehyde, ECG pattern and hemodynamic parameters of heart were analyzed.ISO-treated rats showed significant alteration in heart hemodynamic parameters such as reduction of left-ventricular systolic pressure, maximum and minimum rate of developed left ventricular pressure, besides increase of left ventricular end-diastolic pressure. Significant depletion of heart CoQ10 content (from 4.57 and 4.55 µg/100 mg tissue in control groups to 2.85 and 2.89 µg/100 mg tissue in ISO-induced HF and MI groups respectively) and increase in tissue levels of malondialdehyde (47.1 and 53.8 nmol/100 mg tissue in ISO-induced HF and MI groups, respectively) were also observed in ISO-treated animals compared with the normal animals (17.4 and 18.8 nmol/100 mg tissue in control groups, respectively). Additionally CoQ10 improved ISO effects on hemodynamic parameters and ECG pattern in ISO-induced HF and myocardial injury.The present findings have demonstrated that the cardiotoxic effects of ISO such as oxidative damage and hemodynamic declination might be related to depletion of CoQ10 concentration. © Georg Thieme Verlag KG Stuttgart · New York.

Schizophrenia and chromosomal deletions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindsay, E.A.; Baldini, A.; Morris, M. A.

Recent genetic linkage analysis studies have suggested the presence of a schizophrenia locus on the chromosomal region 22q11-q13. Schizophrenia has also been frequently observed in patients affected with velo-cardio-facial syndrome (VCFS), a disorder frequently associated with deletions within 22q11.1. It has been hypothesized that psychosis in VCFS may be due to deletion of the catechol-o-methyl transferase gene. Prompted by these observations, we screened for 22q11 deletions in a population of 100 schizophrenics selected from the Maryland Epidemiological Sample. Our results show that there are schizophrenic patients carrying a deletion of 22q11.1 and a mild VCFS phenotype that might remain unrecognized.more » These findings should encourage a search for a schizophrenia-susceptibility gene within the deleted region and alert those in clinical practice to the possible presence of a mild VCFS phenotype associated with schizophrenia. 9 refs.« less

Persistently high prevalence and unrecognized HIV infection among men who have sex with men in Baltimore: the BESURE Study

PubMed Central

German, Danielle; Sifakis, Frangiscos; Maulsby, Cathy; Towe, Vivian L.; Flynn, Colin P.; Latkin, Carl A.; Celentano, David D.; Hauck, Heather; Holtgrave, David R.

2017-01-01

Background Given high rates of HIV among Baltimore MSM, we examined characteristics associated with HIV prevalence and unrecognized HIV infection among Baltimore MSM at two time points. Methods Cross-sectional behavioral surveys and HIV testing in 2004–2005 and 2008 using venue-based sampling among adult Baltimore men at MSM-identified locations. MSM was defined as sex with a male partner in the past year. Bivariate and backwards stepwise regression identified characteristics associated with HIV and unrecognized infection. Findings HIV prevalence was 37.7% overall in 2004–2005 (n=645) and 37.5% in 2008 (n=448), 51.4% and 44.7% among Black MSM, and 12.9% and 18.3% among non-Hispanic White MSM. Compared to non-Hispanic White MSM, Black MSM were 4.0 times (95% C.I.: 2.3, 7.0) more likely to be HIV-positive in 2004–2005 and 2.5 times (95% C.I.: 1.5, 4.0) more likely in 2008. Prevalence of unrecognized HIV infection was 58.4% overall in 2004–2005 and 74.4% in 2008, 63.8% and 76.9% among Black MSM, and 15.4% and 47.4% among non-Hispanic White MSM. In adjusted models, unrecognized infection was significantly associated with minority race/ethnicity, younger age, and no prior year doctor visits in 2004–5 and with younger age and no prior year doctor visits in 2008. Conclusion High rates of HIV infection and substantial rates of unrecognized HIV infection among Baltimore MSM, particularly men of color and young men, require urgent public and private sector attention and increased prevention response. PMID:21297479

Prognostic significance of electrocardiographic Q-waves in a low-risk population.

PubMed

Godsk, Peter; Jensen, Jan Skov; Abildstrøm, Steen Z; Appleyard, Merete; Pedersen, Sune; Mogelvang, Rasmus

2012-07-01

In individuals without known heart disease, electrocardiographic Q-waves predict a poor prognosis. We aimed to examine whether prognostic information can be derived from the size and location of Q-waves in persons from the general population without known ischaemic heart disease (IHD) or heart failure (HF). Electrocardiograms (ECGs) of 5381 persons without known IHD or HF from the 4th Copenhagen City Heart Study were reviewed and Q-waves were classified according to their size and location. Multivariate Cox proportional hazards regression models were used to examine the associations of Q-waves adjusted for age, hypertension, diabetes, and estimated glomerular filtration rate with the risk of the combined endpoint of death and hospitalization for IHD. During a median of 7.8 years of follow-up, 1003 persons reached the combined endpoint. One hundred and fourteen (2.1%) had pathological Q-waves, of whom 44% suffered from an event compared with 18% from the control group, P< 0.001. Persons with hypertension, diabetes, and impaired renal function were more likely to have Q-waves. Even small Q-waves (i.e. Minnesota code 1.2.x-1.3.x) were associated with a poor prognosis, hazard ratio (HR) 1.4 [95% confidence interval (CI): 1.0-2.0; P< 0.05], though not as grave as large Q-waves (i.e. Minnesota code 1.1.x) HR 2.8 (95%CI: 1.6-5.0; P< 0.001). Conversely, there was no difference in the outcome of patients with anteriorly HR 1.6 (95%CI: 1.1-2.4) vs. posteriorly HR 1.5 (95%CI: 0.9-2.4) located Q-waves (P= 0.85). In the general population without known IHD or HF, even small Q-waves in the ECG are associated with a poor prognosis.

An ischemia-guided approach for risk stratification in patients with acute coronary syndromes.

PubMed

Pepine, C J

2000-12-28

The optimal management approach for patients with non-ST-segment elevation acute coronary syndromes continues to be an issue of debate. An ischemia-guided strategy appears to be effective as an alternative to either a very conservative "wait-and-see" approach or a very aggressive routine revascularization approach. The need for another approach is supported by the lack of conclusive evidence-based results favoring an early routine invasive treatment strategy. In the Thrombolysis in Myocardial Infarction (TIMI) IIIB trial, there were no differences in the incidence of death or myocardial infarction (MI) between patients treated with an early invasive approach and those treated with a conservative approach to treatment. Significantly worse outcomes were shown in patients assigned to an early invasive strategy in the Veterans Affairs Non-Q-Wave Infarction Strategies in Hospital (VANQWISH) trial at 1-year follow-up (111 clinical events in the invasive group vs 85 in the conservative group; p = 0.05). Registry information, including that from the Organization to Assess Strategies for Ischemic Syndromes (OASIS), which included approximately 8,000 patients with unstable angina or suspected MI, has even suggested an excess hazard with a routine invasive approach. Patients with non-ST-segment elevation MI observed in the Global Use of Strategies to Open Occluded Coronary Arteries in Acute Coronary Syndromes (GUSTO)-IIB and Platelet IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trials also fared better with an ischemia-guided strategy. Even the recent FRagmin and Fast Revascularization during InStability in Coronary artery disease (FRISC II) trial investigators had to be very selective relative to eliminating high-risk patients in the first week and treating with intense anti-ischemic therapy and 5-7 days of low-molecular-weight heparin therapy to show an advantage for assigned revascularization. A careful clinical evaluation with attention to early risk stratification is essential in the ischemia-guided approach. The Braunwald classification for unstable angina helps identify independent clinical predictors of a poor outcome; high risk is clearly associated with Braunwald class III and type C. Electrocardiographic and biochemical markers for myocardial necrosis (cardiac troponin T or I) are important tools for assessing the presence and degree of ischemia and associated risk for adverse outcome. Noninvasive evaluation of left ventricular ejection fraction is essential for identifying those at high risk due to impaired contractile function. When these conventional markers do not provide conclusive information, noninvasive stress testing is most helpful to further identify those at highest risk for revascularization.

Emotions delay care-seeking in patients with an acute myocardial infarction.

PubMed

Nymark, Carolin; Mattiasson, Anne-Cathrine; Henriksson, Peter; Kiessling, Anna

2014-02-01

In acute myocardial infarction the risk of death and loss of myocardial tissue is at its highest during the first few hours. However, the process from symptom onset to the decision to seek medical care can take time. To comprehend patients' pre-hospital delay, attention must be focused on the circumstances preceding the decision to seek medical care. To add a deeper understanding of patients' thoughts, feelings and actions that preceded the decision to seek medical care when afflicted by an acute myocardial infarction. Fourteen men and women with a first or second acute myocardial infarction were interviewed individually in semi-structured interviews. Data were analysed by qualitative content analysis. Four themes were conceptualized: 'being incapacitated by fear, anguish and powerlessness', 'being ashamed of oneself', 'fear of losing a healthy identity' and 'striving to avoid fear by not interacting with others'. Patients were torn between feelings such as anguish, fear, shame and powerlessness. They made an effort to uphold their self-image as being a healthy person thus affected by an unrecognized discomfort. This combined with a struggle to protect others from involvement, strengthened the barriers to seeking care. The present study indicates that emotional reactions are important and influence patients' pre-hospital behaviour. Being ashamed of oneself stood out as a novel finding. Emotions might be an important explanation of undesired and persisting patient delays. However, our findings have to and should be evaluated quantitatively. Such a study is in progress.

Outcomes After Orbital Atherectomy of Severely Calcified Left Main Lesions: Analysis of the ORBIT II Study.

PubMed

Lee, Michael S; Shlofmitz, Evan; Shlofmitz, Richard; Sahni, Sheila; Martinsen, Brad; Chambers, Jeffrey

2016-09-01

The ORBIT II trial reported excellent outcomes in patients with severely calcified coronary lesions treated with orbital atherectomy. Severe calcification of the left main (LM) artery represents a complex coronary lesion subset. This study evaluated the safety and efficacy of coronary orbital atherectomy to prepare severely calcified protected LM artery lesions for stent placement. The ORBIT II trial was a prospective, multicenter clinical trial that enrolled 443 patients with severely calcified coronary lesions in the United States. The major adverse cardiac event (MACE) rate through 2 years post procedure, defined by cardiac death, myocardial infarction (CK-MB >3x upper limit of normal with or without a new pathologic Q-wave) and target-vessel revascularization, was compared in the LM and non-left main (NLM) groups. Among the 443 patients, a total of 10 underwent orbital atherectomy of protected LM artery lesions. At 2 years, there was no significant difference in the 2-year MACE rate in the LM and NLM groups (30.0% vs 19.1%, respectively; P=.36). Cardiac death was low in both groups (0% vs 4.4%, respectively; P=.99). Myocardial infarction occurred within 30 days in both groups (10.0% vs 9.7%, respectively; P=.99). Severe dissection, perforation, persistent slow flow, and persistent no reflow did not occur in the LM group. Abrupt closure occurred in 1 patient in the LM group. Orbital atherectomy for patients with heavily calcified LM coronary artery lesions is safe and feasible. Further studies are needed to assess the safety and efficacy of orbital atherectomy in patients with severely calcified LM artery lesions.

Stenting of long coronary artery lesions: initial angiographic results and 6-month clinical outcome of the micro stent II-XL.

PubMed

Schalij, M J; Udayachalerm, W; Oemrawsingh, P; Jukema, J W; Reiber, J H; Bruschke, A V

1999-09-01

To evaluate the results of long Micro Stent II (MS-XL) implantations, 119 MS-XLs were implanted in 102 patients (age, 62.83 years). Nineteen stents (16%) were implanted in saphenous vein grafts; 100 stents (84%) were implanted in native coronary arteries. Twenty-five patients (25%) were treated because of acute myocardial infarction (AMI); 30 patients (29%) because of unstable angina or angina class IV, and 47 patients (46%) because of stable angina. Eighty-six de novo lesions (84%) and 16 restenotic lesions (16%) were treated. Indications for stent implantation include elective, 61 patients (60%); suboptimal balloon angioplasty result, 22 patients (21%); and bailout after balloon angioplasty, 19 patients (19%). Because of residual thrombus after stenting, 27 patients (26%) received abciximab. All patients received ticlopidin for 28 days and acetylsalicylic acid. One hundred and seventeen MS-XLs (98%) were implanted successfully. Additional (shorter) MS-II were implanted in 40 patients (39%). The stented segment length was 45 +/- 20 mm. The minimum lumen diameter increased from 0.5 +/- 0.5 mm before to 2.7 +/- 0.5 mm after stent implantation. The acute gain was 2.2 +/- 0.4 mm. Early clinical events (<4 weeks) include death, 3 (3%); subacute stent thrombosis, 1 (1%); non-Q-wave infarction, 2 (2%); CABG, 1 (1%); vascular complications, 2 (2%). Late clinical events (<6 months) include acute myocardial infarction, 5 (5%); reintervention, 6 (6%); CABG, 1 (1%). The procedural success rate was 88%, and the event free survival at 6 months was 76%. Stenting of long lesions with the MS-XL was successful and associated with an acceptable complication rate. Cathet. Cardiovasc. Intervent. 48:105-112, 1999. Copyright 1999 Wiley-Liss, Inc.

Wavenumber-4 structures observed in the low-latitude ionosphere during low and high solar activity periods using FORMOSAT/COSMIC observations

NASA Astrophysics Data System (ADS)

Onohara, Amelia Naomi; Staciarini Batista, Inez; Prado Batista, Paulo

2018-03-01

The main purpose of this study is to investigate the four-peak structure observed in the low-latitude equatorial ionosphere by the FORMOSAT/COSMIC satellites. Longitudinal distributions of NmF2 (the density of the F layer peak) and hmF2 (ionospheric F2-layer peak height) averages, obtained around September equinox periods from 2007 to 2015, were submitted to a bi-spectral Fourier analysis in order to obtain the amplitudes and phases of the main waves. The four-peak structure in the equatorial and low-latitude ionosphere was present in both low and high solar activity periods. This kind of structure possibly has tropospheric origins related to the tidal waves propagating from below that modulate the E-region dynamo, mainly the eastward non-migrating diurnal tide with wavenumber 3 (DE3, E for eastward). This wave when combined with the migrating diurnal tide (DW1, W for westward) presents a wavenumber-4 (wave-4) structure under a synoptic view. Electron densities observed during 2008 and 2013 September equinoxes revealed that the wave-4 structures became more prominent around or above the F-region altitude peak (˜ 300-350 km). The four-peak structure remains up to higher ionosphere altitudes (˜ 800 km). Spectral analysis showed DE3 and SPW4 (stationary planetary wave with wavenumber 4) signatures at these altitudes. We found that a combination of DE3 and SPW4 with migrating tides is able to reproduce the wave-4 pattern in most of the ionospheric parameters. For the first time a study using wave variations in ionospheric observations for different altitude intervals and solar cycle was done. The conclusion is that the wave-4 structure observed at high altitudes in ionosphere is related to effects of the E-region dynamo combined with transport effects in the F region.

Acute myocardial infarction associated with blood transfusion: case report and literature review.

PubMed

Velibey, Yalcin; Erbay, Aliriza; Ozkurt, Enver; Usta, Emrah; Akin, Filiz

2014-04-01

A 62-year old patient with a history of chronic anemia associated with malabsorption secondary to short gut syndrome, experienced acute chest pain the second hour after the transfusion of a crossmatch-compatible erythrocyte suspension. His electrocardiogram (ECG) revealed widespread ST-segment depressions and he had an elevated troponin level. Laboratory findings and physical examination did not indicate the presence of immunological or non-immunological blood transfusion reactions. Cardiac catheterization was performed and showed angiographically non-obstructive, atherosclerotic plaques and the absence of vasospasm or thrombus formation. Following antiischemic therapy his symptoms resolved completely. The ECG obtained 24 hours after the emergence of chest pain demonstrated normal sinus rhythm with no ST-T wave changes. We present a rare case of acute myocardial infarction induced following a blood transfusion. To the best of our knowledge, a few cases of acute myocardial infarction associated with blood transfusion have been formally recorded in the medical literature and the clinical experience regarding such cases is indeed quite limited. The present case is reviewed in the context of the relevant literature as a practical resource for clinical practice. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Recognition of incident diabetes mellitus during an acute myocardial infarction.

PubMed

Arnold, Suzanne V; Stolker, Joshua M; Lipska, Kasia J; Jones, Philip G; Spertus, John A; McGuire, Darren K; Inzucchi, Silvio E; Goyal, Abhinav; Maddox, Thomas M; Lind, Marcus; Gumber, Divya; Shore, Supriya; Kosiborod, Mikhail

2015-05-01

Diabetes mellitus (DM) is common in patients hospitalized with an acute myocardial infarction (AMI), representing in some cases the first opportunity to recognize and treat DM. We report the incidence of new DM and its recognition among patients with AMI. Patients in a 24-site US AMI registry (2005-08) had glycosylated hemoglobin assessed at a core laboratory, with results blinded to clinicians and local clinical measurements left to the discretion of the treating providers. Among 2854 AMI patients without known DM on admission, 287 patients (10%) met criteria for previously unknown DM, defined by a core laboratory glycosylated hemoglobin of ≥6.5%. Among these, 186 (65%) were unrecognized by treating clinicians, receiving neither DM education, glucose-lowering medications at discharge, nor documentation of DM in the chart (median glycosylated hemoglobin of unrecognized patients, 6.7%; range, 6.5-12.3%). Six months after discharge, only 5% of those not recognized as having DM during hospitalization had been initiated on glucose-lowering medications versus 66% of those recognized (P<0.001). Underlying DM that has not been previously diagnosed is common among AMI patients, affecting 1 in 10 patients, yet is recognized by the care team only one third of the time. Given its frequency and therapeutic implications, including but extending beyond the initiation of glucose-lowering treatment, consideration should be given to screening all AMI patients for DM during hospitalization. Inexpensive, ubiquitous, and endorsed as an acceptable screen for DM, glycosylated hemoglobin testing should be considered for this purpose. © 2015 American Heart Association, Inc.

Investigation of surface wave amplitudes in 3-D velocity and 3-D Q models

NASA Astrophysics Data System (ADS)

Ruan, Y.; Zhou, Y.

2010-12-01

It has been long recognized that seismic amplitudes depend on both wave speed structures and anelasticity (Q) structures. However, the effects of lateral heterogeneities in wave speed and Q structures on seismic amplitudes has not been well understood. We investigate the effects of 3-D wave speed and 3-D anelasticity (Q) structures on surface-wave amplitudes based upon wave propagation simulations of twelve globally-distributed earthquakes and 801 stations in Earth models with and without lateral heterogeneities in wave speed and anelasticity using a Spectral Element Method (SEM). Our tomographic-like 3-D Q models are converted from a velocity model S20RTS using a set of reasonable mineralogical parameters, assuming lateral perturbations in both velocity and Q are due to temperature perturbations. Surface-wave amplitude variations of SEM seismograms are measured in the period range of 50--200 s using boxcar taper, cosine taper and Slepian multi-tapers. We calculate ray-theoretical predictions of surface-wave amplitude perturbations due to elastic focusing, attenuation, and anelastic focusing which respectively depend upon the second spatial derivative (''roughness'') of perturbations in phase velocity, 1/Q, and the roughness of perturbations in 1/Q. Both numerical experiments and theoretical calculations show that (1) for short-period (~ 50 s) surface waves, the effects of amplitude attenuation due to 3-D Q structures are comparable with elastic focusing effects due to 3-D wave speed structures; and (2) for long-period (> 100 s) surface waves, the effects of attenuation become much weaker than elastic focusing; and (3) elastic focusing effects are correlated with anelastic focusing at all periods due to the correlation between velocity and Q models; and (4) amplitude perturbations are depend on measurement techniques and therefore cannot be directly compared with ray-theoretical predictions because ray theory does not account for the effects of measurement techniques. We calculate 3-D finite-frequency sensitivity of surface-wave amplitude to perturbations in wave speed and anelasticity (Q) which fully account for the effects of elastic focusing, attenuation, anelastic focusing as well as measurement techniques. We show that amplitude perturbations calculated using wave speed and Q sensitivity kernels agree reasonably well with SEM measurements and therefore the sensitivity kernels can be used in a joint inversion of seismic phase delays and amplitudes to simultaneously image high resolution 3-D wave speed and 3-D Q structures in the upper mantle.

Cardioprotective Effect of Coenzyme Q10 on Apoptotic Myocardial Cell Death by Regulation of Bcl-2 Gene Expression

PubMed Central

Khan, Najam Ali; Abid, M.; Ahmad, Aftab; Abuzinadah, Mohammed F.; Basheikh, Mohammed; Kishore, Kamal

2017-01-01

Objectives: To investigate the effect of coenzyme Q10 (CoQ10) on apoptotic myocardial cell death in rat model of heart ischemia and reperfusion I/R injury. Materials and Methods: Eighteen rats (200–250 g) were divided into three groups of 6 rats in each. Group I (sham-operated control group): this is the control group. The animals received the surgical procedure without IR injury or any drug treatment. Group II (I/R group): ischemia was accomplished by the occlusion of coronary artery for 30 min followed by reperfusion for 45 min and Group-III (Coenzyme Q10 treated group): Treated with CoQ10 at a dose of 1 mg/kg, postoperative for 7 days before induction of IR injury. Results: The study revealed that pretreatment with CoQ10 has shown protective effect on apoptotic rat heart and agreed with earlier reports that CoQ10 significantly protects from oxidative stress and cytopathological changes caused by cardiac ischemia followed by reperfusion and attenuated decrease of antioxidant enzymes. Nitric oxide production in the heart of ischemic rats was significantly increased by the pretreatment with CoQ10 in comparison with IR group. Conclusions: CoQ10 protects against cardiac apoptosis induced by IR injury by significantly decreasing the apoptotic DNA and regulating the expression of Bcl-2 gene. PMID:29081620

Effect of squeeze on electrostatic TG wave damping

NASA Astrophysics Data System (ADS)

Ashourvan, A.; Dubin, D. H. E.

2013-03-01

We present a 1D theory, neglecting radial dependency, for the damping of cylindrically symmetric plasma modes due to a cylindrically symmetric squeeze potential Vsq(z), applied to the axial midpoint of a non-neutral plasma column. Inside the plasma, particles experience a much smaller, Debye shielded squeeze potential φ0(z) of magnitude φs. The squeeze divides the plasma into passing and trapped particles; the latter cannot pass over the squeeze. Both analytical and computer simulation methods were used to study a 1D squeezed plasma mode. For our analytical study, in the regime where qφs/T ≪ 1, we assume the trapped particle population to be negligibly small and we treat qφ0(z) as a pertubation in the equilibrium hamiltonian. Our computer simulations consist of solving the 1D Vlasov-Poisson system and obtaining the damping rate for a self-consistent plasma mode. Damping of the mode in collisionless theory is caused by Landau resonances at energies En for which the bounce frequency ωb(En) and the wave frequency ω satisfy ω = nωb(En). Particles experience a non-sinusoidal wave potential along their bounce orbits due to the squeeze potential. As a result, the squeeze induces bounce harmonics with n ≫ 1 in the perturbed distribution. The harmonics allow resonances at energies En ≤ T and cause a substantial damping, even at wave phase velocities much larger than the thermal velocity, which is not expected for an unsqueezed plasma. In the regime ω/k≫√T/m (k is the wave number) and T ≫ qφs, the resonance damping rate has a |Vsq|2 dependence. This behavior is consistent with the observed experimental results.

The velocity of the arterial pulse wave: a viscous-fluid shock wave in an elastic tube.

PubMed

Painter, Page R

2008-07-29

The arterial pulse is a viscous-fluid shock wave that is initiated by blood ejected from the heart. This wave travels away from the heart at a speed termed the pulse wave velocity (PWV). The PWV increases during the course of a number of diseases, and this increase is often attributed to arterial stiffness. As the pulse wave approaches a point in an artery, the pressure rises as does the pressure gradient. This pressure gradient increases the rate of blood flow ahead of the wave. The rate of blood flow ahead of the wave decreases with distance because the pressure gradient also decreases with distance ahead of the wave. Consequently, the amount of blood per unit length in a segment of an artery increases ahead of the wave, and this increase stretches the wall of the artery. As a result, the tension in the wall increases, and this results in an increase in the pressure of blood in the artery. An expression for the PWV is derived from an equation describing the flow-pressure coupling (FPC) for a pulse wave in an incompressible, viscous fluid in an elastic tube. The initial increase in force of the fluid in the tube is described by an increasing exponential function of time. The relationship between force gradient and fluid flow is approximated by an expression known to hold for a rigid tube. For large arteries, the PWV derived by this method agrees with the Korteweg-Moens equation for the PWV in a non-viscous fluid. For small arteries, the PWV is approximately proportional to the Korteweg-Moens velocity divided by the radius of the artery. The PWV in small arteries is also predicted to increase when the specific rate of increase in pressure as a function of time decreases. This rate decreases with increasing myocardial ischemia, suggesting an explanation for the observation that an increase in the PWV is a predictor of future myocardial infarction. The derivation of the equation for the PWV that has been used for more than fifty years is analyzed and shown to yield predictions that do not appear to be correct. Contrary to the theory used for more than fifty years to predict the PWV, it speeds up as arteries become smaller and smaller. Furthermore, an increase in the PWV in some cases may be due to decreasing force of myocardial contraction rather than arterial stiffness.

Isolated noncompaction of myocardium associated with calcification in the interventricular septum.

PubMed

Nil, M; Mori, K; Yuasa, Y; Ichida, F

2003-01-01

We describe a 12-year-old male with isolated noncompaction of the myocardium and associated abnormal calcification in the basal interventricular septum, and we present a review of the literature. The patient has been healthy and free of symptoms. The electrocardiogram showed abnormal Q waves in III, V1, V2, and ST elevation in V1-V3. Exercise testing demonstrated ST depression in V4 and V5. Myocardial scintigraphic examination showed a regional reduction in iodine-1,2,3-beta-methyl-iodophenylpentadecanoic acid uptake in the basal interventricular septum. Since coronary angiography demonstrated normal coronary vessels and the trabeculations were not prominent in this region, we hypothesize that coronary microcirculatory dysfunction may cause subendocardial infarction associated with calcification in the same area.

Antimyosin imaging in acute transmural myocardial infarctions: results of a multicenter clinical trial.

PubMed

Johnson, L L; Seldin, D W; Becker, L C; LaFrance, N D; Liberman, H A; James, C; Mattis, J A; Dean, R T; Brown, J; Reiter, A

1989-01-01

Murine monoclonal antimyosin antibody has been shown experimentally to bind selectively to irreversibly damaged myocytes. To evaluate the safety and efficacy of monoclonal antimyosin for identifying acute transmural infarction, 50 patients with acute Q wave myocardial infarction were entered into a phase I/II multicenter trial involving three clinical sites. Indium-111 antimyosin was prepared from an instant kit formulation containing 0.5 mg of diethylene triamine pentaacetic acid (DTPA)-coupled Fab fragment (R11D10) and 1.2 to 2.4 mCi of indium-111. Average labeling efficiency was 92%. Antimyosin was injected 27 +/- 16 h after the onset of chest pain. Planar or tomographic imaging was performed 27 +/- 9 h after injection in all patients, and repeat imaging was done 24 h later in 39 patients. Of the 50 patients entered, 46 showed myocardial uptake of antimyosin (sensitivity 92%). Thirty-one of 39 planar scans performed at 24 h were diagnostic; 8 showed persistent blood pool activity that cleared by 48 h. Focal myocardial uptake of antimyosin corresponded to electrocardiographic infarct localization. No patient had an adverse reaction to antimyosin. In addition, 125 serum samples, including 21 collected greater than 42 days after injection, were tested for human antimouse antibodies, and all samples were assessed as having undetectable titers. Intensity of antimyosin uptake was correlated with infarct location and the presence or absence of collateral vessels. There was a significant correlation between faint uptake and inferoposterior infarct location. In 21 patients who had coronary angiography close to the time of antimyosin injection, there was a significant correlation between faint tracer uptake and closed infarct-related vessel with absent collateral flow.(ABSTRACT TRUNCATED AT 250 WORDS)

Myocardial viability assessed with fluorodeoxyglucose and PET in patients with Q wave myocardial infarction receiving thrombolysis: relationship to coronary anatomy and ventricular function.

PubMed

Fragasso, G; Chierchia, S L; Rossetti, E; Sciammarella, M G; Conversano, A; Lucignani, G; Landoni, C; Calori, G; Margonato, A; Fazio, F

1997-03-01

In previously thrombolysed patients, we analysed residual myocardial viability using the PET-FDG technique and correlated its presence and extent to the angiographic appearance of the infarct-related vessel and left ventricular function. Thirty-six patients who had undergone intravenous thromboloysis for acute myocardial infarction 4.8 +/- 7.2 months previously were studied. Coronary angiography, left ventriculography, and assessment of myocardial perfusion and metabolism were all performed within 1 week. All patients exhibited perfusion defects consistent with the clinically identified myocardial infarction site. Residual viability, as assessed by the PET-FDG technique, was present in 53% of cases. The infarct-related coronary artery was patent in 19 (53%) patients (TIMI grade 3, 79%); of the remaining 17 with occluded infarct-related arteries, 11 had collaterals to the infarct area. Significant FDG uptake was observed in 63% of patients with a patent infarct-related artery and in 41% of those with an occluded infarct-related artery. The same study protocol was adopted in a control group of 30 patients with myocardial infarction who did not receive thrombolysis. The number of infarct-related patent vessels was significantly lower in these patients (30 vs 53%) (TIMI grade 3, 56%), but the overall percentage of PET viability was again 53%. Qualitative analysis of the regional perfusion pattern showed that the magnitude and severity of the perfusion defect was similar in the two groups, regardless of the presence or absence of FDG uptake. Global left ventricular function was also similar in the two groups. However, regional wall motion was significantly better in the thrombolysed patients with a patent infarct-related artery than in those who had not received thrombolysis and whose culprit vessel was also patent. In conclusion, the results of our study support the notion that early recanalization of the infarct-related artery is critical for preserving left ventricular function. Although the number of patent infarct-related coronary arteries is greater and left ventricular function is better in successfully thrombolysed patients, the regional metabolic pattern does not apparently correlate with the patency of the infarct-related artery. This suggests that, in "chronic' myocardial infarction, residual tissue viability as assessed by fluorodeoxyglucose uptake does not necessarily correlate with coronary recanalization.

Global Maps of ProQ Binding In Vivo Reveal Target Recognition via RNA Structure and Stability Control at mRNA 3' Ends.

PubMed

Holmqvist, Erik; Li, Lei; Bischler, Thorsten; Barquist, Lars; Vogel, Jörg

2018-05-15

The conserved RNA-binding protein ProQ has emerged as the centerpiece of a previously unknown third large network of post-transcriptional control in enterobacteria. Here, we have used in vivo UV crosslinking and RNA sequencing (CLIP-seq) to map hundreds of ProQ binding sites in Salmonella enterica and Escherichia coli. Our analysis of these binding sites, many of which are conserved, suggests that ProQ recognizes its cellular targets through RNA structural motifs found in small RNAs (sRNAs) and at the 3' end of mRNAs. Using the cspE mRNA as a model for 3' end targeting, we reveal a function for ProQ in protecting mRNA against exoribonucleolytic activity. Taken together, our results underpin the notion that ProQ governs a post-transcriptional network distinct from those of the well-characterized sRNA-binding proteins, CsrA and Hfq, and suggest a previously unrecognized, sRNA-independent role of ProQ in stabilizing mRNAs. Copyright © 2018 Elsevier Inc. All rights reserved.

Development of a Tomography Technique for Assessment of the Material Condition of Concrete Using Optimized Elastic Wave Parameters.

PubMed

Chai, Hwa Kian; Liu, Kit Fook; Behnia, Arash; Yoshikazu, Kobayashi; Shiotani, Tomoki

2016-04-16

Concrete is the most ubiquitous construction material. Apart from the fresh and early age properties of concrete material, its condition during the structure life span affects the overall structural performance. Therefore, development of techniques such as non-destructive testing which enable the investigation of the material condition, are in great demand. Tomography technique has become an increasingly popular non-destructive evaluation technique for civil engineers to assess the condition of concrete structures. In the present study, this technique is investigated by developing reconstruction procedures utilizing different parameters of elastic waves, namely the travel time, wave amplitude, wave frequency, and Q-value. In the development of algorithms, a ray tracing feature was adopted to take into account the actual non-linear propagation of elastic waves in concrete containing defects. Numerical simulation accompanied by experimental verifications of wave motion were conducted to obtain wave propagation profiles in concrete containing honeycomb as a defect and in assessing the tendon duct filling of pre-stressed concrete (PC) elements. The detection of defects by the developed tomography reconstruction procedures was evaluated and discussed.

Field dependence of nonreciprocal magnons in chiral MnSi

NASA Astrophysics Data System (ADS)

Weber, T.; Waizner, J.; Tucker, G. S.; Georgii, R.; Kugler, M.; Bauer, A.; Pfleiderer, C.; Garst, M.; Böni, P.

2018-06-01

Spin waves in chiral magnetic materials are strongly influenced by the Dzyaloshinskii-Moriya interaction, resulting in intriguing phenomena like nonreciprocal magnon propagation and magnetochiral dichroism. Here, we study the nonreciprocal magnon spectrum of the archetypical chiral magnet MnSi and its evolution as a function of magnetic field covering the field-polarized and conical helix phase. Using inelastic neutron scattering, the magnon energies and their spectral weights are determined quantitatively after deconvolution with the instrumental resolution. In the field-polarized phase the imaginary part of the dynamical susceptibility χ''(ɛ ,q ) is shown to be asymmetric with respect to wave vectors q longitudinal to the applied magnetic field H , which is a hallmark of chiral magnetism. In the helimagnetic phase, χ''(ɛ ,q ) becomes increasingly symmetric with decreasing H due to the formation of helimagnon bands and the activation of additional spin-flip and non-spin-flip scattering channels. The neutron spectra are in excellent quantitative agreement with the low-energy theory of cubic chiral magnets with a single fitting parameter being the damping rate of spin waves.

Left bundle branch block, an old-new entity.

PubMed

Breithardt, Günter; Breithardt, Ole-Alexander

2012-04-01

Left bundle branch block (LBBB) is generally associated with a poorer prognosis in comparison to normal intraventricular conduction, but also in comparison to right bundle branch block which is generally considered to be benign in the absence of an underlying cardiac disorder like congenital heart disease. LBBB may be the first manifestation of a more diffuse myocardial disease. The typical surface ECG feature of LBBB is a prolongation of QRS above 0.11 s in combination with a delay of the intrinsic deflection in leads V5 and V6 of more than 60 ms and no septal q waves in leads I, V5, and V6 due to the abnormal septal activation from right to left. LBBB may induce abnormalities in left ventricular performance due to abnormal asynchronous contraction patterns which can be compensated by biventricular pacing (resynchronization therapy). Asynchronous electrical activation of the ventricles causes regional differences in workload which may lead to asymmetric hypertrophy and left ventricular dilatation, especially due to increased wall mass in late-activated regions, which may aggravate preexisting left ventricular pumping performance or even induce it. Of special interest are patients with LBBB and normal left ventricular dimensions and normal ejection fraction at rest but who may present with an abnormal increase in pulmonary artery pressure during exercise, production of lactate during high-rate pacing, signs of ischemia on myocardial scintigrams (but no coronary artery narrowing), and abnormal ultrastructural findings on myocardial biopsy. For this entity, the term latent cardiomyopathy had been suggested previously.

The Observational Consequences of Proton-Generated Waves at Shocks

NASA Technical Reports Server (NTRS)

Reames, Donald V.

2000-01-01

In the largest solar energetic particle (SEP) events, acceleration takes place at shock waves driven out from the Sun by fast coronal mass ejections. Protons streaming away from strong shocks generate Alfven waves that trap particles in the acceleration region, limiting outflowing intensities but increasing the efficiency of acceleration to higher energies. Early in the events, with the shock still near the Sun, intensities at 1 AU are bounded and spectra are flattened at low energies. Elements with different charge-to-mass ratios, Q/A, differentially probe the wave spectra near shocks, producing abundance ratios that vary in space and time. An initial rise in He/H, while Fe/O declines, is a typical symptom of the non-Kolmogorov wave spectra in the largest events. Strong wave generation can cause cross-field scattering near the shock and unusually rapid reduction in anisotropies even far from the shock. At the highest energies, shock spectra steepen to form a "knee." For protons, this spectral knee can vary from approx. 10 MeV to approx. 1 GeV depending on shock conditions for wave growth. In one case, the location of the knee scales approximately as Q/A in the energy/nucleon spectra of other species.

The existence of electron-acoustic shock waves and their interactions in a non-Maxwellian plasma with q-nonextensive distributed electrons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Jiu-Ning; He, Yong-Lin; Han, Zhen-Hai

2013-07-15

We present a theoretical investigation for the nonlinear interaction between electron-acoustic shock waves in a nonextensive two-electron plasma. The interaction is governed by a pair of Korteweg-de Vries-Burgers equations. We focus on studying the colliding effects on the propagation of shock waves, more specifically, we have studied the effects of plasma parameters, i.e., the nonextensive parameter q, the “hot” to “cold” electron number density ratio α, and the normalized electron kinematic viscosity η{sub 0} on the trajectory changes (phase shifts) of shock waves. It is found that there are trajectory changes (phase shifts) for both colliding shock waves in themore » present plasma system. We also noted that the nonlinearity has no decisive effect on the trajectory changes, the occurrence of trajectory changes may be due to the combined role played by the dispersion and dissipation of the nonlinear structure. Our theoretical study may be beneficial to understand the propagation and interaction of nonlinear electrostatic waves and may brings a possibility to develop the nonlinear theory of electron-acoustic waves in astrophysical plasma systems.« less

Driven phase space vortices in plasmas with nonextensive velocity distribution

NASA Astrophysics Data System (ADS)

Trivedi, Pallavi; Ganesh, Rajaraman

2017-03-01

The evolution of chirp-driven electrostatic waves in unmagnetized plasmas is numerically investigated by using a one-dimensional (1D) Vlasov-poisson solver with periodic boundary conditions. The initial velocity distribution of the 1D plasma is assumed to be governed by nonextensive q distribution [C. Tsallis, J. Stat. Phys. 52, 479 (1988)]. For an infinitesimal amplitude of an external drive, we investigate the effects of chirp driven dynamics that leads to the formation of giant phase space vortices (PSV) for both Maxwellian (q = 1) and non-Maxwellian ( q ≠ 1 ) plasmas. For non-Maxwellian plasmas, the formation of giant PSV with multiple extrema and phase velocities is shown to be dependent on the strength of "q". Novel features such as "shark"-like and transient "honeycomb"-like structures in phase space are discussed. Wherever relevant, we compare our results with previous work.

The predictive value of P-wave duration by signal-averaged electrocardiogram in acute ST elevation myocardial infarction.

PubMed

Shturman, Alexander; Bickel, Amitai; Atar, Shaul

2012-08-01

The prognostic value of P-wave duration has been previously evaluated by signal-averaged ECG (SAECG) in patients with various arrhythmias not associated with acute myocardial infarction (AMI). To investigate the clinical correlates and prognostic value of P-wave duration in patients with ST elevation AMI (STEMI). The patients (n = 89) were evaluated on the first, second and third day after admission, as well as one week and one month post-AMI. Survival was determined 2 years after the index STEMI. In comparison with the upper normal range of P-wave duration (<120 msec), the P-wave duration in STEMI patients was significantly increased on the first day (135.31 +/- 29.29 msec, P < 0.001), up to day 7 (127.17 +/- 30.02 msec, P = 0.0455). The most prominent differences were observed in patients with left ventricular ejection fraction (LVEF) < or = 40% (155.47 +/- 33.8 msec), compared to LVEF > 40% (128.79 +/- 28 msec) (P = 0.001). P-wave duration above 120 msec was significantly correlated with increased complication rate; namely, sustained ventricular tachyarrhythmia (36%), congestive heart failure (41%), atrial fibrillation (11%), recurrent angina (14%), and re-infarction (8%) (P = 0.012, odds ratio 4.267, 95% confidence interval 1.37-13.32). P-wave duration of 126 msec on the day of admission was found to have the highest predictive value for in-hospital complications including LVEF 40% (area under the curve 0.741, P < 0.001). However, we did not find a significant correlation between P-wave duration and mortality after multivariate analysis. P-wave duration as evaluated by SAECG correlates negatively with LVEF post-STEMI, and P-wave duration above 126 msec can be utilized as a non-invasive predictor of in-hospital complications and low LVEF following STEMI.

1.9 μm square-wave passively Q-witched mode-locked fiber laser.

PubMed

Ma, Wanzhuo; Wang, Tianshu; Su, Qingchao; Wang, Furen; Zhang, Jing; Wang, Chengbo; Jiang, Huilin

2018-05-14

We propose and demonstrate the operation of Q-switched mode-locked square-wave pulses in a thulium-holmium co-doped fiber laser. By using a nonlinear amplifying loop mirror, continuous square-wave dissipative soliton resonance pulse is obtained with 4.4 MHz repetition rate. With the increasing pump power, square-wave pulse duration can be broadened from 1.7 ns to 3.2 ns. On such basis Q-switched mode-locked operation is achieved by properly setting the pump power and the polarization controllers. The internal mode-locked pulses in Q-switched envelope still keep square-wave type. The Q-switched repetition rate can be varied from 41.6 kHz to 74 kHz by increasing pump power. The corresponding average single-pulse energy increases from 2.67 nJ to 5.2 nJ. The average peak power is also improved from 0.6 W to 1.1 W when continuous square-wave operation is changed into Q-switched mode-locked operation. It indicates that Q-switched mode-locked operation is an effective method to increase the square-wave pulse energy and peak power.

Discordant U waves in the setting of hyperkalaemia.

PubMed

Chhabra, Lovely; Spodick, David H

2013-07-04

Physiological U wave genesis occurs likely secondary to either late repolarisation of Purkinje fibres, or late repolarisation of some myocardial cells and/or delayed after depolarisation of the ventricular wall occurring during ventricular filling. Hypokalaemia has a well-known association with pathological 'U wave' which actually combines with the T wave (TU complex) and results from slowing of phase 3 of the action potential with resultant electrical interaction between the three myocardial layers. U waves usually tend to disappear in the setting of hyperkalaemia. We report an unusual case where hyperkalaemia and discordant U waves coexisted. We believe that this may have occurred as a result of partial clinical adaptation of cardiac myocytes to the long-standing effects of hyperkalaemia as the patient had underlying history of chronic kidney disease. We also discuss the possible mechanisms of the U wave genesis and the importance of different U wave morphologies encountered in the real clinical practice.

Overcoming Heparin-Associated RT-qPCR Inhibition and Normalization Issues for microRNA Quantification in Patients with Acute Myocardial Infarction.

PubMed

Coelho-Lima, Jose; Mohammed, Ashfaq; Cormack, Suzanne; Jones, Samuel; Das, Rajiv; Egred, Mohaned; Panahi, Pedram; Ali, Simi; Spyridopoulos, Ioakim

2018-06-11

 Cardiac-enriched micro ribonucleic acids (miRNAs) are released into the circulation following ST-elevation myocardial infarction (STEMI). Lack of standardized approaches for reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) data normalization and presence of RT-qPCR inhibitors (e.g. heparin) in patient blood samples have prevented reproducible miRNA quantification in this cohort and subsequent translation of these biomarkers to clinical practice.  Using a RT-qPCR miRNA screening platform, we identified and validated an endogenous circulating miRNA as a normalization control. In addition, we assessed the effects of in vivo and in vitro anticoagulant drugs administration (heparin and bivalirudin) on three RT-qPCR normalization strategies (global miRNA mean, exogenous spike-in control [cel-miR-39] and endogenous miRNA control). Finally, we evaluated the effect of heparin and its in vitro inhibition with heparinase on the quantification of cardiac-enriched miRNAs in STEMI patients.  miR-425-5p was validated as an endogenous miRNA control. Heparin administration in vitro and in vivo inhibited all RT-qPCR normalization strategies. In contrast, bivalirudin had no effects on cel-miR-39 or miR-425-5p quantification. In vitro RNA sample treatment with 0.3 U of heparinase overcame heparin-induced over-estimation of cardiac-enriched miRNA levels and improved their correlation with high-sensitivity troponin T.  miRNA quantification in STEMI patients receiving heparin is jeopardized by its effect on all RT-qPCR normalization approaches. Use of samples from bivalirudin-treated patients or in vitro treatment of heparin-contaminated samples with heparinase are suitable alternatives for miRNA quantification in this cohort. Finally, we reinforce the evidence that cardiac-enriched miRNAs early after myocardial reperfusion reflect the severity of cardiac injury. Schattauer GmbH Stuttgart.

Absorption band Q model for the Earth

NASA Technical Reports Server (NTRS)

Anderson, D. L.; Given, J. W.

1981-01-01

Attenuation in solids and liquids, as measured by the quality factor Q, is typically frequency dependent. In seismology, however, Q is usually assumed to be independent of frequency. Body wave, surface wave, and normal mode data are used to place constraints on the frequency dependence of Q in the mantle. Specific features of the absorption band model are: low-Q in the seismic band at both the top and the base of the mantle, low-Q for long-period body waves in the outer core, an inner core Q sub s that increases with period, and low Q sub p/Q sub s at short periods in the middle mantle.

Exercise-induced ST-segment elevation during treadmill exercise testing.

PubMed

Patanè, Salvatore; Marte, Filippo

2010-09-03

The exercise electrocardiogram is a commonly used non-invasive and inexpensive method for detection of electrocardiogram (ECG) changes secondary to myocardial ischemia. It has been reported that in patients with a first myocardial infarction and without residual ischemia, exercise-induced ST-segment elevation in Q leads is related to a more damaged coronary microcirculation and to less viable myocardium. Exercise-induced ST-segment elevation is a rare phenomenon in patients without prior myocardial infarction. When occurring purely during exercise, coronary lesions are frequent and often severe, and on the other hand ST-segment elevation of the recovery phase is frequently associated with normal arteries or less severe lesions. We present a case of exercise-induced ST-segment elevation in a 51-year-old Italian man. Coronary angiography revealed a significant left anterior descending coronary artery stenosis, a significant circumflex coronary artery stenosis, a significant first obtuse marginal coronary artery stenosis and a significant second obtuse marginal coronary artery stenosis. Percutaneous transluminal coronary angioplasty with implantation of stents was successfully performed. Also this case is illustrative of the rare phenomenon of exercise-induced ST-segment elevation. Copyright © 2008 Elsevier B.V. All rights reserved.

Non-Fermi surface nesting driven commensurate magnetic ordering in Fe-doped S r 2 Ru O 4

DOE PAGES

Zhu, M.; Shanavas, K. V.; Wang, Y.; ...

2017-02-10

Sr 2RuO 4, an unconventional superconductor, is known to possess an incommensurate spin-density wave instability driven by Fermi surface nesting. Here we report a static spin-density wave ordering with a commensurate propagation vector q c = (0.250.250) in Fe-doped Sr 2RuO 4, despite the magnetic fluctuations persisting at the incommensurate wave vectors q ic = (0.30.3L) as in the parent compound. The latter feature is corroborated by the first-principles calculations, which show that Fe substitution barely changes the nesting vector of the Fermi surface. Finally, these results suggest that in addition to the known incommensurate magnetic instability, Sr 2RuO 4more » is also in proximity to a commensurate magnetic tendency that can be stabilized via Fe doping.« less

Itinerant density wave instabilities at classical and quantum critical points

DOE PAGES

Feng, Yejun; van Wezel, Jasper; Wang, Jiyang; ...

2015-07-27

Charge ordering in metals is a fundamental instability of the electron sea, occurring in a host of materials and often linked to other collective ground states such as superconductivity. What is difficult to parse, however, is whether the charge order originates among the itinerant electrons or whether it arises from the ionic lattice. Here in this study we employ high-resolution X-ray diffraction, combined with high-pressure and low-temperature techniques and theoretical modelling, to trace the evolution of the ordering wavevector Q in charge and spin density wave systems at the approach to both thermal and quantum phase transitions. The non-monotonic behaviourmore » of Q with pressure and the limiting sinusoidal form of the density wave point to the dominant role of the itinerant instability in the vicinity of the critical points, with little influence from the lattice. Fluctuations rather than disorder seem to disrupt coherence.« less

Electro-optic Q-switch

NASA Technical Reports Server (NTRS)

Zou, Yingyin (Inventor); Chen, Qiushui (Inventor); Zhang, Run (Inventor); Jiang, Hua (Inventor)

2006-01-01

An electro-optic Q-switch for generating sequence of laser pulses was disclosed. The Q-switch comprises a quadratic electro-optic material and is connected with an electronic unit generating a radio frequency wave with positive and negative pulses alternatively. The Q-switch is controlled by the radio frequency wave in such a way that laser pulse is generated when the radio frequency wave changes its polarity.

Experimental Myocardial Infarction Upregulates Circulating Fibroblast Growth Factor-23.

PubMed

Andrukhova, Olena; Slavic, Svetlana; Odörfer, Kathrin I; Erben, Reinhold G

2015-10-01

Myocardial infarction (MI) is a major cause of death worldwide. Epidemiological studies have linked vitamin D deficiency to MI incidence. Because fibroblast growth factor-23 (FGF23) is a master regulator of vitamin D hormone production and has been shown to be associated with cardiac hypertrophy per se, we explored the hypothesis that FGF23 may be a previously unrecognized pathophysiological factor causally linked to progression of cardiac dysfunction post-MI. Here, we show that circulating intact Fgf23 was profoundly elevated, whereas serum vitamin D hormone levels were suppressed, after induction of experimental MI in rat and mouse models, independent of changes in serum soluble Klotho or serum parathyroid hormone. Both skeletal and cardiac expression of Fgf23 was increased after MI. Although the molecular link between the cardiac lesion and circulating Fgf23 concentrations remains to be identified, our study has uncovered a novel heart-bone-kidney axis that may have important clinical implications and may inaugurate the new field of cardio-osteology. © 2015 American Society for Bone and Mineral Research.

A dual-mode highly efficient class-E stimulator controlled by a low-Q class-E power amplifier through duty cycle.

PubMed

Chiu, Hung-Wei; Lu, Chien-Chi; Chuang, Jia-min; Lin, Wei-Tso; Lin, Chii-Wann; Kao, Ming-Chien; Lin, Mu-Lien

2013-06-01

This paper presents the design flow of two high-efficiency class-E amplifiers for the implantable electrical stimulation system. The implantable stimulator is a high-Q class-E driver that delivers a sine-wave pulsed radiofrequency (PRF) stimulation, which was verified to have a superior efficacy in pain relief to a square wave. The proposed duty-cycle-controlled class-E PRF driver designed with a high-Q factor has two operational modes that are able to achieve 100% DC-AC conversion, and involves only one switched series inductor and an unchanged parallel capacitor. The measured output amplitude under low-voltage (LV) mode using a 22% duty cycle was 0.98 V with 91% efficiency, and under high-voltage (HV) mode using a 47% duty cycle was 2.95 V with 92% efficiency. These modes were inductively controlled by a duty-cycle detector, which can detect the duty-cycle modulated signal generated from the external complementary low-Q class-E power amplifier (PA). The design methodology of the low-Q inductive interface for a non-50% duty cycle is presented. The experimental results exhibits that the 1.5-V PA that consumes DC power of 14.21 mW was able to deliver a 2.9-V sine wave to a 500 Ω load. The optimal 60% drain efficiency of the system from the PA to the load was obtained at a 10-mm coupling distance.

Crustal attenuation characteristics in western Turkey

NASA Astrophysics Data System (ADS)

Kurtulmuş, Tevfik Özgür; Akyol, Nihal

2013-11-01

We analysed 1764 records produced by 322 micro- and moderate-size local earthquakes in western Turkey to estimate crustal attenuation characteristics in the frequency range of 1.0 ≤ f ≤ 10 Hz. In the first step, we obtained non-parametric attenuation functions and they show that seismic recordings of transverse and radial S waves exhibit different characteristics at short and long hypocentral distances. Applying a two-step inversion, we parametrized Q( f ) and geometrical spreading exponent b( f ) for the entire distance range between 10 and 200 km and then we estimated separately Q and b values for short (10-70 km) and large (120-200 km) distance ranges. We could not observe significant frequency dependencies of b for short distance range, whereas the significant frequency dependence of b was observed for large distances. Low Q0 values (˜60) with strong frequency dependence of Q (˜1.4) for short distances suggest that scattering might be an important factor contributing to the attenuation of body waves in the region, which could be associated to a high degree of fracturing, fluid filled cracks, young volcanism and geothermal activity in the crust. Weak Q frequency dependence and higher Q0 values for large distances manifest more homogenous medium because of increasing pressure and enhanced healing of cracks with increasing temperature and depth. Q anisotropy was also observed for large hypocentral distance ranges.

Mapping the Active Site Helix-to-Strand Conversion of CxxxxC Peroxiredoxin Q Enzymes †

PubMed Central

Perkins, Arden; Gretes, Michael C.; Nelson, Kimberly J.; Poole, Leslie B.; Karplus, P. Andrew

2012-01-01

Peroxiredoxins (Prx) are a family of enzymes which reduce peroxides using a peroxidatic cysteine residue; among these, the PrxQ subfamily members are proposed to be the most ancestral-like yet are among the least characterized. In many PrxQ enzymes, a second “resolving” cysteine is located six residues downstream from the peroxidatic Cys, and these residues form a disulfide during the catalytic cycle. Here, we describe three hyperthermophilic PrxQ crystal structures originally solved by the RIKEN structural genomics group. We reprocessed the diffraction data and carried out further refinement to yield models with Rfree lowered by 2.3–7.2% and resolution extended by 0.2–0.3 Å, making one, at 1.4 Å, the best resolved peroxiredoxin to date. Comparisons of two matched thiol and disulfide forms reveal that the active site conformational change required for disulfide formation involves a transition of about 20 residues from a pair of α-helices to a β-hairpin and 310-helix. Each conformation has about 10 residues with high disorder providing slack that enables the dramatic shift, and the two conformations are anchored to the protein core by distinct non-polar side chains that fill three hydrophobic pockets. Sequence conservation patterns confirm the importance of these and a few additional residues for function. From a broader perspective, this study raises the provocative question of how to make use of the valuable information in the protein data bank generated by structural genomics projects but not described in the literature, perhaps remaining unrecognized and certainly underutilized. PMID:22928725

Marginal instability threshold of magnetosonic waves in kappa distributed plasma

NASA Astrophysics Data System (ADS)

Bashir, M. F.; Manzoor, M. Z.; Ilie, R.; Yoon, P. H.; Miasli, M. S.

2017-12-01

The dispersion relation of magnetosonic wave is studied taking the non-extensive anisotropic counter-streaming distribution which follows the Tsallis statistics. The effects of non-extensivity parameter (q), counter-streaming parameter (P) and the wave-particle interaction is analyzed on the growth rate and the marginal instability threshold condition of Magnetosonic (MS) mode to provide the possible explanation of different regions the Bale-diagram obtained from the solar wind data at 1 AU as represented by the temperature anisotropy ( ) vs plasma beta ( ) solar wind data plot. It is shown that the most of the regions of Bale-diagram is bounded by the MS instability under different condition and best fitted by the non-extesnive distribution. The results for the bi-kappa distribution and bi- Maxwellian distribution are also obtained in the limits and respectively.

Normal computerized Q wave measurements in healthy young athletes.

PubMed

Saini, Divakar; Grober, Aaron F; Hadley, David; Froelicher, Victor

Recent Expert consensus statements have sought to decrease false positive rates of electrocardiographic abnormalities requiring further evaluation when screening young athletes. These statements are largely based on traditional ECG patterns and have not considered computerized measurements. To define the normal limits for Q wave measurements from the digitally recorded ECGs of healthy young athletes. All athletes were categorized by sex and level of participation (high school, college, and professional), and underwent screening ECGs with routine pre-participation physicals, which were electronically captured and analyzed. Q wave amplitude, area and duration were recorded for athletes with Q wave amplitudes greater than 0.5mm at standard paper amplitude display (1mV/10mm). ANOVA analyses were performed to determine differences these parameters among all groups. A positive ECG was defined by our Stanford Computerized Criteria as exceeding the 99th percentile for Q wave area in 2 or more leads. Proportions testing was used to compare the Seattle Conference Q wave criteria with our data-driven criteria. 2073 athletes in total were screened. Significant differences in Q wave amplitude, duration and area were identified both by sex and level of participation. When applying our Stanford Computerized Criteria and the Seattle criteria to our cohort, two largely different groups of athletes are identified as having abnormal Q waves. Computer analysis of athletes' ECGs should be included in future studies that have greater numbers, more diversity and adequate end points. Copyright © 2017 Elsevier Inc. All rights reserved.

Attenuation Characteristics of High Frequency Seismic Waves in Southern India

NASA Astrophysics Data System (ADS)

Sivaram, K.; Utpal, Saikia; Kanna, Nagaraju; Kumar, Dinesh

2017-07-01

We present a systematic study of seismic attenuation and its related Q structure derived from the spectral analysis of P-, S-waves in the southern India. The study region is separated into parts of EDC (Eastern Dharwar Craton), Western Dharwar Craton (WDC) and Southern Granulite Terrain (SGT). The study is carried out in the frequency range 1-20 Hz, using a single-station spectral ratio technique. We make use of about 45 earthquakes, recorded in a network of about 32 broadband 3-component seismograph-stations, having magnitudes ( M L) varying from 1.6 to 4.5, to estimate the average seismic body wave attenuation quality factors; Q P and Q S. Their estimated average values are observed to be fitting to the power law form of Q = Q 0 f n . The averaged power law relations for Southern Indian region (as a whole) are obtained as Q P = (95 ± 1.12) f (1.32±0.01); Q S = (128 ± 1.84) f (1.49±0.01). Based on the stations and recorded local earthquakes, for parts of EDC, WDC and SGT, the average power law estimates are obtained as: Q P = (97 ± 5) f (1.40±0.03), Q S = (116 ± 1.5) f (1.48±0.01) for EDC region; Q P = (130 ± 7) f (1.20±0.03), Q S = (103 ± 3) f (1.49±0.02) for WDC region; Q P = (68 ± 2) f (1.4±0.02), Q S = (152 ± 6) f (1.48±0.02) for SGT region. These estimates are weighed against coda Q ( Q C) estimates, using the coda decay technique, which is based on a weak backscattering of S-waves. A major observation in the study of body wave analysis is the low body wave Q ( Q 0 < 200), moderately high value of the frequency-exponent, ` n' (>0.5) and Q S/ Q P ≫ 1, suggesting lateral stretches of dominant scattering mode of seismic wave propagation. This primarily could be attributed to possible thermal anomalies and spread of partially fluid-saturated rock-masses in the crust and upper mantle of the southern Indian region, which, however, needs further laboratory studies. Such physical conditions might partly be correlated to the active seismicity and intraplate tectonism, especially in SGT and EDC regions, as per the observed low- Q P and Q S values. Additionally, the enrichment of coda waves and significance of scattering mechanisms is evidenced in our observation of Q C > Q S estimates. Lapse time study shows Q C values increasing with lapse time. High Q C values at 40 s lapse times in WDC indicate that it may be a relatively stable region. In the absence of detailed body wave attenuation studies in this region, the frequency dependent Q relationships developed here are useful for the estimation of earthquake source parameters of the region. Also, these relations may be used for the simulation of earthquake strong ground motions which are required for the estimation of seismic hazard, geotechnical and retrofitting analysis of critical structures in the region.

A Q-Band Free-Space Characterization of Carbon Nanotube Composites

PubMed Central

Hassan, Ahmed M.; Garboczi, Edward J.

2016-01-01

We present a free-space measurement technique for non-destructive non-contact electrical and dielectric characterization of nano-carbon composites in the Q-band frequency range of 30 GHz to 50 GHz. The experimental system and error correction model accurately reconstruct the conductivity of composite materials that are either thicker than the wave penetration depth, and therefore exhibit negligible microwave transmission (less than −40 dB), or thinner than the wave penetration depth and, therefore, exhibit significant microwave transmission. This error correction model implements a fixed wave propagation distance between antennas and corrects the complex scattering parameters of the specimen from two references, an air slab having geometrical propagation length equal to that of the specimen under test, and a metallic conductor, such as an aluminum plate. Experimental results were validated by reconstructing the relative dielectric permittivity of known dielectric materials and then used to determine the conductivity of nano-carbon composite laminates. This error correction model can simplify routine characterization of thin conducting laminates to just one measurement of scattering parameters, making the method attractive for research, development, and for quality control in the manufacturing environment. PMID:28057959

Positive T wave in lead aVR as an independent predictor for 1-year major adverse cardiac events in patients with first anterior wall ST-segment elevation myocardial infarction.

PubMed

Kobayashi, Akihiro; Misumida, Naoki; Aoi, Shunsuke; Kanei, Yumiko

2017-11-01

Positive T wave in lead aVR has been shown to predict an adverse in-hospital outcome in patients with anterior wall ST-segment elevation myocardial infarction (STEMI). However, the prognostic value of positive T wave in lead aVR on a long-term outcome has not been fully explored. We performed a retrospective analysis of 190 consecutive patients with first anterior wall STEMI who underwent an emergent coronary angiogram. Patients were divided into those with positive T wave > 0 mV and those with negative T wave ≦ 0 mV in lead aVR. Baseline and angiographic characteristics, and in-hospital revascularization procedures were recorded. In addition, in-hospital and 1-year major adverse cardiac events (MACE) including death, recurrent myocardial infarction, and target vessel revascularization were recorded. Among 190 patients, 37 patients (19%) had positive T wave and 153 patients (81%) had negative T wave in lead aVR. Patients with positive T wave had higher rate of left main disease defined as stenosis ≥50% (11% vs. 2%, p = .028) than those with negative T wave. Patients with positive T wave had higher rate of 1-year MACE (38% vs. 13%, p < .001) driven by higher all-cause mortality (27% vs. 5%, p < .001). Positive T wave was an independent predictor for 1-year MACE (OR 2.74; 95% CI 1.04-7.15; p = .04). Positive T wave in lead aVR was an independent predictor for 1-year MACE in patients with first anterior wall STEMI. © 2017 Wiley Periodicals, Inc.

Effect of sound on gap-junction-based intercellular signaling: Calcium waves under acoustic irradiation.

PubMed

Deymier, P A; Swinteck, N; Runge, K; Deymier-Black, A; Hoying, J B

2015-01-01

We present a previously unrecognized effect of sound waves on gap-junction-based intercellular signaling such as in biological tissues composed of endothelial cells. We suggest that sound irradiation may, through temporal and spatial modulation of cell-to-cell conductance, create intercellular calcium waves with unidirectional signal propagation associated with nonconventional topologies. Nonreciprocity in calcium wave propagation induced by sound wave irradiation is demonstrated in the case of a linear and a nonlinear reaction-diffusion model. This demonstration should be applicable to other types of gap-junction-based intercellular signals, and it is thought that it should be of help in interpreting a broad range of biological phenomena associated with the beneficial therapeutic effects of sound irradiation and possibly the harmful effects of sound waves on health.

Non-ST-elevation acute coronary syndrome in the elderly: treatment strategies and 30-day outcome.

PubMed

De Servi, Stefano; Cavallini, Claudio; Dellavalle, Antonio; Santoro, Giovanni Maria; Bonizzoni, Erminio; Marzocchi, Antonio; Politi, Alessandro; Pesaresi, Antonio; Mariani, Matteo; Chierchia, Sergio

2004-05-01

The purpose of this study was to assess the current care of elderly patients with non-ST-elevation acute coronary syndrome (ACS), with particular regard to the rate of use of antiplatelet drugs and the type of strategy, aggressive or conservative, in a population of consecutive patients admitted to 76 Coronary Care Units in Italy. Prospective registry of patients admitted to Coronary Care Units with a diagnosis of non-ST-elevation ACS during a 2-month period. Thirty-day follow-up was available in all patients. Of 1581 patients enrolled in the registry, 564 were 75 years or older. As compared with the 1017 younger patients, elderly patients had a greater prevalence of female sex (42% vs 27%, P <.001), hypertension (70% vs 59%, P <.001), prior myocardial infarction (MI) (41% vs 29%, P <.001), prior angina (18% vs 13%, P <.01), prior use of aspirin (49% vs 39%, P <.001), ST-segment depression (54% vs 43%, P <.001), and troponin positivity (66% vs 59%, P <.05). The higher-risk profile of elderly patients was confirmed by the greater number of patients with a high TIMI risk score (37% vs 22%, P <.001). GPIIb/IIIa inhibitors were less frequently used in elderly patients (P <.05). An aggressive strategy (coronary arteriography within 4 days of admission, followed by revascularization, if feasible) was adopted in 39% elderly patients and in 56% younger patients (P <.001). An interventional procedure within 30 days was performed in 30% of elderly patients and 48% of younger patients (P <.001). Elderly patients had a more unfavorable 30-day outcome compared with younger ones, as shown by the higher rates of death (6.4% vs 1.7%), acute myocardial infarction (7.1% vs 5%), and stroke (1.3% vs 0.5%). Multivariate analysis of the elderly group identified a conservative strategy (OR, 2.31; 95% CI, 1.20 to 4.48) and a diagnosis of non-Q-wave MI (OR, 2.27; 95% CI, 1.32 to 3.93) as independent predictors of 30-day events. The elderly represent a very high-risk subgroup among patients with non-ST-elevation ACS, with a nearly 4-fold as high 30-day death rate as that of younger patients. These data call for a greater attention to such population, both in terms of an improved representation in clinical research and of the assessment of the outcome of different strategies in appropriately designed randomized trials.

Effects of atorvastatin on early recurrent ischemic events in acute coronary syndromes: the MIRACL study: a randomized controlled trial.

PubMed

Schwartz, G G; Olsson, A G; Ezekowitz, M D; Ganz, P; Oliver, M F; Waters, D; Zeiher, A; Chaitman, B R; Leslie, S; Stern, T

2001-04-04

Patients experience the highest rate of death and recurrent ischemic events during the early period after an acute coronary syndrome, but it is not known whether early initiation of treatment with a statin can reduce the occurrence of these early events. To determine whether treatment with atorvastatin, 80 mg/d, initiated 24 to 96 hours after an acute coronary syndrome, reduces death and nonfatal ischemic events. A randomized, double-blind trial conducted from May 1997 to September 1999, with follow-up through 16 weeks at 122 clinical centers in Europe, North America, South Africa, and Australasia. A total of 3086 adults aged 18 years or older with unstable angina or non-Q-wave acute myocardial infarction. Patients were stratified by center and randomly assigned to receive treatment with atorvastatin (80 mg/d) or matching placebo between 24 and 96 hours after hospital admission. Primary end point event defined as death, nonfatal acute myocardial infarction, cardiac arrest with resuscitation, or recurrent symptomatic myocardial ischemia with objective evidence and requiring emergency rehospitalization. A primary end point event occurred in 228 patients (14.8%) in the atorvastatin group and 269 patients (17.4%) in the placebo group (relative risk [RR], 0.84; 95% confidence interval [CI], 0.70-1.00; P =.048). There were no significant differences in risk of death, nonfatal myocardial infarction, or cardiac arrest between the atorvastatin group and the placebo group, although the atorvastatin group had a lower risk of symptomatic ischemia with objective evidence and requiring emergency rehospitalization (6.2% vs 8.4%; RR, 0.74; 95% CI, 0.57-0.95; P =.02). Likewise, there were no significant differences between the atorvastatin group and the placebo group in the incidence of secondary outcomes of coronary revascularization procedures, worsening heart failure, or worsening angina, although there were fewer strokes in the atorvastatin group than in the placebo group (12 vs 24 events; P =.045). In the atorvastatin group, mean low-density lipoprotein cholesterol level declined from 124 mg/dL (3.2 mmol/L) to 72 mg/dL (1.9 mmol/L). Abnormal liver transaminases (>3 times upper limit of normal) were more common in the atorvastatin group than in the placebo group (2.5% vs 0.6%; P<.001). For patients with acute coronary syndrome, lipid-lowering therapy with atorvastatin, 80 mg/d, reduces recurrent ischemic events in the first 16 weeks, mostly recurrent symptomatic ischemia requiring rehospitalization.

Infarct-like acute myocarditis: relation between electrocardiographic findings and myocardial damage as assessed by cardiac magnetic resonance imaging.

PubMed

Nucifora, Gaetano; Miani, Daniela; Di Chiara, Antonio; Piccoli, Gianluca; Artico, Jessica; Puppato, Michela; Slavich, Gianaugusto; De Biasio, Marzia; Gasparini, Daniele; Proclemer, Alessandro

2013-03-01

Acute myocarditis (AM) may occasionally have an infarct-like presentation. The aim of the present study was to investigate the relation between electrocardiographic (ECG) findings in this group of patients and myocardial damage assessed by cardiac magnetic resonance imaging (MRI) with the late gadolinium enhancement (LGE) technique. Myocardial damage may be associated with ECG changes in infarct-like AM. Forty-one consecutive patients (36 males; mean age, 36 ± 12 years) with diagnosis of AM according to cardiac MRI Lake Louise criteria and infarct-like presentation were included. The relation between site of ST-segment elevation (STE), sum of STE (sumSTE), time to normalization of STE, and development of negative T wave with the extent of LGE (expressed as % of left ventricular mass [%LV LGE]), was evaluated. Most (80%) patients presented with inferolateral STE; mean sumSTE was 5 ± 3 mm. Normalization of STE occurred within 24 hours in 20 (49%) patients. Development of negative T wave occurred in 28 (68%) patients. Cardiac MRI showed LGE in all patients; mean %LV LGE was 9.6 ± 7.2%. Topographic agreement between site of STE and LGE was 68%. At multivariate analysis, sumSTE (β = 0.42, P < 0.001), normalization of STE >24 hours (β = 0.39, P < 0.001), and development of negative T wave (β = 0.49, P < 0.001) were independently related to %LV LGE. Analysis of the site of STE underestimates the extent of myocardial injury among patients with infarct-like myocarditis. However, some ECG features (ie, sumSTE, normalization of STE >24 hours, and development of negative T wave) may help to identify patients with larger areas of myocardial damage. © 2012 Wiley Periodicals, Inc.

Relation of Post-Coronary Artery Bypass Graft Creatine Kinase-MB Elevations and New Q Waves With Long-Term Cardiovascular Death in Patients With Diabetes Mellitus and Multivessel Coronary Artery Disease.

PubMed

Domanski, Michael; Farkouh, Michael E; Zak, Victor; French, John; Alexander, John H; Bochenek, Andrzej; Hamon, Martial; Mahaffey, Kenneth; Puskas, John; Smith, Peter; Shrader, Peter; Fuster, Valentin

2016-12-01

Associations of early creatine phosphokinase-MB (CK-MB) elevation and new Q waves and their association with cardiovascular death (CVD) after coronary artery bypass grafting (CABG) have been reported, but this association has not been studied in a large population of patients with diabetes mellitus. In this study, we examine the association of periprocedural CK-MB elevations and new Q waves with CVD in the Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease trial. Cox proportional hazards regression was used to assess the relation of CK-MB elevations and new Q waves in the first 24 hours after procedure and their relation to CVD; logistic regression was used to assess odds ratios of these variables. Hazard ratios, 95% confidence intervals, and p values associated with Wald chi-square test are reported. CK-MB elevation in first 24 hours after procedure was independently associated with CVD. CVD hazard increased by 6% (p <0.001) with each multiple of CK-MB above the upper reference limit (URL); odds of new post-CABG Q waves increased by a factor of 1.08 (p <0.001); at 7× CK-MB URL, HR was >2. CK-MB URL multiples of 7, 12, and 15 were associated with new Q-wave odds ratios of 9, 16, and 27 times, respectively (p ≤0.001, C-statistic >0.70). New Q waves were independently associated with survival in the multivariate model only when CK-MB was excluded (p = 0.01). In conclusion, independent associations included (1) CVD and early post-CABG CK-MB elevation; (2) new Q waves with early post-CABG CK-MB elevation; (3) CVD with new Q waves only when CK-MB elevation is excluded from analysis. Copyright © 2016 Elsevier Inc. All rights reserved.

Thermodynamics properties study of diatomic molecules with q-deformed modified Poschl-Teller plus Manning Rosen non-central potential in D dimensions using SUSYQM approach

NASA Astrophysics Data System (ADS)

Suparmi, A.; Cari, C.; Pratiwi, B. N.

2016-04-01

D-dimensional Dirac equation of q-deformed modified Poschl-Teller plus Manning Rosen non-central potential was solved using supersymmetric quantum mechanics (SUSY QM). The relativistic energy spectra were analyzed by using SUSY QM and shape invariant properties from radial part of D dimensional Dirac equation and the angular quantum numbers were obtained from angular part of D dimensional Dirac equation. The SUSY operators was used to generate the D dimensional relativistic wave functions both for radial and angular parts. In the non-relativistic limit, the relativistic energy equation was reduced to the non-relativistic energy. In the classical limit, the partition function of vibrational, the specific heat of vibrational, and the mean energy of vibrational of some diatomic molecules were calculated from the equation of non-relativistic energy with the help of error function and Mat-lab 2011.

Deeply reinverted T wave at 14 days after the onset of first anterior acute myocardial infarction predicts improved left ventricular function at 6 months.

PubMed

Yokoyama, Hiroaki; Tomita, Hirofumi; Nishizaki, Fumie; Hanada, Kenji; Shibutani, Shuji; Yamada, Masahiro; Abe, Naoki; Higuma, Takumi; Osanai, Tomohiro; Okumura, Ken

2015-03-01

Changes in electrocardiogram (ECG), especially in the ST segment and T wave, have been recognized as a noninvasive diagnostic tool for coronary flow or myocardial injury. A deeply inverted T wave at 14 days after successful percutaneous coronary intervention (PCI) in patients with ST-segment elevation acute myocardial infarction (STEMI) predicts improved left ventricular (LV) function at 6 months. We enrolled 112 consecutive patients (88 men, 63 ± 11 years) with first anterior STEMI who underwent successful PCI. A 12-lead ECG was recorded everyday from admission through 14 days. After PCI, the first T-wave inversion was observed within 2 days, and the second occurred at 14 days. We measured the maximum depth of the reinverted T wave (Neg-T) and divided the patients into 2 groups based on the median value of Neg-T: the deep group (≥0.6 mV, n = 62) and the nondeep group (<0.6 mV, n = 50). LV ejection fraction (LVEF) at 14 days did not differ between the 2 groups, but it was greater in the deep than in the nondeep group at 6 months (50.0% ± 8.8% vs 42.5% ± 9.8 %, P < 0.0001). The maximum creatinine phosphokinase-myocardial band (CPK-MB) value was significantly lower in the deep than in the nondeep group. Reappearance of the R wave in precordial leads at 6 months was more frequently observed in the deep than in the nondeep group (68% vs 46%, P = 0.02). Multivariate regression analysis showed that the Neg-T and max CPK-MB were independent contributors to LVEF at 6 months. A deeply reinverted T wave at 14 days after onset of first anterior STEMI can be a useful predictive marker for improved LV function at 6 months. © 2015 Wiley Periodicals, Inc.

Kaempferol increases levels of coenzyme Q in kidney cells and serves as a biosynthetic ring precursor.

PubMed

Fernández-Del-Río, Lucía; Nag, Anish; Gutiérrez Casado, Elena; Ariza, Julia; Awad, Agape M; Joseph, Akil I; Kwon, Ohyun; Verdin, Eric; de Cabo, Rafael; Schneider, Claus; Torres, Jorge Z; Burón, María I; Clarke, Catherine F; Villalba, José M

2017-09-01

Coenzyme Q (Q) is a lipid-soluble antioxidant essential in cellular physiology. Patients with Q deficiencies, with few exceptions, seldom respond to treatment. Current therapies rely on dietary supplementation with Q 10 , but due to its highly lipophilic nature, Q 10 is difficult to absorb by tissues and cells. Plant polyphenols, present in the human diet, are redox active and modulate numerous cellular pathways. In the present study, we tested whether treatment with polyphenols affected the content or biosynthesis of Q. Mouse kidney proximal tubule epithelial (Tkpts) cells and human embryonic kidney cells 293 (HEK 293) were treated with several types of polyphenols, and kaempferol produced the largest increase in Q levels. Experiments with stable isotope 13 C-labeled kaempferol demonstrated a previously unrecognized role of kaempferol as an aromatic ring precursor in Q biosynthesis. Investigations of the structure-function relationship of related flavonols showed the importance of two hydroxyl groups, located at C3 of the C ring and C4' of the B ring, both present in kaempferol, as important determinants of kaempferol as a Q biosynthetic precursor. Concurrently, through a mechanism not related to the enhancement of Q biosynthesis, kaempferol also augmented mitochondrial localization of Sirt3. The role of kaempferol as a precursor that increases Q levels, combined with its ability to upregulate Sirt3, identify kaempferol as a potential candidate in the design of interventions aimed on increasing endogenous Q biosynthesis, particularly in kidney. Copyright © 2017 Elsevier Inc. All rights reserved.

Timing of left heart base descent in dogs with dilated cardiomyopathy and normal dogs.

PubMed

Simpson, Kerry E; Devine, Bryan C; Woolley, Richard; Corcoran, Brendan M; French, Anne T

2008-01-01

The identification and assessment of myocardial failure in canine idiopathic dilated cardiomyopathy (DCM) is achieved using a variety of two-dimensional and Doppler echocardiographic techniques. More recently, the availability of tissue Doppler imaging (TDI) has raised the potential for development of new ways of more accurately identifying a disease phenotype. Nevertheless, TDI has not been universally adapted to veterinary clinical cardiology primarily because of the lack of information on its utility in diagnosis. We assessed the application of timing of left heart base descent using TDI in the identification of differences between DCM and normal dogs. The times from the onset of the QRS complex on a simultaneously recorded electrocardiograph to the onset (Q--S'), peak (Q--peak S'), and end (Q--end S') of the systolic velocity peak were measured in the interventricular septum (IVS) and the left ventricular free wall. The duration of S' was also calculated. The Q--S' (FW), Q--end S' (FW), and duration S' (FW) were correlated with ejection fraction in the diseased group (P < 0.05). In addition, Q--S', Q--peak S', Q--end S', and the peak S' velocity were prolonged in the diseased dogs at both the free wall and in the IVS (P < 0.01). The duration of S' was unaffected by disease status. These findings provide insight into the electromechanical uncoupling that occurs in canine DCM and identifies new TDI parameters that can be added to the range of Doppler and echocardiographic parameters used for detecting myocardial failure in the dog.

Improved Modeling and Prediction of Surface Wave Amplitudes

DTIC Science & Technology

2017-05-31

structures and derived attenuation coefficients from the Eurasian Q inversion study. 15. SUBJECT TERMS nuclear explosion monitoring, surface waves, membrane...24 4.6 Inversion of Eurasian Attenuation Data for Q Structure ........................................ 31 4.6.1 Data used in the Q Inversion ...33 4.6.2 Q Inversion Results

Vibration-synchronized magnetic resonance imaging for the detection of myocardial elasticity changes.

PubMed

Elgeti, Thomas; Tzschätzsch, Heiko; Hirsch, Sebastian; Krefting, Dagmar; Klatt, Dieter; Niendorf, Thoralf; Braun, Jürgen; Sack, Ingolf

2012-04-01

Vibration synchronized magnetic resonance imaging of harmonically oscillating tissue interfaces is proposed for cardiac magnetic resonance elastography. The new approach exploits cardiac triggered cine imaging synchronized with extrinsic harmonic stimulation (f = 22.83 Hz) to display oscillatory tissue deformations in magnitude images. Oscillations are analyzed by intensity threshold-based image processing to track wave amplitude variations over the cardiac cycle. In agreement to literature data, results in 10 volunteers showed that endocardial wave amplitudes during systole (0.13 ± 0.07 mm) were significantly lower than during diastole (0.34 ± 0.14 mm, P < 0.001). Wave amplitudes were found to decrease 117 ± 40 ms before myocardial contraction and to increase 75 ± 31 ms before myocardial relaxation. Vibration synchronized magnetic resonance imaging improves the temporal resolution of magnetic resonance elastography as it overcomes the use of extra motion encoding gradients, is less sensitive to susceptibility artifacts, and does not suffer from dynamic range constraints frequently encountered in phase-based magnetic resonance elastography. Copyright © 2012 Wiley Periodicals, Inc.

Hippocampal ripples down-regulate synapses.

PubMed

Norimoto, Hiroaki; Makino, Kenichi; Gao, Mengxuan; Shikano, Yu; Okamoto, Kazuki; Ishikawa, Tomoe; Sasaki, Takuya; Hioki, Hiroyuki; Fujisawa, Shigeyoshi; Ikegaya, Yuji

2018-03-30

The specific effects of sleep on synaptic plasticity remain unclear. We report that mouse hippocampal sharp-wave ripple oscillations serve as intrinsic events that trigger long-lasting synaptic depression. Silencing of sharp-wave ripples during slow-wave states prevented the spontaneous down-regulation of net synaptic weights and impaired the learning of new memories. The synaptic down-regulation was dependent on the N -methyl-d-aspartate receptor and selective for a specific input pathway. Thus, our findings are consistent with the role of slow-wave states in refining memory engrams by reducing recent memory-irrelevant neuronal activity and suggest a previously unrecognized function for sharp-wave ripples. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Wave-induced stress and breaking of sea ice in a coupled hydrodynamic discrete-element wave-ice model

NASA Astrophysics Data System (ADS)

Herman, Agnieszka

2017-11-01

In this paper, a coupled sea ice-wave model is developed and used to analyze wave-induced stress and breaking in sea ice for a range of wave and ice conditions. The sea ice module is a discrete-element bonded-particle model, in which ice is represented as cuboid grains floating on the water surface that can be connected to their neighbors by elastic joints. The joints may break if instantaneous stresses acting on them exceed their strength. The wave module is based on an open-source version of the Non-Hydrostatic WAVE model (NHWAVE). The two modules are coupled with proper boundary conditions for pressure and velocity, exchanged at every wave model time step. In the present version, the model operates in two dimensions (one vertical and one horizontal) and is suitable for simulating compact ice in which heave and pitch motion dominates over surge. In a series of simulations with varying sea ice properties and incoming wavelength it is shown that wave-induced stress reaches maximum values at a certain distance from the ice edge. The value of maximum stress depends on both ice properties and characteristics of incoming waves, but, crucially for ice breaking, the location at which the maximum occurs does not change with the incoming wavelength. Consequently, both regular and random (Jonswap spectrum) waves break the ice into floes with almost identical sizes. The width of the zone of broken ice depends on ice strength and wave attenuation rates in the ice.

Recent advances in the diagnosis and treatment of acute myocardial infarction

PubMed Central

Reddy, Koushik; Khaliq, Asma; Henning, Robert J

2015-01-01

The Third Universal Definition of Myocardial Infarction (MI) requires cardiac myocyte necrosis with an increase and/or a decrease in a patient’s plasma of cardiac troponin (cTn) with at least one cTn measurement greater than the 99th percentile of the upper normal reference limit during: (1) symptoms of myocardial ischemia; (2) new significant electrocardiogram (ECG) ST-segment/T-wave changes or left bundle branch block; (3) the development of pathological ECG Q waves; (4) new loss of viable myocardium or regional wall motion abnormality identified by an imaging procedure; or (5) identification of intracoronary thrombus by angiography or autopsy. Myocardial infarction, when diagnosed, is now classified into five types. Detection of a rise and a fall of troponin are essential to the diagnosis of acute MI. However, high sensitivity troponin assays can increase the sensitivity but decrease the specificity of MI diagnosis. The ECG remains a cornerstone in the diagnosis of MI and should be frequently repeated, especially if the initial ECG is not diagnostic of MI. There have been significant advances in adjunctive pharmacotherapy, procedural techniques and stent technology in the treatment of patients with MIs. The routine use of antiplatelet agents such as clopidogrel, prasugrel or ticagrelor, in addition to aspirin, reduces patient morbidity and mortality. Percutaneous coronary intervention (PCI) in a timely manner is the primary treatment of patients with acute ST segment elevation MI. Drug eluting coronary stents are safe and beneficial with primary coronary intervention. Treatment with direct thrombin inhibitors during PCI is non-inferior to unfractionated heparin and glycoprotein IIb/IIIa receptor antagonists and is associated with a significant reduction in bleeding. The intra-coronary use of a glycoprotein IIb/IIIa antagonist can reduce infarct size. Pre- and post-conditioning techniques can provide additional cardioprotection. However, the incidence and mortality due to MI continues to be high despite all these recent advances. The initial ten year experience with autologous human bone marrow mononuclear cells (BMCs) in patients with MI showed modest but significant increases in left ventricular (LV) ejection fraction, decreases in LV end-systolic volume and reductions in MI size. These studies established that the intramyocardial or intracoronary administration of stem cells is safe. However, many of these studies consisted of small numbers of patients who were not randomized to BMCs or placebo. The recent LateTime, Time, and Swiss Multicenter Trials in patients with MI did not demonstrate significant improvement in patient LV ejection fraction with BMCs in comparison with placebo. Possible explanations include the early use of PCI in these patients, heterogeneous BMC populations which died prematurely from patients with chronic ischemic disease, red blood cell contamination which decreases BMC renewal, and heparin which decreases BMC migration. In contrast, cardiac stem cells from the right atrial appendage and ventricular septum and apex in the SCIPIO and CADUCEUS Trials appear to reduce patient MI size and increase viable myocardium. Additional clinical studies with cardiac stem cells are in progress. PMID:26015857

Increase in electrocardiographic R-waves after revascularization in patients with acute myocardial infarction.

PubMed

Isobe, Satoshi; Takada, Yasuo; Ando, Akitada; Ohshima, Satoru; Yamada, Kiyoyasu; Nanasato, Mamoru; Unno, Kazumasa; Ogawa, Takuo; Kondo, Takahisa; Izawa, Hideo; Inden, Yasuya; Hirai, Makoto; Murohara, Toyoaki

2006-11-01

The physiological mechanism of the increase in the electrocardiographic (ECG) R-wave voltage after revascularization in patients with acute myocardial infarction (MI) needs to be elucidated. One hundred and thirty-eight MI patients (83: anterior MI, 45: inferior MI, 10: lateral MI) underwent ECG and echocardiography in both the acute and subacute phases after emergency revascularization, as well as a resting thallium-201/iodine-123 15-p-iodophenyl-3-(R,S)-methyl pentadecanoic acid myocardial scintigraphy in the acute phase. The total sum of the R-wave voltage (SigmaR) was calculated over multiple leads on ECG for each infarcted lesion. Scintigraphic defect on each tracer was expressed as the percentage (%) defect of the total left ventricular (LV) myocardium. The % defect-discordance on both images in the acute phase and the % increase in SigmaR and the absolute increase in LV ejection fraction from the acute to the subacute phase (DeltaEF) were also calculated. The SigmaR in the subacute phase was significantly greater than that in the acute phase (p<0.0001). The % increase in SigmaR significantly correlated with the DeltaEF (r=0.57, p<0.0001). The % increase in SigmaR also correlated with the % defect-discordance (r=0.68, p<0.0001). The increase in the ECG R-wave voltage reflects not only the improvement in myocardial perfusion but also the presence of salvaged myocardium after revascularization in acute MI patients.

Damping of Quasi-stationary Waves Between Two Miscible Liquids

NASA Technical Reports Server (NTRS)

Duval, Walter M. B.

2002-01-01

Two viscous miscible liquids with an initially sharp interface oriented vertically inside a cavity become unstable against oscillatory external forcing due to Kelvin-Helmholtz instability. The instability causes growth of quasi-stationary (q-s) waves at the interface between the two liquids. We examine computationally the dynamics of a four-mode q-s wave, for a fixed energy input, when one of the components of the external forcing is suddenly ceased. The external forcing consists of a steady and oscillatory component as realizable in a microgravity environment. Results show that when there is a jump discontinuity in the oscillatory excitation that produced the four-mode q-s wave, the interface does not return to its equilibrium position, the structure of the q-s wave remains imbedded between the two fluids over a long time scale. The damping characteristics of the q-s wave from the time history of the velocity field show overdamped and critically damped response; there is no underdamped oscillation as the flow field approaches steady state. Viscous effects serve as a dissipative mechanism to effectively damp the system. The stability of the four-mode q-s wave is dependent on both a geometric length scale as well as the level of background steady acceleration.

ECG feature extraction and disease diagnosis.

PubMed

Bhyri, Channappa; Hamde, S T; Waghmare, L M

2011-01-01

An important factor to consider when using findings on electrocardiograms for clinical decision making is that the waveforms are influenced by normal physiological and technical factors as well as by pathophysiological factors. In this paper, we propose a method for the feature extraction and heart disease diagnosis using wavelet transform (WT) technique and LabVIEW (Laboratory Virtual Instrument Engineering workbench). LabVIEW signal processing tools are used to denoise the signal before applying the developed algorithm for feature extraction. First, we have developed an algorithm for R-peak detection using Haar wavelet. After 4th level decomposition of the ECG signal, the detailed coefficient is squared and the standard deviation of the squared detailed coefficient is used as the threshold for detection of R-peaks. Second, we have used daubechies (db6) wavelet for the low resolution signals. After cross checking the R-peak location in 4th level, low resolution signal of daubechies wavelet P waves and T waves are detected. Other features of diagnostic importance, mainly heart rate, R-wave width, Q-wave width, T-wave amplitude and duration, ST segment and frontal plane axis are also extracted and scoring pattern is applied for the purpose of heart disease diagnosis. In this study, detection of tachycardia, bradycardia, left ventricular hypertrophy, right ventricular hypertrophy and myocardial infarction have been considered. In this work, CSE ECG data base which contains 5000 samples recorded at a sampling frequency of 500 Hz and the ECG data base created by the S.G.G.S. Institute of Engineering and Technology, Nanded (Maharashtra) have been used.

Differences in symptoms, first medical contact and pre-hospital delay times between patients with ST- and non-ST-elevation myocardial infarction.

PubMed

Ängerud, Karin H; Sederholm Lawesson, Sofia; Isaksson, Rose-Marie; Thylén, Ingela; Swahn, Eva

2017-11-01

In ST-elevation myocardial infarction, time to reperfusion is crucial for the prognosis. Symptom presentation in myocardial infarction influences pre-hospital delay times but studies about differences in symptoms between patients with ST-elevation myocardial infarction and non-ST-elevation myocardial infarction are sparse and inconclusive. The aim was to compare symptoms, first medical contact and pre-hospital delay times in patients with ST-elevation myocardial infarction and non-ST-elevation myocardial infarction. This multicentre, observational study included 694 myocardial infarction patients from five hospitals. The patients filled in a questionnaire about their pre-hospital experiences within 24 h of hospital admittance. Chest pain was the most common symptom in ST-elevation myocardial infarction and non-ST-elevation myocardial infarction (88.7 vs 87.0%, p=0.56). Patients with cold sweat (odds ratio 3.61, 95% confidence interval 2.29-5.70), jaw pain (odds ratio 2.41, 95% confidence interval 1.04-5.58), and nausea (odds ratio 1.70, 95% confidence interval 1.01-2.87) were more likely to present with ST-elevation myocardial infarction, whereas the opposite was true for symptoms that come and go (odds ratio 0.58, 95% confidence interval 0.38-0.90) or anxiety (odds ratio 0.52, 95% confidence interval 0.29-0.92). Use of emergency medical services was higher among patients admitted with ST-elevation myocardial infarction. The pre-hospital delay time from symptom onset to first medical contact was significantly longer in non-ST-elevation myocardial infarction (2:05 h vs 1:10 h, p=0.001). Patients with ST-elevation myocardial infarction differed from those with non-ST-elevation myocardial infarction regarding symptom presentation, ambulance utilisation and pre-hospital delay times. This knowledge is important to be aware of for all healthcare personnel and the general public especially in order to recognise symptoms suggestive of ST-elevation myocardial infarction and when to decide if there is a need for an ambulance.

A generalized two-fluid picture of non-driven collisionless reconnection and its relation to whistler waves

NASA Astrophysics Data System (ADS)

Yoon, Young Dae

2017-10-01

A generalized, intuitive two-fluid picture of 2D non-driven collisionless magnetic reconnection is described using results from a full-3D numerical simulation. The relevant two-fluid equations simplify to the condition that the flux associated with canonical circulation Q =me ∇ ×ue +qe B is perfectly frozen into the electron fluid. Q is the curl of P =meue +qe A , which is the electron canonical momenrum. Since ∇ . Q = 0 , the Q flux tubes are incompressible and so have a fixed volume. Because they are perfectly frozen into the electron fluid, the Q flux tubes cannot reconnect. Following the behavior of these Q flux tubes provides an intuitive insight into 2D collisionless reconnection of B . In the reconnection geometry, a small perturbation to the central electron current sheet effectively brings a localized segment of a Q flux tube towards the X-point. This flux tube segment is convected downwards with the central electron current, effectively stretching the flux tube, decreasing its cross-section to maintain a fixed volume and so increasing the magnitude of Q . Also, because Q is the sum of the electron vorticity and the magnetic field, the two terms may change in such a way that one term becomes smaller while the other becomes larger while preserving constant Q flux. This allows magnetic reconnection, which is a conversion of magnetic field into particle velocity, to occur without any dissipation mechanism. The entire process has positive feedback with no restoring mechanism and therefore is an instability. The Q motion provides an interpretation for other phenomena as well, such as spiked central electron current filaments. The simulated reconnection rate was found to agree with a previous analytical calculation having the same geometry. Energy analysis shows that the magnetic energy is converted and propagated mainly in the form of the Poynting flux, while helicity analysis shows that the canonical helicity ∫ P . QdV as a whole must be considered when analyzing reconnection. A mechanism for whistler wave generation and propagation is also described, with comparisons to recent spacecraft observations. National Science Foundation under Award no. 1059519, Air Force Office of Scientific Research under Award No. FA9550-11-1-0184, U.S. Department of Energy Office of Science, Office of Fusion Energy Sciences under Award No. DE-FG02-04ER54755.

[Heart rupture in acute myocardial infarction: multicenter observational study of the coronary unit of Piedmont].

PubMed

Pron, Paolo Giay; Angelino, Paolo; Varbella, Ferdinando; Bongioanni, Sergio; Masi, Andrea Sibona; Iazzolino, Ernesto; Bonfiglio, Giovanna; Brusin, Maria Cristina Rosa; Mainardi, Loredana; Nicastro, Cristina; Bouslenko, Zoe; Conte, Maria Rosa

2002-02-01

The aim of this study was to prospectively evaluate the incidence of cardiac rupture during myocardial infarction (MI) as well as the predictive value of the main cardiac rupture risk factors. The study was carried out in 17 coronary care units (CCU) between January and December 1999 in the Piedmont region (Italy). The incidence of cardiac rupture was 1.4% of the total number of MI (n = 3041). Data from 13 out of 17 CCU showed the following causes of death during MI: 66% heart failure, 16% cardiac rupture, 7% arrhythmias, 11% others. Twenty-seven percent out of 44 cardiac ruptures had prior angina, 9% prior MI; 24% of patients were diabetic; 38% had anterior wall MI; 62% infero-postero-lateral MI; 86% showed ST-segment elevation, and 79.5% developed Q waves. Thrombolysis was administered in 39% of cases. Forty-three percent cardiac ruptures occurred within 24 hours. Electromechanical dissociation was present in 73% of cases, syncope and hypotension in 43%, bradycardia in 30%. An echocardiogram was performed in 89% of cases in the suspicion of cardiac rupture but only 45% showed severe pericardial effusion. One patient was referred to surgery but he died in the postoperative period. Autoptical diagnosis was made in 32% of cases. All patients died. The analysis of some qualitative variables (gender, thrombolysis, MI localization, ST-segment/non-ST-segment elevation) in 8 out of 17 CCU, between the cardiac rupture group (n = 22) and the MI group (n = 1330) showed a significant result only for the female gender. Cardiac rupture is the second cause of death during MI after heart failure; there is a higher incidence of cardiac rupture in infero-postero-lateral MI, after the first 24 hours particularly in the female gender; there is a low global incidence (1.4%).

Sustained high βN plasmas on EAST tokamak

NASA Astrophysics Data System (ADS)

Gao, Xiang; the EAST team

2018-05-01

Sustained high normalized beta (βN ∼ 1.9) plasmas with an ITER-like tungsten divertor have been achieved on EAST tokamak recently. The high power NBI heating system of 4.8 MW and the 4.6 GHz lower hybrid wave of 1 MW were developed and applied to produce edge and internal transport barriers in high βN discharges. The central flat q profile with q (ρ) ∼ 1 at ρ < 0.3 region and edge safety factor q95 = 4.7 is identified by the multi-channel far-infrared laser polarimeter and the EFIT code. The fraction of non-inductive current is about 40%. The relation between fishbone activity and ITB formation is observed and discussed.

The roles of mid-myocardial and epicardial cells in T-wave alternans development: a simulation study.

PubMed

Janusek, D; Svehlikova, J; Zelinka, J; Weigl, W; Zaczek, R; Opolski, G; Tysler, M; Maniewski, R

2018-05-08

The occurrence of T-wave alternans in electrocardiographic signals was recently linked to susceptibility to ventricular arrhythmias and sudden cardiac death. Thus, by detecting and comprehending the origins of T-wave alternans, it might be possible to prevent such events. Here, we simulated T-wave alternans in a computer-generated human heart model by modulating the action potential duration and amplitude during the first part of the repolarization phase. We hypothesized that changes in the intracardiac alternans patterns of action potential properties would differentially influence T-wave alternans measurements at the body surface. Specifically, changes were simulated globally in the whole left and right ventricles to simulate concordant T-wave alternans, and locally in selected regions to simulate discordant and regional discordant, hereinafter referred to as "regional", T-wave alternans. Body surface potential maps and 12-lead electrocardiographic signals were then computed. In depth discrimination, the influence of epicardial layers on T-wave alternans development was significantly higher than that of mid-myocardial cells. Meanwhile, spatial discrimination revealed that discordant and regional action potential property changes had a higher influence on T-wave alternans amplitude than concordant changes. Notably, varying T-wave alternans sources yielded distinct body surface potential map patterns for T-wave alternans amplitude, which can be used for location of regions within hearts exhibiting impaired repolarization. The highest ability for T-wave alternans detection was achieved in lead V1. Ultimately, we proposed new parameters Vector Magnitude Alternans and Vector Angle Alternans, with higher ability for T-wave alternans detection when using multi-lead electrocardiographic signals processing than for single leads. Finally, QT alternans was found to be associated with the process of T-wave alternans generation. The distributions of the body surface T-wave alternans amplitude have been shown to have unique patterns depending on the type of alternans (concordant, discordant or regional) and the location of the disturbance in the heart. The influence of epicardial cells on T-wave alternans development is significantly higher than that of mid-myocardial cells, among which the sub-endocardial layer exerted the highest influence. QT interval alternans is identified as a phenomenon that correlate with T-wave alternans.

Coenzyme Q(10) , endothelial function, and cardiovascular disease.

PubMed

Littarru, Gian Paolo; Tiano, Luca; Belardinelli, Romualdo; Watts, Gerald F

2011-01-01

Since the time a precise role of coenzyme Q(10) (CoQ(10) ) in myocardial bioenergetics was established, the involvement of CoQ in the pathophysiology of heart failure was hypothesized. This provided the rationale for numerous clinical trials of CoQ(10) as adjunctive treatment for heart failure. A mild hypotensive effect of CoQ was reported in the early years of clinical use of this compound. We review early human and animal studies on the vascular effects of CoQ. We then focus on endothelial dysfunction in type 2 diabetes and the possible impact on this condition of antioxidants and nutritional supplements, and in particular the therapeutic effects of CoQ. The effect of CoQ(10) on endothelial dysfunction in ischemic heart disease is also reviewed together with recent data highlighting that treatment with CoQ(10) increases extracellular SOD activity. Copyright © 2011 International Union of Biochemistry and Molecular Biology, Inc.

Tunneling study of cavity grade Nb : possible magnetic scattering at the surface.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prolier, T.; Zasadzinski, J. F.; Cooley, L.

Tunneling spectroscopy was performed on Nb pieces prepared by the same processes used to etch and clean superconducting radio frequency (SRF) cavities. Air exposed, electropolished Nb exhibited a surface superconducting gap {Delta} = 1.55 meV, which is characteristic of a clean, bulk Nb. However, the tunneling density of states (DOS) was significantly broadened. The Nb pieces, which were treated with the same mild baking used to improve the Q slope in SRF cavities, reveal a sharper DOS. Good fits to the DOS were obtained by using the Shiba theory, suggesting that magnetic scattering of quasiparticles is the origin of themore » gapless surface superconductivity and a heretofore unrecognized contributor to the Q-slope problem of Nb SRF cavities.« less

Effect of pretreatment with coenzyme Q10 on isoproterenol-induced cardiotoxicity and cardiac hypertrophy in rats.

PubMed

Ghule, Arvindkumar E; Kulkarni, Chetan P; Bodhankar, Subhash L; Pandit, Vijaya A

2009-12-01

Coenzyme Q10 (CoQ10) is a lipid-soluble, vitamin-like substance found in the hydrophobic interior of the phospholipid bilayer of most cellular membranes. It appears to be involved in the coordinated regulation between oxidative stress and antioxidant capacity of heart tissue when the heart is subjected to oxidative stress in various pathogenic conditions. The objective of the present study was to investigate the effect of pretreatment with CoQ10 (100 mg/kg) on isoproterenol (ISO)-induced cardiotoxicity and cardiac hypertrophy in rats. Albino male Wistar rats (250-300 g) were evenly divided by lottery method into 1 of the following 3 groups: the ISO group (olive oil 2 mL/kg orally for 18 days and ISO 1 mg/kg IP from days 9-18); the CoQ10 + ISO group (CoQ10 100 mg/kg orally for 18 days and ISO 1 mg/kg IP from days 9-18); and the control group (olive oil 2 mL/kg orally for 18 days and water IP from days 9-18). Twenty-four hours after the last dose of water or ISO, the rats were anesthetized and an ECG was recorded. Blood was withdrawn by retro-orbital puncture for estimation of serum creatine kinase-MB (CK-MB) isoenzyme levels, lactate dehydrogenase (LDH) levels, and aspartate aminotransferase activities. The animals were euthanized using an overdose of ether. The hearts of 6 animals from each group were used for estimation of superoxide dismutase (SOD) activity, reduced glutathione (GSH) concentration, lipid peroxidation (LPO), malondialdehyde (MDA), and total protein concentration. Histopathology of the 2 remaining hearts in each group was carried out by a blinded technician. A total of 24 rats (8 in each group) were used in this study; all rats survived to study end. Compared with the control group, the ISO-treated rats had a significant change in heart to body weight ratio (P < 0.001); significant changes in the endogenous antioxidants (ie, significantly higher myocardial MDA concentration [P < 0.001]; significantly lower myocardial GSH concentration [P < 0.001] and SOD activity [P < 0.01]); and significantly higher serum activities of marker enzymes (eg, CK-MB [P < 0.001] and LDH [P < 0.001]). Compared with the ISO group, the CoQ10 + ISO group had a significant change in heart to body weight ratio (P < 0.001); significant changes in the endogenous antioxidants (ie, significantly lower MDA concentration [P < 0.05]; significantly higher myocardial GSH concentration [P < 0.001] and SOD activity [P < 0.05]); and significantly lower serum activities of marker enzymes (eg, CK-MB [P < 0.05] and LDH [P < 0.01]). Pretreatment with CoQ10 (100 mg/kg) for 18 days was associated with moderate protection against ISO-induced cardiotoxicity and cardiac hypertrophy, and with lower myocardial injury by preserving endogenous antioxidants and reducing LPO in rat heart.

Whistler Waves With Electron Temperature Anisotropy And Non-Maxwellian Distribution Functions

NASA Astrophysics Data System (ADS)

Masood, W.

2017-12-01

Low frequency waves (˜ 100Hz), popularly known as Lion roars, are ubiquitously observed by satellites in terrestrial magnetosheath. By dint of both wave and electron data from the Cluster spacecraft and employing the linear kinetic theory for the electromagnetic waves, Masood et. al. (Ann. Geophysicae. 24, 1725-1735 (2006)) examined the conjecture made by Thorne and Tsurutani (Nature, 93, 384 (1981)) that whistler waves with electron temperature anisotropy are the progenitors of lion roars. It turned out that the study based upon the bi-Maxwellian distribution function did not come up with a satisfactory explanation of certain disagreements between theory and data. In this paper, we revisit the problem using the generalized (r, q) distribution to carry out the linear stability analysis. It is shown that good qualitative and quantitative agreements are found between theory and data using this distribution. Whistler waves with electron temperature anisotropy are also investigated with other non-Maxwellian distribution functions and general comparison is made in the end and differences in each case are highlighted. The possible applications in space plasmas are also pointed out.

Agreement in electrocardiogram interpretation in patients with septic shock.

PubMed

Mehta, Sangeeta; Granton, John; Lapinsky, Stephen E; Newton, Gary; Bandayrel, Kristofer; Little, Anjuli; Siau, Chuin; Cook, Deborah J; Ayers, Dieter; Singer, Joel; Lee, Terry C; Walley, Keith R; Storms, Michelle; Cooper, Jamie; Holmes, Cheryl L; Hebert, Paul; Gordon, Anthony C; Presneill, Jeff; Russell, James A

2011-09-01

The reliability of electrocardiogram interpretation to diagnose myocardial ischemia in critically ill patients is unclear. In adults with septic shock, we assessed intra- and inter-rater agreement of electrocardiogram interpretation, and the effect of knowledge of troponin values on these interpretations. Prospective substudy of a randomized trial of vasopressin vs. norepinephrine in septic shock. Nine Canadian intensive care units. Adults with septic shock requiring at least 5 μg/min of norepinephrine for 6 hrs. Twelve-lead electrocardiograms were recorded before study drug, and 6 hrs, 2 days, and 4 days after study drug initiation. Two physician readers, blinded to patient data and group, independently interpreted electrocardiograms on three occasions (first two readings were blinded to patient data; third reading was unblinded to troponin). To calibrate and refine definitions, both readers initially reviewed 25 trial electrocardiograms representing normal to abnormal. Cohen's Kappa and the φ statistic were used to analyze intra- and inter-rater agreement. One hundred twenty-one patients (62.2 ± 16.5 yrs, Acute Physiology and Chronic Health Evaluation II 28.6 ± 7.7) had 373 electrocardiograms. Blinded to troponin, readers 1 and 2 interpreted 46.4% and 30.0% of electrocardiograms as normal, and 15.3% and 12.3% as ischemic, respectively. Intrarater agreement was moderate for overall ischemia (κ 0.54 and 0.58), moderate/good for "normal" (κ 0.69 and 0.55), fair to good for specific signs of ischemia (ST elevation, T inversion, and Q waves, reader 1 κ 0.40 to 0.69; reader 2 κ 0.56 to 0.70); and good/very good for atrial arrhythmias (κ 0.84 and 0.79) and bundle branch block (κ 0.88 and 0.79). Inter-rater agreement was fair for ischemia (κ 0.29), moderate for ST elevation (κ 0.48), T inversion (κ 0.52), and Q waves (κ 0.44), good for bundle branch block (κ 0.78), and very good for atrial arrhythmias (κ 0.83). Inter-rater agreement for ischemia improved from fair to moderate (κ 0.52, p = .028) when unblinded to troponin. In patients with septic shock, inter-rater agreement of electrocardiogram interpretation for myocardial ischemia was fair, and improved with troponin knowledge.

Conformal field theory construction for non-Abelian hierarchy wave functions

NASA Astrophysics Data System (ADS)

Tournois, Yoran; Hermanns, Maria

2017-12-01

The fractional quantum Hall effect is the paradigmatic example of topologically ordered phases. One of its most fascinating aspects is the large variety of different topological orders that may be realized, in particular non-Abelian ones. Here we analyze a class of non-Abelian fractional quantum Hall model states which are generalizations of the Abelian Haldane-Halperin hierarchy. We derive their topological properties and show that the quasiparticles obey non-Abelian fusion rules of type su (q)k . For a subset of these states we are able to derive the conformal field theory description that makes the topological properties—in particular braiding—of the state manifest. The model states we study provide explicit wave functions for a large variety of interesting topological orders, which may be relevant for certain fractional quantum Hall states observed in the first excited Landau level.

Wave functions of the Q .Q interaction in terms of unitary 9-j coefficients

NASA Astrophysics Data System (ADS)

Zamick, Larry; Harper, Matthew

2015-03-01

We obtain wave functions for two protons and two neutrons in the g9 /2 shell expressed as column vectors with amplitudes D (Jp,Jn) . When we use a quadrupole-quadrupole interaction (Q .Q ) we get, in many cases, a very strong overlap with wave functions given by a single set of unitary 9-j coefficients—U 9 j =<(jj ) 2 j(jjJB|(jj ) Jp(jj ) Jn) I> . Here JB=9 for even I T =0 states. For both even and odd T =1 states we take JB equal to 8 whilst for odd I ,T =0 we take JB to be 7. We compare the Q .Q results with those of a more realistic interaction.

Assessment of mechanical ventricular synchrony in Doberman Pinschers with dilated cardiomyopathy.

PubMed

López-Alvarez, Jordi; Fonfara, Sonja; Pedro, Brigite; Stephenson, Hannah; Cripps, Peter J; Dukes-McEwan, Joanna

2011-09-01

Loss of temporal synchrony of myocardial contraction has been shown to reduce systolic function and be responsible for disease progression in people. The objective of this study is the assessment of inter- and intra ventricular synchrony in healthy Doberman Pinschers and those with dilated cardiomyopathy (DCM) by use of conventional Doppler and tissue velocity imaging. A total of 60 scans from 35 client-owned Doberman Pinschers presented for cardiac evaluation were analysed. Retrospective analysis of data. Using the European Society of Veterinary Cardiology DCM taskforce scoring system, Doberman Pinschers were classified into 4 groups: Control (Group 1; n=12), depressed systolic function other than DCM (Group 2; n=9), preclinical DCM (Group 3; n=8) and symptomatic DCM (Group 4; n=6). The time intervals between the beginning of the QRS complex and the peak velocity of pulmonic flow (Q-P) and the peak aortic flow (Q-Ao) were used to assess global synchrony between both ventricles. The time intervals between the beginning of the QRS complex and the peak myocardial systolic velocity (Q-peak S) and the onset of myocardial systolic velocity (Q-start S) were measured at the base of the right and left ventricular free wall (RVFW and LVFW) and interventricular septum (IVS), and used to determine segmental longitudinal inter- and intra ventricular synchrony. No significant loss of global or segmental longitudinal inter- or intra ventricular synchrony was identified between the groups. Impairment of longitudinal fibre synchrony does not appear to be significantly associated with clinical status of DCM in Doberman Pinschers, although it was identified in certain individuals. Copyright © 2011 Elsevier B.V. All rights reserved.

Assessment of stenosis severity: Correlation of angiography, T1-201 scintigraphy, and intracoronary pressure gradients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bateman, T.; Raymond, M.; Czer, L.

1984-01-01

To clarify the relationship between angiographic and hemodynamic stenosis severity and the appearance during stress-redistribution myocardial T1-201 scintigraphy (Ex-T1) of a visual (V) or quantitative (Q) perfusion defect (PD) or washout (WO) abnormality, 24 pts with CAD underwent intracoronary pressure gradient study at bypass surgery (CABG). All had pre-CABG Ex-T1 without interval deterioration. The mean diastolic pressure gradient (MDG) measured at reproducible hyperemic flow rates was determined for 34 stenoses (13 LAD, 7 LCX, 14 RCA) and compared with the results of Ex-T1 in subtended myocardial regions (LAD=anterior; LCX=posterolateral; RCA=inferior). Fourteen stenoses (50-99% diameter narrowing) were unassociated with VPD despitemore » maximal exercise: MDG was 9 +- 5mmHg, with MDG/mean aortic diastolic pressure (ADP) ratio of 0.12 +- 0.07. QPD and QWO analysis detected 8 of these. Thirteen stenoses (90-100% severity) led to reversible VPD: MDG was 36 +- 11 mm Hg, MDG/ADP ratio was 0.52 +- 0.17, and Q analysis was abnormal in 12/13. Seven stenoses (90-100% severity) subtended infarcted myocardium: MDG was 42 +- 21 mm Hg, MDG/ADP ratio was 0.52 +- 0.18, and V and Q analyses were abnormal in all. From this study, the authors derive the following conclusion: 1) Ex-T1 correlates better with hemodynamic severity of stenoses than does angiography; 2) V abnormalities identify stenoses of major angiographic and hemodynamic severity, while Q analysis detects some (57% in this study) stenoses of lesser severity; and 3) stenoses causing reversible Ex-T1 abnormalities present similar hemodynamic impediments to those causing myocardial infarcts.« less

High-frequency Rayleigh-wave method

USGS Publications Warehouse

Xia, J.; Miller, R.D.; Xu, Y.; Luo, Y.; Chen, C.; Liu, J.; Ivanov, J.; Zeng, C.

2009-01-01

High-frequency (???2 Hz) Rayleigh-wave data acquired with a multichannel recording system have been utilized to determine shear (S)-wave velocities in near-surface geophysics since the early 1980s. This overview article discusses the main research results of high-frequency surface-wave techniques achieved by research groups at the Kansas Geological Survey and China University of Geosciences in the last 15 years. The multichannel analysis of surface wave (MASW) method is a non-invasive acoustic approach to estimate near-surface S-wave velocity. The differences between MASW results and direct borehole measurements are approximately 15% or less and random. Studies show that simultaneous inversion with higher modes and the fundamental mode can increase model resolution and an investigation depth. The other important seismic property, quality factor (Q), can also be estimated with the MASW method by inverting attenuation coefficients of Rayleigh waves. An inverted model (S-wave velocity or Q) obtained using a damped least-squares method can be assessed by an optimal damping vector in a vicinity of the inverted model determined by an objective function, which is the trace of a weighted sum of model-resolution and model-covariance matrices. Current developments include modeling high-frequency Rayleigh-waves in near-surface media, which builds a foundation for shallow seismic or Rayleigh-wave inversion in the time-offset domain; imaging dispersive energy with high resolution in the frequency-velocity domain and possibly with data in an arbitrary acquisition geometry, which opens a door for 3D surface-wave techniques; and successfully separating surface-wave modes, which provides a valuable tool to perform S-wave velocity profiling with high-horizontal resolution. ?? China University of Geosciences (Wuhan) and Springer-Verlag GmbH 2009.

On the rogue waves propagation in non-Maxwellian complex space plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

El-Tantawy, S. A., E-mail: samireltantawy@yahoo.com; El-Awady, E. I., E-mail: eielawady@hotmail.com; Tribeche, M., E-mail: mouloudtribeche@yahoo.fr, E-mail: mtribeche@usthb.dz

2015-11-15

The implications of the non-Maxwellian electron distributions (nonthermal/or suprathermal/or nonextensive distributions) are examined on the dust-ion acoustic (DIA) rogue/freak waves in a dusty warm plasma. Using a reductive perturbation technique, the basic set of fluid equations is reduced to a nonlinear Schrödinger equation. The latter is used to study the nonlinear evolution of modulationally unstable DIA wavepackets and to describe the rogue waves (RWs) propagation. Rogue waves are large-amplitude short-lived wave groups, routinely observed in space plasmas. The possible region for the rogue waves to exist is defined precisely for typical parameters of space plasmas. It is shown that themore » RWs strengthen for decreasing plasma nonthermality and increasing superthermality. For nonextensive electrons, the RWs amplitude exhibits a bit more complex behavior, depending on the entropic index q. Moreover, our numerical results reveal that the RWs exist with all values of the ion-to-electron temperature ratio σ for nonthermal and superthermal distributions and there is no limitation for the freak waves to propagate in both two distributions in the present plasma system. But, for nonextensive electron distribution, the bright- and dark-type waves can propagate in this case, which means that there is a limitation for the existence of freak waves. Our systematic investigation should be useful in understanding the properties of DIA solitary waves that may occur in non-Maxwellian space plasmas.« less

Double-Q spin-density wave in iron arsenide superconductors

DOE PAGES

Allred, J. M.; Taddei, K. M.; Bugaris, D. E.; ...

2016-01-25

Elucidating the nature of the magnetic ground state of iron-based superconductors is of paramount importance in unveiling the mechanism behind their high temperature superconductivity. Until recently, it was thought that superconductivity emerges only from an orthorhombic antiferromagnetic stripe phase, which can in principle be described in terms of either localized or itinerant spins. However, we recently reported that tetragonal symmetry is restored inside the magnetically ordered state of certain hole-doped compounds, revealing the existence of a new magnetic phase at compositions close to the onset of superconductivity. Here, we present Mossbauer data that show that half of the iron sitesmore » in this tetragonal phase are non-magnetic, establishing conclusively the existence of a novel magnetic ground state with a non-uniform magnetization that is inconsistent with localized spins. Instead, this state is naturally explained as the interference between two commensurate spin density waves, a rare example of collinear double-Q magnetic order. Finally, our results demonstrate the itinerant character of the magnetism of the iron pnictides, and the primary role played by magnetic degrees of freedom in determining their phase diagram.« less

In-Stent Restenosis of Drug-Eluting Stents Compared With a Matched Group of Patients With De Novo Coronary Artery Stenosis.

PubMed

Buchanan, Kyle D; Torguson, Rebecca; Rogers, Toby; Xu, Linzhi; Gai, Jiaxiang; Ben-Dor, Itsik; Suddath, William O; Satler, Lowell F; Waksman, Ron

2018-03-13

Drug-eluting stents (DES) significantly reduced the incidence of in-stent restenosis (ISR). However, ISR still exists in the contemporary DES era. Previously deemed to be a benign process, ISR leads to complex presentation and intervention. This study aimed to compare the presentation and outcome of DES-ISR versus de novo lesions. We performed a retrospective analysis of 11,666 patients receiving percutaneous coronary intervention from 2003 to 2017 and divided them into 2 groups by de novo stenosis and ISR. They were matched based on common cardiovascular risk factors at a 4:1 ratio, respectively. After matching, a total of 1,888 patients with 3,126 de novo lesions and 472 patients with 508 ISR lesions were analyzed. Patients with ISR presented more often with unstable angina (61% vs 45%, p <0.001) and less often with myocardial infarction (6% vs 14%, p <0.001). One-year composite major adverse cardiovascular event, defined as death, Q-wave myocardial infarction, and target vessel revascularization, was 10% in the de novo group and 17% in the ISR group (hazard ratio 1.98, 95% confidential interval 1.58 to 2.46, p <0.001). After adjusting for myocardial infarction presentation, hazard ratio of major adverse cardiovascular events was still higher for the ISR group at 1 year (2.03, 95% confidential interval 1.62 to 2.55, p <0.001). ISR of DES remains a therapeutic challenge and leads to complex presentation and worse outcomes compared with matched de novo patients. These data show that DES-ISR demands better appreciation and prevention with more precise stent technique and should motivate the continued development of fully bioresorbable scaffolds. Copyright © 2018 Elsevier Inc. All rights reserved.

Experimental model of transthoracic, vascular-targeted, photodynamically induced myocardial infarction.

PubMed

Chrastina, Adrian; Pokreisz, Peter; Schnitzer, Jan E

2014-01-15

We describe a novel model of myocardial infarction (MI) in rats induced by percutaneous transthoracic low-energy laser-targeted photodynamic irradiation. The procedure does not require thoracotomy and represents a minimally invasive alternative to existing surgical models. Target cardiac area to be photodynamically irradiated was triangulated from the thoracic X-ray scans. The acute phase of MI was histopathologically characterized by the presence of extensive vascular occlusion, hemorrhage, loss of transversal striations, neutrophilic infiltration, and necrotic changes of cardiomyocytes. Consequently, damaged myocardium was replaced with fibrovascular and granulation tissue. The fibrotic scar in the infarcted area was detected by computer tomography imaging. Cardiac troponin I (cTnI), a specific marker of myocardial injury, was significantly elevated at 6 h (41 ± 6 ng/ml, n = 4, P < 0.05 vs. baseline) and returned to baseline after 72 h. Triphenyltetrazolium chloride staining revealed transmural anterolateral infarcts targeting 25 ± 3% of the left ventricle at day 1 with a decrease to 20 ± 3% at day 40 (n = 6 for each group, P < 0.01 vs. day 1). Electrocardiography (ECG) showed significant ST-segment elevation in the acute phase with subsequent development of a pathological Q wave and premature ventricular contractions in the chronic phase of MI. Vectorcardiogram analysis of spatiotemporal electrical signal transduction revealed changes in inscription direction, QRS loop morphology, and redistribution in quadrant areas. The photodynamically induced MI in n = 51 rats was associated with 12% total mortality. Histological findings, ECG abnormalities, and elevated cTnI levels confirmed the photosensitizer-dependent induction of MI after laser irradiation. This novel rodent model of MI might provide a platform to evaluate new diagnostic or therapeutic interventions.

Combined atorvastatin and coenzyme Q10 improve the left ventricular function in isoproterenol-induced heart failure in rat.

PubMed

Garjani, Alireza; Andalib, Sina; Biabani, Sajjad; Soraya, Hamid; Doustar, Yousef; Garjani, Afagh; Maleki-Dizaji, Nasrin

2011-09-01

The effect of atorvastatin on cardiac remodeling, function, and homodynamic parameters in isoproterenol-induced heart failure was evaluated in the present study. A subcutaneous injection of isoproterenol (5mg/kg/day) for 10 days was used for the induction of heart failure. Isoproterenol administration produced intensive myocardial necrosis and fibrosis with a significant decrease in the arterial pressure indices, heart rate, contractility (LVdP/dt(max)) and relaxation (LVdP/dt(min)), but an increase in the left ventricular end-diastolic pressure. Rats were randomly assigned to control, treatment with only atorvastatin, and treatment with atorvastatin plus coenzyme Q10. Histopathological analysis showed a marked attenuation of myocyte necrosis and interstitial fibrosis in all atorvastatin treated groups (P<0.001). A low dose of atorvastatin (5mg/kg/day) significantly improved the left ventricular systolic pressure, contractility and relaxation (P<0.01). On the contrary, a high dose of atorvastatin (20mg/kg/day) worsened the isoproterenol-induced left ventricular dysfunction by a further reduction of LVdP/dt(max) from +2780 ± 94 to +1588 ± 248 (mmHg/s; P<0.01) and LVdP/dt(min) from -2007 ± 190 to -2939 ± 291 (mmHg/s; P<0.05). Co-administration of coenzyme Q10 with atorvastatin reversed the hemodynamic depression and the left ventricular dysfunction to a high level (P<0.001). There was a lower level of LVEDPs in the atorvastatin+coenzyme Q10 treated groups (3 ± 1 and 4 ± 1.4 versus 8 ± 3.5 and 14 ± 3.6 mmHg, respectively), thereby suggesting improvement in the myocardial stiffness by the combined coenzyme Q10 and atorvastatin treatment. The atorvastatin therapy attenuated myocardial necrosis and fibrosis in isoproterenol-induced heart failure. However, a high dose of the drug considerably worsened the left ventricular dysfunction and hemodynamic depression, which was reversed by coenzyme Q10 co-administration. Copyright © 2011 Elsevier B.V. All rights reserved.

A micromachined thermally compensated thin film Lamb wave resonator for frequency control and sensing applications

NASA Astrophysics Data System (ADS)

Wingqvist, G.; Arapan, L.; Yantchev, V.; Katardjiev, I.

2009-03-01

Micromachined thin film plate acoustic wave resonators (FPARs) utilizing the lowest order symmetric Lamb wave (S0) propagating in highly textured 2 µm thick aluminium nitride (AlN) membranes have been successfully demonstrated (Yantchev and Katardjiev 2007 IEEE Trans. Ultrason. Ferroelectr. Freq. Control 54 87-95). The proposed devices have a SAW-based design and exhibit Q factors of up to 3000 at a frequency around 900 MHz as well as design flexibility with respect to the required motional resistance. However, a notable drawback of the proposed devices is the non-zero temperature coefficient of frequency (TCF) which lies in the range -20 ppm K-1 to -25 ppm K-1. Thus, despite the promising features demonstrated, further device optimization is required. In this work temperature compensation of thin AlN film Lamb wave resonators is studied and experimentally demonstrated. Temperature compensation while retaining at the same time the device electromechanical coupling is experimentally demonstrated. The zero TCF Lamb wave resonators are fabricated onto composite AlN/SiO2 membranes. Q factors of around 1400 have been measured at a frequency of around 755 MHz. Finally, the impact of technological issues on the device performance is discussed in view of improving the device performance.

Ramp and periodic dynamics across non-Ising critical points

NASA Astrophysics Data System (ADS)

Ghosh, Roopayan; Sen, Arnab; Sengupta, K.

2018-01-01

We study ramp and periodic dynamics of ultracold bosons in an one-dimensional (1D) optical lattice which supports quantum critical points separating a uniform and a Z3 or Z4 symmetry broken density-wave ground state. Our protocol involves both linear and periodic drives which takes the system from the uniform state to the quantum critical point (for linear drive protocol) or to the ordered state and back (for periodic drive protocols) via controlled variation of a parameter of the system Hamiltonian. We provide exact numerical computation, for finite-size boson chains with L ≤24 using exact diagonalization (ED), of the excitation density D , the wave function overlap F , and the excess energy Q at the end of the drive protocol. For the linear ramp protocol, we identify the range of ramp speeds for which D and Q show Kibble-Zurek scaling. We find, based on numerical analysis with L ≤24 , that such scaling is consistent with that expected from critical exponents of the q -state Potts universality class with q =3 ,4 . For the periodic protocol, we show that the model displays near-perfect dynamical freezing at specific frequencies; at these frequencies D ,Q →0 and |F |→1 . We provide a semi-analytic explanation of such freezing behavior and relate this phenomenon to a many-body version of Stuckelberg interference. We suggest experiments which can test our theory.

Bulk-wave ultrasonic propagation imagers

NASA Astrophysics Data System (ADS)

Abbas, Syed Haider; Lee, Jung-Ryul

2018-03-01

Laser-based ultrasound systems are described that utilize the ultrasonic bulk-wave sensing to detect the damages and flaws in the aerospace structures. These systems apply pulse-echo or through transmission methods to detect longitudinal through-the-thickness bulk-waves. These thermoelastic waves are generated using Q-switched laser and non-contact sensing is performed using a laser Doppler vibrometer (LDV). Laser-based raster scanning is performed by either twoaxis translation stage for linear-scanning or galvanometer-based laser mirror scanner for angular-scanning. In all ultrasonic propagation imagers, the ultrasonic data is captured and processed in real-time and the ultrasonic propagation can be visualized during scanning. The scanning speed can go up to 1.8 kHz for two-axis linear translation stage based B-UPIs and 10 kHz for galvanometer-based laser mirror scanners. In contrast with the other available ultrasound systems, these systems have the advantage of high-speed, non-contact, real-time, and non-destructive inspection. In this paper, the description of all bulk-wave ultrasonic imagers (B-UPIs) are presented and their advantages are discussed. Experiments are performed with these system on various structures to proof the integrity of their results. The C-scan results produced from non-dispersive, through-the-thickness, bulk-wave detection show good agreement in detection of structural variances and damage location in all inspected structures. These results show that bulk-wave UPIs can be used for in-situ NDE of engineering structures.

Structure of picosecond pulses of a Q-switched and mode-locked diode-pumped Nd:YAG laser

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donin, V I; Yakovin, D V; Gribanov, A V

2015-12-31

The pulse duration of a diode-pumped Nd:YAG laser, in which Q-switching with mode-locking (QML regime) is achieved using a spherical mirror and a travelling-wave acousto-optic modulator, is directly measured with a streak camera. It is found that the picosecond pulses can have a non-single-pulse structure, which is explained by excitation of several competing transverse modes in the Q-switching regime with a pulse repetition rate of 1 kHz. In the case of cw mode-locking (without Q-switching), a new (auto-QML) regime is observed, in which the pulse train repetition rate is determined by the frequency of the relaxation oscillations of the lasermore » field while the train contains single picosecond pulses. (control of laser radiation parameters)« less

The ABC model: a non-hydrostatic toy model for use in convective-scale data assimilation investigations

NASA Astrophysics Data System (ADS)

Petrie, Ruth Elizabeth; Bannister, Ross Noel; Priestley Cullen, Michael John

2017-12-01

In developing methods for convective-scale data assimilation (DA), it is necessary to consider the full range of motions governed by the compressible Navier-Stokes equations (including non-hydrostatic and ageostrophic flow). These equations describe motion on a wide range of timescales with non-linear coupling. For the purpose of developing new DA techniques that suit the convective-scale problem, it is helpful to use so-called toy models that are easy to run and contain the same types of motion as the full equation set. Such a model needs to permit hydrostatic and geostrophic balance at large scales but allow imbalance at small scales, and in particular, it needs to exhibit intermittent convection-like behaviour. Existing toy models are not always sufficient for investigating these issues. A simplified system of intermediate complexity derived from the Euler equations is presented, which supports dispersive gravity and acoustic modes. In this system, the separation of timescales can be greatly reduced by changing the physical parameters. Unlike in existing toy models, this allows the acoustic modes to be treated explicitly and hence inexpensively. In addition, the non-linear coupling induced by the equation of state is simplified. This means that the gravity and acoustic modes are less coupled than in conventional models. A vertical slice formulation is used which contains only dry dynamics. The model is shown to give physically reasonable results, and convective behaviour is generated by localised compressible effects. This model provides an affordable and flexible framework within which some of the complex issues of convective-scale DA can later be investigated. The model is called the ABC model after the three tunable parameters introduced: A (the pure gravity wave frequency), B (the modulation of the divergent term in the continuity equation), and C (defining the compressibility).

Electrical wave propagation in an anisotropic model of the left ventricle based on analytical description of cardiac architecture.

PubMed

Pravdin, Sergey F; Dierckx, Hans; Katsnelson, Leonid B; Solovyova, Olga; Markhasin, Vladimir S; Panfilov, Alexander V

2014-01-01

We develop a numerical approach based on our recent analytical model of fiber structure in the left ventricle of the human heart. A special curvilinear coordinate system is proposed to analytically include realistic ventricular shape and myofiber directions. With this anatomical model, electrophysiological simulations can be performed on a rectangular coordinate grid. We apply our method to study the effect of fiber rotation and electrical anisotropy of cardiac tissue (i.e., the ratio of the conductivity coefficients along and across the myocardial fibers) on wave propagation using the ten Tusscher-Panfilov (2006) ionic model for human ventricular cells. We show that fiber rotation increases the speed of cardiac activation and attenuates the effects of anisotropy. Our results show that the fiber rotation in the heart is an important factor underlying cardiac excitation. We also study scroll wave dynamics in our model and show the drift of a scroll wave filament whose velocity depends non-monotonically on the fiber rotation angle; the period of scroll wave rotation decreases with an increase of the fiber rotation angle; an increase in anisotropy may cause the breakup of a scroll wave, similar to the mother rotor mechanism of ventricular fibrillation.

Lateral acoustic wave resonator comprising a suspended membrane of low damping resonator material

DOEpatents

Olsson, Roy H.; El-Kady; , Ihab F.; Ziaei-Moayyed, Maryam; Branch; , Darren W.; Su; Mehmet F.,; Reinke; Charles M.,

2013-09-03

A very high-Q, low insertion loss resonator can be achieved by storing many overtone cycles of a lateral acoustic wave (i.e., Lamb wave) in a lithographically defined suspended membrane comprising a low damping resonator material, such as silicon carbide. The high-Q resonator can sets up a Fabry-Perot cavity in a low-damping resonator material using high-reflectivity acoustic end mirrors, which can comprise phononic crystals. The lateral overtone acoustic wave resonator can be electrically transduced by piezoelectric couplers. The resonator Q can be increased without increasing the impedance or insertion loss by storing many cycles or wavelengths in the high-Q resonator material, with much lower damping than the piezoelectric transducer material.

Shifting from Implicit to Explicit Knowledge: Different Roles of Early- and Late-Night Sleep

ERIC Educational Resources Information Center

Yordanova, Juliana; Kolev, Vasil; Verleger, Rolf; Bataghva, Zhamak; Born, Jan; Wagner, Ullrich

2008-01-01

Sleep has been shown to promote the generation of explicit knowledge as indicated by the gain of insight into previously unrecognized task regularities. Here, we explored whether this generation of explicit knowledge depends on pre-sleep implicit knowledge, and specified the differential roles of slow-wave sleep (SWS) vs. rapid eye movement (REM)…

Correlation of Electrocardiographic Changes with Cardiac Magnetic Resonance Findings in Patients with Hypertrophic Cardiomyopathy

PubMed Central

Paixão, Gabriela Miana de Mattos; Veronesi, Horácio Eduardo; da Silva, Halsted Alarcão Gomes Pereira; de Alencar Neto, José Nunes; Maldi, Carolina de Paulo; Aguiar Filho, Luciano de Figueiredo; Pinto, Ibrahim Masciarelli Francisco; de França, Francisco Faustino de Albuquerque Carneiro; Correia, Edileide de Barros

2018-01-01

Background Electrocardiogram is the initial test in the investigation of heart disease. Electrocardiographic changes in hypertrophic cardiomyopathy have no set pattern, and correlates poorly with echocardiographic findings. Cardiac magnetic resonance imaging has been gaining momentum for better assessment of hypertrophy, as well as the detection of myocardial fibrosis. Objectives To correlate the electrocardiographic changes with the location of hypertrophy in hypertrophic cardiomyopathy by cardiac magnetic resonance. Methods This descriptive cross-sectional study evaluated 68 patients with confirmed diagnosis of hypertrophic cardiomyopathy by cardiac magnetic resonance. The patients’ electrocardiogram was compared with the location of the greatest myocardial hypertrophy by cardiac magnetic resonance. Statistical significance level of 5% and 95% confidence interval were adopted. Results Of 68 patients, 69% had septal hypertrophy, 21% concentric and 10% apical hypertrophies. Concentric hypertrophy showed the greatest myocardial fibrosis mass (p < 0.001) and the greatest R wave size in D1 (p = 0.0280). The amplitudes of R waves in V5 and V6 (p = 0.0391, p = 0.0148) were higher in apical hypertrophy, with statistical significance. Apical hypertrophy was also associated with higher T wave negativity in D1, V5 and V6 (p < 0.001). Strain pattern was found in 100% of the patients with apical hypertrophy (p < 0.001). Conclusion The location of myocardial hypertrophy by cardiac magnetic resonance can be correlated with electrocardiographic changes, especially for apical hypertrophy. PMID:29538524

Dynamics of kinetic geodesic-acoustic modes and the radial electric field in tokamak neoclassical plasmas

NASA Astrophysics Data System (ADS)

Xu, X. Q.; Belli, E.; Bodi, K.; Candy, J.; Chang, C. S.; Cohen, R. H.; Colella, P.; Dimits, A. M.; Dorr, M. R.; Gao, Z.; Hittinger, J. A.; Ko, S.; Krasheninnikov, S.; McKee, G. R.; Nevins, W. M.; Rognlien, T. D.; Snyder, P. B.; Suh, J.; Umansky, M. V.

2009-06-01

We present edge gyrokinetic simulations of tokamak plasmas using the fully non-linear (full-f) continuum code TEMPEST. A non-linear Boltzmann model is used for the electrons. The electric field is obtained by solving the 2D gyrokinetic Poisson equation. We demonstrate the following. (1) High harmonic resonances (n > 2) significantly enhance geodesic-acoustic mode (GAM) damping at high q (tokamak safety factor), and are necessary to explain the damping observed in our TEMPEST q-scans and consistent with the experimental measurements of the scaling of the GAM amplitude with edge q95 in the absence of obvious evidence that there is a strong q-dependence of the turbulent drive and damping of the GAM. (2) The kinetic GAM exists in the edge for steep density and temperature gradients in the form of outgoing waves, its radial scale is set by the ion temperature profile, and ion temperature inhomogeneity is necessary for GAM radial propagation. (3) The development of the neoclassical electric field evolves through different phases of relaxation, including GAMs, their radial propagation and their long-time collisional decay. (4) Natural consequences of orbits in the pedestal and scrape-off layer region in divertor geometry are substantial non-Maxwellian ion distributions and parallel flow characteristics qualitatively like those observed in experiments.

Measurement of viscoelastic properties of in vivo swine myocardium using Lamb Wave Dispersion Ultrasound Vibrometry (LDUV)

PubMed Central

Urban, Matthew W.; Pislaru, Cristina; Nenadic, Ivan Z.; Kinnick, Randall R.; Greenleaf, James F.

2012-01-01

Viscoelastic properties of the myocardium are important for normal cardiac function and may be altered by disease. Thus, quantification of these properties may aid with evaluation of the health of the heart. Lamb Wave Dispersion Ultrasound Vibrometry (LDUV) is a shear wave-based method that uses wave velocity dispersion to measure the underlying viscoelastic material properties of soft tissue with plate-like geometries. We tested this method in eight pigs in an open-chest preparation. A mechanical actuator was used to create harmonic, propagating mechanical waves in the myocardial wall. The motion was tracked using a high frame rate acquisition sequence, typically 2500 Hz. The velocities of wave propagation were measured over the 50–400 Hz frequency range in 50 Hz increments. Data were acquired over several cardiac cycles. Dispersion curves were fit with a viscoelastic, anti-symmetric Lamb wave model to obtain estimates of the shear elasticity, μ1, and viscosity, μ2 as defined by the Kelvin-Voigt rheological model. The sensitivity of the Lamb wave model was also studied using simulated data. We demonstrated that wave velocity measurements and Lamb wave theory allow one to estimate the variation of viscoelastic moduli of the myocardial walls in vivo throughout the course of the cardiac cycle. PMID:23060325

Calculating qP-wave traveltimes in 2-D TTI media by high-order fast sweeping methods with a numerical quartic equation solver

NASA Astrophysics Data System (ADS)

Han, Song; Zhang, Wei; Zhang, Jie

2017-09-01

A fast sweeping method (FSM) determines the first arrival traveltimes of seismic waves by sweeping the velocity model in different directions meanwhile applying a local solver. It is an efficient way to numerically solve Hamilton-Jacobi equations for traveltime calculations. In this study, we develop an improved FSM to calculate the first arrival traveltimes of quasi-P (qP) waves in 2-D tilted transversely isotropic (TTI) media. A local solver utilizes the coupled slowness surface of qP and quasi-SV (qSV) waves to form a quartic equation, and solve it numerically to obtain possible traveltimes of qP-wave. The proposed quartic solver utilizes Fermat's principle to limit the range of the possible solution, then uses the bisection procedure to efficiently determine the real roots. With causality enforced during sweepings, our FSM converges fast in a few iterations, and the exact number depending on the complexity of the velocity model. To improve the accuracy, we employ high-order finite difference schemes and derive the second-order formulae. There is no weak anisotropy assumption, and no approximation is made to the complex slowness surface of qP-wave. In comparison to the traveltimes calculated by a horizontal slowness shooting method, the validity and accuracy of our FSM is demonstrated.

Frequency-constant Q, unity and disorder

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hargreaves, N.D.

1995-12-31

In exploration geophysics we obtain information about the earth by observing its response to different types of applied force. The response can cover the full range of possible Q values (where Q, the quality factor, is a measure of energy dissipation), from close to infinity in the case of deep crustal seismic to close to 0 in the case of many electromagnetic methods. When Q is frequency-constant, however, the various types of response have a common scaling behavior and can be described as being self-affine. The wave-equation then takes on a generalised form, changing from the standard wave-equation at Qmore » = {infinity} to the diffusion equation at Q = 0, via lossy, diffusive, propagation at intermediate Q values. Solutions of this wave-diffusion equation at any particular Q value can be converted to an equivalent set of results for any other Q value. In particular it is possible to convert from diffusive to wave propagation by a mapping from Q < {infinity} to Q = {infinity}. In the context of seismic sounding this is equivalent to applying inverse Q-filtering; in a more general context the mapping integrates different geophysical observations by referencing them to the common result at Q = {infinity}. The self-affinity of the observations for frequency-constant Q is an expression of scale invariance in the fundamental physical properties of the medium of propagation, this being the case whether the mechanism of diffusive propagation is scattering of intrinsic attenuation. Scale invariance, or fractal scaling, is a general property of disordered systems; the assumption of frequency-constant Q not only implies a unity between different geophysical observations, but also suggests that it is the disordered nature of the earth`s sub-surface that is the unifying factor.« less

Complete regression of myocardial involvement associated with lymphoma following chemotherapy.

PubMed

Vinicki, Juan Pablo; Cianciulli, Tomás F; Farace, Gustavo A; Saccheri, María C; Lax, Jorge A; Kazelian, Lucía R; Wachs, Adolfo

2013-09-26

Cardiac involvement as an initial presentation of malignant lymphoma is a rare occurrence. We describe the case of a 26 year old man who had initially been diagnosed with myocardial infiltration on an echocardiogram, presenting with a testicular mass and unilateral peripheral facial paralysis. On admission, electrocardiograms (ECG) revealed negative T-waves in all leads and ST-segment elevation in the inferior leads. On two-dimensional echocardiography, there was infiltration of the pericardium with mild effusion, infiltrative thickening of the aortic walls, both atria and the interatrial septum and a mildly depressed systolic function of both ventricles. An axillary biopsy was performed and reported as a T-cell lymphoblastic lymphoma (T-LBL). Following the diagnosis and staging, chemotherapy was started. Twenty-two days after finishing the first cycle of chemotherapy, the ECG showed regression of T-wave changes in all leads and normalization of the ST-segment elevation in the inferior leads. A follow-up Two-dimensional echocardiography confirmed regression of the myocardial infiltration. This case report illustrates a lymphoma presenting with testicular mass, unilateral peripheral facial paralysis and myocardial involvement, and demonstrates that regression of infiltration can be achieved by intensive chemotherapy treatment. To our knowledge, there are no reported cases of T-LBL presenting as a testicular mass and unilateral peripheral facial paralysis, with complete regression of myocardial involvement.

Quantum phase transition in strongly correlated systems

NASA Astrophysics Data System (ADS)

Jiang, Longhua

In this thesis, we investigated the strongly correlated phenomena in bilayer quantum Hall effect, inhomogeneous superconductivity and Boson Hubbard model. Bilayer quantum Hall system is studied in chapter 2. By using the Composite Boson (CB) theory developed by J. Ye, we derive the ground state, quasihole and a quasihole-pair wave functions from the CB theory and its dual action. We find that the ground state wave function is the product of two parts, one in the charge sector which is the well known Halperin's (111) wave function and the other in the spin sector which is non-trivial at any finite d due to the gapless mode. So the total groundstate wave function differs from the well known (111) wave function at any finite d. In addition to commonly known multiplicative factors, the quasihole and quasihole-pair wave functions also contain non-trivial normalization factors multiplying the correct ground state wave function. Then we continue to study the quantum phase transition from the excitonic superfluid (ESF) to a possible pseudo-spin density wave (PSDW) at some intermediate distances driven by the magneto-roton minimum collapsing at a finite wavevector. We analyze the properties of the PSDW and explicitly show that a square lattice is the favored lattice. We suggest that correlated hopping of vacancies in the active and passive layers in the PSDW state leads to very large and temperature-dependent drag, consistent with the experimental data. Comparisons with previous microscopic numerical calculations are made. Further experimental implications are given. In chapter 3, we investigate inhomogeneous superconductivity. Starting from the Ginzburg-Landau free energy describing the normal state to Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state transition, we evaluate the free energy of seven most common lattice structures: stripe, square, triangular, Simple Cubic (SC), Face centered Cubic (FCC), Body centered Cubic (BCC) and Quasicrystal (QC). We find that the stripe phase, which is the original LO state, is the most stable phase. This result may be relevant to the detection of the FFLO state in some heavy fermion compounds and the pairing lattice structure of fermions with unequal populations on the BCS side of the Feshbach resonance in ultra-cold atoms. In chapter 4, the Boson Hubbard model is studied by duality transformation. Interacting bosons at filling factor f = p/q hopping on a lattice can be mapped to interacting vortices hopping on the dual lattice subject to a fluctuating dual " magnetic field" whose average strength through a dual plaquette is equal to the boson density f = p/q. So the kinetic term of the vortices is the same as the Hofstadter problem of electrons moving in a lattice in the presence of f = p/q flux per plaquette. Motivated by this mapping, we study the Hofstadter bands of vortices hopping in the presence of magnetic flux f = p/q per plaquette on the 5 most common bipartite and frustrated lattices namely square, honeycomb, triangular, dice and kagome lattices. We count the total number of bands and determine the number of minima in the lowest band and their locations. We also numerically calculate the bandwidths of the lowest Hofstadter bands in these lattices, which directly measure the mobility of the dual vortices. The less mobile the dual vortices are, the more likely the bosons are in a superfluid state. We find that, except for the kagome lattice at odd q, they all satisfy the exponential decay law W = Ae-cq even at the smallest q. At given q, the bandwidth W decreases in the order: triangle, square and honeycomb lattice. This indicates that the domain of the superfluid state of the original bosons increases in the order of the corresponding direct lattices: honeycome, square and triangular. When q = 2, we find that the lowest Hofstadter band is completely flat for both kagome and dice lattices. There is a gap on the kagome lattice, but no gap on dice lattice. This indicates that the boson ground state at half filling with nearest neighbor hopping on kagome lattice is always a superfluid state. The superfluid state remains stable slightly away from half filling. Our results show that the behaviors of bosons at or near half filling on kagome lattice are quite distinct from those on square, honeycomb and triangular lattices studied previously.

Propagation of Electron Acoustic Soliton, Periodic and Shock Waves in Dissipative Plasma with a q-Nonextensive Electron Velocity Distribution

NASA Astrophysics Data System (ADS)

El-Hanbaly, A. M.; El-Shewy, E. K.; Elgarayhi, A.; Kassem, A. I.

2015-11-01

The nonlinear properties of small amplitude electron-acoustic (EA) solitary and shock waves in a homogeneous system of unmagnetized collisionless plasma with nonextensive distribution for hot electrons have been investigated. A reductive perturbation method used to obtain the Kadomstev-Petviashvili-Burgers equation. Bifurcation analysis has been discussed for non-dissipative system in the absence of Burgers term and reveals different classes of the traveling wave solutions. The obtained solutions are related to periodic and soliton waves and their behavior are shown graphically. In the presence of the Burgers term, the EXP-function method is used to solve the Kadomstev-Petviashvili-Burgers equation and the obtained solution is related to shock wave. The obtained results may be helpful in better conception of waves propagation in various space plasma environments as well as in inertial confinement fusion laboratory plasmas.

Association of lipoprotein lipase D9N polymorphism with myocardial infarction in type 2 diabetes: the genetics, outcomes, and lipids in type 2 diabetes (GOLD) study.

PubMed

Izar, Maria C; Helfenstein, Tatiana; Ihara, Silvia S; Relvas, Waldir G; Santos, Andreza O; Fischer, Simone C; Pinto, Leonor E; Lopes, Ieda E; Pomaro, Daniel R; Fonseca, Marilia I; Bodanese, Luis C; Moriguchi, Emilio H; Saraiva, Jose F; Introcaso, Luiz; Souza, Agnaldo D; Scartezini, Marileia; Torres, Kerginaldo P; Zagury, Leao; Jardim, Paulo C; Costa, Eduardo A; Tacito, Lucia H; Forti, Adriana; Magalhaes, Maria E; Chacra, Antonio R; Bertolami, Marcelo C; Loures-Vale, Andreia A; Barros, Marco A; Xavier, Hermes T; Lyra, Ruy; Argamanijan, Dikran; Guimaraes, Armenio; Novazzi, Jose P; Kasinski, Nelson; Afiune, Abrahao; Martinez, Tania L; Santos, Raul D; Nicolau, Jose C; Cesar, Luiz A; Povoa, Rui M; Carvalho, Antonio C; Han, Sang W; Fonseca, Francisco A

2009-05-01

The association of polymorphisms affecting lipid metabolism with the risk of myocardial infarction (MI) in type 2 diabetes mellitus was investigated. The Genetics, Outcomes and Lipids in type 2 Diabetes (GOLD) Study is a prospective, multicenter study, conducted on 990 patients presenting diabetes and MI (n=386), or diabetes without previous manifestation of stroke, peripheral or coronary arterial disease (n=604), recruited from 27 institutions in Brazil. APO A1 (A/G -75 and C/T +83) and APO C3 (C/G 3'UTR) non-coding sequences, CETP (Taq 1B), LPL (D9N), APO E (epsilon2, epsilon3, epsilon4,), PON-1 (Q192R), and two LCAT variants Arg(147)-->Trp and Tyr(171)-->Stop were tested by PCR-RFLP. There was a higher prevalence of LPL DN genotype (19% vs.12%, p=0.03) and a higher frequency of the N allele (11% vs. 7%) among subjects with MI when compared to controls, with an odds ratio of MI for carriers of 9N allele of 2.46 (95% CI=1.79-3.39, p<0.0001). This association was present in men and women, in non-smokers and in hypertensive patients. A logistic regression model including gender, duration of diabetes, systolic blood pressure, HDL-C, left ventricle hypertrophy and D9N polymorphism showed that the latter still remained significantly associated with MI (OR=1.50, 95% CI=1.02-2.25, p=0.049). These findings suggest that D9N polymorphism can be a useful risk marker for myocardial infarction and that further potential candidate genes should be screened for exploratory analysis and for future therapeutic intervention in diabetes.

Non-equilibrium fluctuations of a semi-flexible filament driven by active cross-linkers

NASA Astrophysics Data System (ADS)

Weber, I.; Appert-Rolland, C.; Schehr, G.; Santen, L.

2017-11-01

The cytoskeleton is an inhomogeneous network of semi-flexible filaments, which are involved in a wide variety of active biological processes. Although the cytoskeletal filaments can be very stiff and embedded in a dense and cross-linked network, it has been shown that, in cells, they typically exhibit significant bending on all length scales. In this work we propose a model of a semi-flexible filament deformed by different types of cross-linkers for which one can compute and investigate the bending spectrum. Our model allows to couple the evolution of the deformation of the semi-flexible polymer with the stochastic dynamics of linkers which exert transversal forces onto the filament. We observe a q-2 dependence of the bending spectrum for some biologically relevant parameters and in a certain range of wave numbers q, as observed in some experiments. However, generically, the spatially localized forcing and the non-thermal dynamics both introduce deviations from the thermal-like q-2 spectrum.

Phase transition and field effect topological quantum transistor made of monolayer MoS2

NASA Astrophysics Data System (ADS)

Simchi, H.; Simchi, M.; Fardmanesh, M.; Peeters, F. M.

2018-06-01

We study topological phase transitions and topological quantum field effect transistor in monolayer molybdenum disulfide (MoS2) using a two-band Hamiltonian model. Without considering the quadratic (q 2) diagonal term in the Hamiltonian, we show that the phase diagram includes quantum anomalous Hall effect, quantum spin Hall effect, and spin quantum anomalous Hall effect regions such that the topological Kirchhoff law is satisfied in the plane. By considering the q 2 diagonal term and including one valley, it is shown that MoS2 has a non-trivial topology, and the valley Chern number is non-zero for each spin. We show that the wave function is (is not) localized at the edges when the q 2 diagonal term is added (deleted) to (from) the spin-valley Dirac mass equation. We calculate the quantum conductance of zigzag MoS2 nanoribbons by using the nonequilibrium Green function method and show how this device works as a field effect topological quantum transistor.

Stress Perfusion Cardiac Magnetic Resonance Imaging Effectively Risk Stratifies Diabetic Patients With Suspected Myocardial Ischemia.

PubMed

Heydari, Bobak; Juan, Yu-Hsiang; Liu, Hui; Abbasi, Siddique; Shah, Ravi; Blankstein, Ron; Steigner, Michael; Jerosch-Herold, Michael; Kwong, Raymond Y

2016-04-01

Diabetics remain at high risk of cardiovascular disease and mortality despite advancements in medical therapy. Noninvasive cardiac risk profiling is often more difficult in diabetics owing to the prevalence of silent ischemia with unrecognized myocardial infarction, reduced exercise capacity, nondiagnostic electrocardiographic changes, and balanced ischemia from diffuse epicardial coronary atherosclerosis and microvascular dysfunction. A consecutive cohort of 173 patients with diabetes mellitus (mean age, 61.7±11.9 years; 37% women) with suspected myocardial ischemia underwent stress perfusion cardiac magnetic resonance imaging. Patients were evaluated for adverse cardiac events after cardiac magnetic resonance imaging with mean follow-up time of 2.9±2.5 years. Mean hemoglobin A1c for the population was 7.9±1.8%. Primary end point was a composite of cardiac death and nonfatal myocardial infarction. Diabetics with no inducible ischemia (n=94) experienced an annualized event rate of 1.4% compared with 8.2% (P=0.0003) in those with inducible ischemia (n=79). Diabetics without late gadolinium enhancement or inducible ischemia had a low annual cardiac event rate (0.5% per year). The presence of inducible ischemia was the strongest unadjusted predictor (hazard ratio, 4.86; P<0.01) for cardiac death and nonfatal myocardial infarction. This association remained robust in adjusted stepwise multivariable Cox regression analysis (hazard ratio, 4.28; P=0.02). In addition, categorical net reclassification index using 5-year risk cutoffs of 5% and 10% resulted in reclassification of 43.4% of the diabetic cohort with net reclassification index of 0.38 (95% confidence interval, 0.20-0.56; P<0.0001). Stress perfusion cardiac magnetic resonance imaging provided independent prognostic utility and effectively reclassified risk in patients with diabetes mellitus referred for ischemic assessment. Further evaluation is required to determine whether a noninvasive imaging strategy with cardiac magnetic resonance imaging can favorably affect downstream outcomes and improve cost-effectiveness of care in diabetics. © 2016 American Heart Association, Inc.

The effect of short-term coenzyme Q10 supplementation and pre-cooling strategy on cardiac damage markers in elite swimmers.

PubMed

Emami, Ali; Tofighi, Asghar; Asri-Rezaei, Siamak; Bazargani-Gilani, Behnaz

2018-02-01

Strenuous physical exercise and hyperthermia may paradoxically induce oxidative stress and adverse effects on myocardial function. The purpose of this study was to investigate the effect of 14-d coenzyme Q10 (CoQ10) supplementation and pre-cooling on serum creatine kinase-MB (CK-MB), cardiac Troponin I (cTnI), myoglobin (Mb), lactate dehydrogenase (LD), total antioxidant capacity (TAC), lipid peroxidation (LPO) and CoQ10 concentration in elite swimmers. In total, thirty-six healthy males (mean age 17 (sd 1) years) were randomly selected and divided into four groups of supplementation, supplementation with pre-cooling, pre-cooling and control. During an eighteen-session protocol in the morning and evening, subjects attended speed and endurance swimming training sessions for 5 km in each session. Blood sampling was done before (two stages) and after (two stages) administration of CoQ10 and pre-cooling. ANCOVA and repeated measurement tests with Bonferroni post hoc test were used for the statistical analysis of the data. There was no significant statistical difference among groups for the levels of CK-MB, cTnI, Mb, LD, TAC, LPO and CoQ10 at the presampling (stages 1 and 2) (P>0·05). However, pre-cooling and control groups show a significant increase in the levels of CK-MB, cTnI, Mb, LD and LPO compared with the supplementation and supplementation with pre-cooling groups in the post-sampling (stages 1 and 2) (P<0·05), except for the TAC and CoQ10. Consequently, CoQ10 supplementation prevents adverse changes of myocardial damage and oxidative stress during swimming competition phase. Meanwhile, the pre-cooling strategy individually has no desired effect on the levels of CK-MB, cTnI, Mb, LD, LPO, TAC and CoQ10.

A new shock wave assisted sandalwood oil extraction technique

NASA Astrophysics Data System (ADS)

Arunkumar, A. N.; Srinivasa, Y. B.; Ravikumar, G.; Shankaranarayana, K. H.; Rao, K. S.; Jagadeesh, G.

A new shock wave assisted oil extraction technique from sandalwood has been developed in the Shock Waves Lab, IISc, Bangalore. The fragrant oil extracted from sandalwood finds variety of applications in medicine and perfumery industries. In the present method sandal wood specimens (2.5mm diameter and 25mm in length)are subjected to shock wave loading (over pressure 15 bar)in a constant area shock tube, before extracting the sandal oil using non-destructive oil extraction technique. The results from the study indicates that both the rate of extraction as well as the quantity of oil obtained from sandal wood samples exposed to shock waves are higher (15-40 percent) compared to non-destructive oil extraction technique. The compressive squeezing of the interior oil pockets in the sandalwood specimen due to shock wave loading appears to be the main reason for enhancement in the oil extraction rate. This is confirmed by the presence of warty structures in the cross-section and micro-fissures in the radial direction of the wood samples exposed to shock waves in the scanning electron microscopic investigation. In addition the gas chromatographic studies do not show any change in the q uality of sandal oil extracted from samples exposed to shock waves.

Predictive role of P-wave axis abnormalities in secondary cardiovascular prevention.

PubMed

Lazzeroni, Davide; Bini, Matteo; Camaiora, Umberto; Castiglioni, Paolo; Moderato, Luca; Ugolotti, Pietro Tito; Brambilla, Lorenzo; Brambilla, Valerio; Coruzzi, Paolo

2017-12-01

Background Abnormal P-wave axis has been correlated with an increased risk of all-cause and cardiovascular mortality in a general population. We aimed to evaluate the prognostic role of abnormal P-wave axis in patients undergoing myocardial revascularisation or cardiac valve surgery. Methods We considered data of 810 patients with available P-wave axis measure from a prospective monocentric registry of patients undergoing cardiovascular rehabilitation. A total of 436 patients (54%) underwent myocardial revascularisation, 253 (31%) valve surgery, 71 (9%) combined valve and coronary artery bypass graft surgery and 50 (6%) cardiac surgery for other cardiovascular disease. Mean follow-up was 47 ± 27 months. Results Over the whole group, P-wave axis was 43.8° ± 27.5° and an abnormal P-wave axis was found in 94 patients (12%). The risk of overall (hazard ratio (HR) 2.5, 95% confidence interval (CI) 1.6-4.0, P < 0.001) and cardiovascular mortality (HR 2.9, 95% CI 1.5-5.8, P = 0.002) was significantly higher in patients with abnormal P-wave axis even after adjustment for age, other electrocardiographic variables (PR, QRS, QTc intervals), left ventricular ejection fraction and left atrial volume index. After dividing the population according to the type of disease, patients with abnormal P-wave axis and ischaemic heart disease had 3.9-fold higher risk of cardiovascular mortality (HR 3.9, 95% CI 1.3-12.1, P = 0.017), while a 2.2-fold higher risk of cardiovascular mortality (HR 3.6, 95% CI 1.3-10.1, P = 0.015) was found in those with cardiac valve disease. Conclusion An abnormal P-wave axis represents an independent predictor of both overall and cardiovascular mortality in patients undergoing myocardial revascularisation or cardiac valve surgery.

Non-ischemic diabetic cardiomyopathy may initially exhibit a transient subclinical phase of hyperdynamic myocardial performance.

PubMed

Hensel, Kai O

2016-09-01

Cardiovascular complications are the key cause for mortality in diabetes mellitus. Besides ischemia-related cardiac malfunction there is growing evidence for non-ischemic diabetes-associated heart failure in both type 1 and type 2 diabetes mellitus. The underlying pathophysiology of non-ischemic diabetic cardiomyopathy (NIDC) is poorly understood and data on myocardial mechanics in early stages of the disease are rare. However, several studies in both human and experimental animal settings have reported prima facie unexplained features indicating myocardial hyperdynamics early in the course of the disease. The new hypothesis is that - other than previously thought - NIDC may be non-linear and initially feature an asymptomatic subclinical phase of myocardial hypercontractility that precedes the long-term development of diabetes-associated cardiac dysfunction and ultimately heart failure. Diabetes-induced metabolic imbalances may lead to a paradoxic inotropic increase and inefficient myocardial mechanics that finally result in a gradual deterioration of myocardial performance. In conclusion, diabetic patients should be screened regularly and early in the course of the disease utilizing ultra-sensitive myocardial deformation imaging in order to identify patients at risk for diabetes-associated heart failure. Moreover, hyperdynamic myocardial deformation might help distinguish non-ischemic from ischemic diabetic cardiomyopathy. Further studies are needed to illuminate the underlying pathophysiological mechanisms, the exact spatiotemporal evolvement of diabetic cardiomyopathy and its long-term relation to clinical outcome parameters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Approximation solution of Schrodinger equation for Q-deformed Rosen-Morse using supersymmetry quantum mechanics (SUSY QM)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alemgadmi, Khaled I. K., E-mail: azozkied@yahoo.com; Suparmi; Cari

2015-09-30

The approximate analytical solution of Schrodinger equation for Q-Deformed Rosen-Morse potential was investigated using Supersymmetry Quantum Mechanics (SUSY QM) method. The approximate bound state energy is given in the closed form and the corresponding approximate wave function for arbitrary l-state given for ground state wave function. The first excited state obtained using upper operator and ground state wave function. The special case is given for the ground state in various number of q. The existence of Rosen-Morse potential reduce energy spectra of system. The larger value of q, the smaller energy spectra of system.

New Role for Interleukin-13 Receptor α1 in Myocardial Homeostasis and Heart Failure.

PubMed

Amit, Uri; Kain, David; Wagner, Allon; Sahu, Avinash; Nevo-Caspi, Yael; Gonen, Nir; Molotski, Natali; Konfino, Tal; Landa, Natalie; Naftali-Shani, Nili; Blum, Galia; Merquiol, Emmanuelle; Karo-Atar, Danielle; Kanfi, Yariv; Paret, Gidi; Munitz, Ariel; Cohen, Haim Y; Ruppin, Eytan; Hannenhalli, Sridhar; Leor, Jonathan

2017-05-20

The immune system plays a pivotal role in myocardial homeostasis and response to injury. Interleukins-4 and -13 are anti-inflammatory type-2 cytokines, signaling via the common interleukin-13 receptor α1 chain and the type-2 interleukin-4 receptor. The role of interleukin-13 receptor α1 in the heart is unknown. We analyzed myocardial samples from human donors (n=136) and patients with end-stage heart failure (n=177). We found that the interleukin-13 receptor α1 is present in the myocardium and, together with the complementary type-2 interleukin-4 receptor chain Il4ra , is significantly downregulated in the hearts of patients with heart failure. Next, we showed that Il13ra1 -deficient mice develop severe myocardial dysfunction and dyssynchrony compared to wild-type mice (left ventricular ejection fraction 29.7±9.9 versus 45.0±8.0; P =0.004, left ventricular end-diastolic diameter 4.2±0.2 versus 3.92±0.3; P =0.03). A bioinformatic analysis of mouse hearts indicated that interleukin-13 receptor α1 regulates critical pathways in the heart other than the immune system, such as extracellular matrix (normalized enrichment score=1.90; false discovery rate q=0.005) and glucose metabolism (normalized enrichment score=-2.36; false discovery rate q=0). Deficiency of Il13ra1 was associated with reduced collagen deposition under normal and pressure-overload conditions. The results of our studies in humans and mice indicate, for the first time, a role of interleukin-13 receptor α1 in myocardial homeostasis and heart failure and suggests a new therapeutic target to treat heart disease. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Elevated leukocyte count and adverse hospital events in patients with acute coronary syndromes: findings from the Global Registry of Acute Coronary Events (GRACE).

PubMed

Furman, Mark I; Gore, Joel M; Anderson, Fredrick A; Budaj, Andrzej; Goodman, Shaun G; Avezum, Avaro; López-Sendón, José; Klein, Werner; Mukherjee, Debabrata; Eagle, Kim A; Dabbous, Omar H; Goldberg, Robert J

2004-01-01

To examine the association between elevated leukocyte count and hospital mortality and heart failure in patients enrolled in the multinational, observational Global Registry of Acute Coronary Events (GRACE). Elevated leukocyte count is associated with adverse hospital outcomes in patients presenting with acute myocardial infarction (AMI). The association of this prognostic factor with hospital mortality and heart failure in patients with other acute coronary syndromes (ACS) is unclear. We examined the association between admission leukocyte count and hospital mortality and heart failure in 8269 patients presenting with an ACS. This association was examined separately in patients with ST-segment elevation AMI, non-ST-segment elevation AMI, and unstable angina. Leukocyte count was divided into 4 mutually exclusive groups (Q): Q1 <6000, Q2 = 6000-9999, Q3 = 10,000-11,999, Q4 >12,000. Multiple logistic regression analysis was performed to examine the association between elevated leukocyte count and hospital events while accounting for the simultaneous effect of several potentially confounding variables. Increasing leukocyte count was significantly associated with hospital death (adjusted odds ratio [OR] 2.8, 95% CI 2.1-3.6 for Q4 compared to Q2 [normal range]) and heart failure (OR 2.7, 95% CI 2.2-3.4) for patients presenting with ACS. This association was seen in patients with ST-segment elevation AMI (OR for hospital death 3.2, 95% CI 2.1-4.7; OR for heart failure 2.4, 95% CI 1.8-3.3), non-ST-segment elevation AMI (OR for hospital death 1.9, 95% CI 1.2-3.0; OR for heart failure 1.7, 95% CI 1.1-2.5), or unstable angina (OR for hospital death 2.8, 95% CI 1.4-5.5; OR for heart failure 2.0, 95% CI 0.9-4.4). In men and women of all ages with the spectrum of ACS, initial leukocyte count is an independent predictor of hospital death and the development of heart failure.

Features in the speckle correlations of light scattered from volume-disordered dielectric media

NASA Astrophysics Data System (ADS)

Malyshkin, V.; McGurn, A. R.; Maradudin, A. A.

1999-03-01

A diagrammatic perturbation theory approach, based on a scalar wave treatment, is used to study the scattering of light of frequency ω from a volume disordered dielectric medium. The dielectric medium is described by a position-dependent dielectric constant of the form ɛ(r-->)=ɛ(ω)+δɛ(r-->), where ɛ(ω) does not depend on r-->, and δɛ(r-->) is a zero-mean Gaussian random process defined by <δɛ(r-->)δɛ(r-->')>=σ2 exp(-\\|r-->-r-->'\\|2/a2), where the angle brackets denote an average over the ensemble of realizations of δɛ(r-->), a is the correlation length of the disorder, and σ is the root mean square deviation of the dielectric constant from its average value ɛ(ω). The speckle correlation function C(q-->,k-->\\|q-->',k-->')=<[I(q-->\\|k-->)-\\|k-->)>][I(q-->'\\|k-->')-'\\|k-->')]> where I(q-->\\|k-->) is proportional to the differential-scattering coefficient for the scattering of light of incident wave vector k--> into light of wave vector q--> is computed. In these calculations the contributions associated with both ladder and maximally crossed diagrams are summed in a Feynman diagram treatment of the speckle correlator, in the approximation that only s-wave-scattering terms are retained. Results are presented for the differential-scattering coefficient of light scattered from the disordered medium, which displays the phenomenon of enhanced backscattering, and for the correlator C in the approximation where C=C(1)+C(10)+C(1.5). The contribution C(1) is proportional to δ(q-->-k-->-q-->'+k-->') and describes the memory and time-reversed memory effects. C(10) is proportional to δ(q-->-k-->+q-->'-k-->'), while C(1.5) is unrestricted in its dependence on q-->,k-->,q-->',k-->'. The latter two contributions have recently been treated in the scattering of light from randomly rough surfaces, but have not been previously treated in the scattering of light by volume disordered media. A number of peaks associated with resonant processes are observed in C(1.5) considered as a function of the wave vectors of the incident and scattered light.

The NEUF-DIX space project - Non-EquilibriUm Fluctuations during DIffusion in compleX liquids.

PubMed

Baaske, Philipp; Bataller, Henri; Braibanti, Marco; Carpineti, Marina; Cerbino, Roberto; Croccolo, Fabrizio; Donev, Aleksandar; Köhler, Werner; Ortiz de Zárate, José M; Vailati, Alberto

2016-12-01

Diffusion and thermal diffusion processes in a liquid mixture are accompanied by long-range non-equilibrium fluctuations, whose amplitude is orders of magnitude larger than that of equilibrium fluctuations. The mean-square amplitude of the non-equilibrium fluctuations presents a scale-free power law behavior q -4 as a function of the wave vector q, but the divergence of the amplitude of the fluctuations at small wave vectors is prevented by the presence of gravity. In microgravity conditions the non-equilibrium fluctuations are fully developed and span all the available length scales up to the macroscopic size of the systems in the direction parallel to the applied gradient. Available theoretical models are based on linearized hydrodynamics and provide an adequate description of the statics and dynamics of the fluctuations in the presence of small temperature/concentration gradients and under stationary or quasi-stationary conditions. We describe a project aimed at the investigation of Non-EquilibriUm Fluctuations during DIffusion in compleX liquids (NEUF-DIX). The focus of the project is on the investigation in micro-gravity conditions of the non-equilibrium fluctuations in complex liquids, trying to tackle several challenging problems that emerged during the latest years, such as the theoretical predictions of Casimir-like forces induced by non-equilibrium fluctuations; the understanding of the non-equilibrium fluctuations in multi-component mixtures including a polymer, both in relation to the transport coefficients and to their behavior close to a glass transition; the understanding of the non-equilibrium fluctuations in concentrated colloidal suspensions, a problem closely related with the detection of Casimir forces; and the investigation of the development of fluctuations during transient diffusion. We envision to parallel these experiments with state-of-the-art multi-scale simulations.

Coda Wave Analysis in Central-Western North America Using Earthscope Transportable Array Data

NASA Astrophysics Data System (ADS)

Escudero, C. R.; Doser, D. I.

2011-12-01

We determined seismic wave attenuation in the western and central United States (e.g. Washington, Oregon, California, Idaho, Nevada, Montana, Wyoming, Colorado, New Mexico, North Dakota, South Dakota, Nebraska, Kansas, Oklahoma, and Texas) using coda waves. We selected approximately twenty moderate earthquakes (magnitude between 5.5 and 6.5) located along the Mexican subduction zone, Gulf of California, southern and northern California, and off the coast of Oregon for the analysis. These events were recorded by the EarthScope transportable array (TA) network from 2008 to 2011. In this study we implemented a method based on the assumption that coda waves are single backscattered waves from randomly distributed heterogeneities to calculate the coda Q. The frequencies studied lie between 1 and 15 Hz. The scattering attenuation is calculated for frequency bands centered at 1.5, 3, 5, 7.5, 10.5, and 13.5 Hz. In this work, we present coda Q resolution maps along with a correlation analysis between coda Q and seismicity, tectonic and geology setting. We observed higher attenuation (low coda Q values) in regions of sedimentary cover, and lower attenuation (high coda Q values) in hard rock regions. Using the 4-6 Hz frequency band, we found the best general correlation between coda Q and central-western North America bedrock geology.

Lower age at first myocardial infarction in female compared to male smokers.

PubMed

Bähler, Caroline; Gutzwiller, Felix; Erne, Paul; Radovanovic, Dragana

2012-10-01

Smoking is one of the most important risk factors for myocardial infarction. Smokers usually suffer their first myocardial infarction earlier in life compared to non-smokers. This age difference seems to be greater in women than in men. The aim of this study was to examine the age and sex differences in terms of smoking in patients with first myocardial infarction who were enrolled in the Swiss National Registry of myocardial infarction, AMIS Plus. Data of 15,711 patients admitted to an AMIS Plus hospital between 1999 and 2008 with a first myocardial infarction were analysed. Several multivariate regression, interaction and sensitivity analyses were conducted. The mean age at first myocardial infarction was 68.5 ± 12.2 years for non-smokers and 56.6 ± 11.7 years for smokers (P < 0.001). After stratification by sex the difference between non-smokers and smokers was 10.2 years in men and 13.1 years in women. Even after adjustment for risk factors (overweight, hypertension, dyslipidaemia, diabetes), comorbidities (peripheral vascular disease, cerebrovascular disease, chronic lung disease), regular cardiovascular medication intake before admission, Killip classification and ECG on admission, male smokers were 8.7 years younger than male non-smokers at first myocardial infarction. In women, the age difference between smokers and non-smokers was 10.8 years, giving a sex-specific difference of 2.1 years (P < 0.001). In the AMIS Plus cohort, smoking was associated with younger age at first myocardial infarction and this was much more pronounced in women. Public health campaigns should take into account the impact of smoking on premature first myocardial infarction, especially in women.

Cardiac and non-cardiac causes of T-wave inversion in the precordial leads in adult subjects: A Dutch case series and review of the literature

PubMed Central

Said, Salah AM; Bloo, Rene; de Nooijer, Ramon; Slootweg, Andries

2015-01-01

AIM: To describe the electrocardiographic (ECG) phenomena characterized by T-wave inversion in the precordial leads in adults and to highlight its differential diagnosis. METHODS: A retrospective chart review of 8 adult patients who were admitted with ECG T-wave inversion in the anterior chest leads with or without prolongation of corrected QT (QTc) interval. They had different clinical conditions. Each patient underwent appropriate clinical assessment including investigation for myocardial involvement. Single and multimodality non-invasive, semi-invasive and invasive diagnostic approach were used to ascertain the diagnosis. The diagnostic assessment included biochemical investigation, cardiac and abdominal ultrasound, cerebral and chest computed tomography, nuclear medicine and coronary angiography. RESULTS: Eight adult subjects (5 females) with a mean age of 66 years (range 51 to 82) are analyzed. The etiology of T-wave inversion in the precordial leads were diverse. On admission, all patients had normal blood pressure and the ECG showed sinus rhythm. Five patients showed marked prolongation of the QTc interval. The longest QTc interval (639 ms) was found in the patient with pheochromocytoma. Giant T-wave inversion (≥ 10 mm) was found in pheochromocytoma followed by electroconvulsive therapy and finally ischemic heart disease. The deepest T-wave was measured in lead V3 (5 ×). In 3 patients presented with mild T-wave inversion (patients 1, 5 and 4 mm), the QTc interval was not prolonged (432, 409 and 424 msec), respectively. CONCLUSION: T-wave inversion associated with or without QTc prolongation requires meticulous history taking, physical examination and tailored diagnostic modalities to reach rapid and correct diagnosis to establish appropriate therapeutic intervention. PMID:25717356

Electrocardiographic Impact of Myocardial Diffuse Fibrosis and Scar: MESA (Multi-Ethnic Study of Atherosclerosis)

PubMed Central

Inoue, Yuko Y.; Ambale-Venkatesh, Bharath; Mewton, Nathan; Volpe, Gustavo J.; Ohyama, Yoshiaki; Sharma, Ravi K.; Wu, Colin O.; Liu, Chia-Ying; Bluemke, David A.; Soliman, Elsayed Z.; Lima, João A. C.

2017-01-01

Purpose To examine the associations of myocardial diffuse fibrosis and scar with surface electrocardiographic (ECG) parameters in individuals free of prior coronary heart disease in four different ethnicities. Materials and Methods This prospective cross-sectional study was approved by the institutional review boards, and all participants gave informed consent. A total of 1669 participants in the Multi-Ethnic Study of Atherosclerosis, or MESA, who were free of prior myocardial infarction underwent both ECG and cardiac magnetic resonance imaging. In individuals without a late gadolinium enhancement–defined myocardial scar (n = 1131), T1 mapping was used to assess left ventricular (LV) interstitial diffuse fibrosis. The associations of LV diffuse fibrosis or myocardial scar with ECG parameters (QRS voltage, QRS duration, and corrected QT interval [QTc]) were evaluated by using multivariable regression analyses adjusted for demographic data, risk factors for scar, LV end-diastolic volume, and LV mass. Results The mean age of the 1669 participants was 67.4 years ± 8.7 (standard deviation); 49.8% were women. Lower postcontrast T1 time at 12 minutes was significantly associated with lower QRS Sokolow-Lyon voltage (β = 15.1 µV/10 msec, P = .004), lower QRS Cornell voltage (β = 9.2 µV/10 msec, P = .031), and shorter QRS duration (β = 0.16 msec/10 msec, P = .049). Greater extracellular volume (ECV) fraction was also significantly associated with lower QRS Sokolow-Lyon voltage (β = −35.2 µV/1% ECV increase, P < .001) and Cornell voltage (β = −23.7 µV/1% ECV increase, P < .001), independent of LV structural indexes. In contrast, the presence of LV scar (n = 106) was associated with longer QTc (β = 4.3 msec, P = .031). Conclusion In older adults without prior coronary heart disease, underlying greater LV diffuse fibrosis is associated with lower QRS voltage and shorter QRS duration at surface ECG, whereas clinically unrecognized myocardial scar is associated with a longer QT interval. © RSNA, 2016 Online supplemental material is available for this article. PMID:27740904

Determination of the Role of Oxygen in Suspected Acute Myocardial Infarction by Biomarkers

ClinicalTrials.gov

2017-12-08

Acute Myocardial Infarction (AMI); Acute Coronary Syndrome (ACS); ST Elevation (STEMI) Myocardial Infarction; Ischemic Reperfusion Injury; Non-ST Elevation (NSTEMI) Myocardial Infarction; Angina, Unstable

Myocardial Energetics and Heart Failure: a Review of Recent Therapeutic Trials.

PubMed

Bhatt, Kunal N; Butler, Javed

2018-06-01

Several novel therapeutics being tested in patients with heart failure are based on myocardial energetics. This review will provide a summary of the recent trials in this area, including therapeutic options targeting various aspects of cellular and mitochondrial metabolism. Agents that improve the energetic balance in myocardial cells have the potential to improve clinical heart failure status. The most promising therapies currently under investigation in this arena include (1) elamipretide, a cardiolipin stabilizer; (2) repletion of iron deficiency with intravenous ferrous carboxymaltose; (3) coenzyme Q10; and (4) the partial adenosine receptor antagonists capadenoson and neladenosone. Myocardial energetics-based therapeutics are groundbreaking in that they utilize novel mechanisms of action to improve heart failure symptoms, without causing the adverse neurohormonal side effects associated with current guideline-based therapies. The drugs appear likely to be added to the heart failure therapy armamentarium as adjuncts to current regimens in the near future.

Switching of the Spin-Density-Wave in CeCoIn5 probed by Thermal Conductivity

NASA Astrophysics Data System (ADS)

Kim, Duk Y.; Lin, Shi-Zeng; Weickert, Franziska; Bauer, Eric D.; Ronning, Filip; Thompson, Joe D.; Movshovich, Roman

Unconventional superconductor CeCoIn5 orders magnetically in a spin-density-wave (SDW) in the low-temperature and high-field corner of the superconducting phase. Recent neutron scattering experiment revealed that the single-domain SDW's ordering vector Q depends strongly on the direction of the magnetic field, switching sharply as the field is rotated through the anti-nodal direction. This switching may be manifestation of a pair-density-wave (PDW) p-wave order parameter, which develops in addition to the well-established d-wave order parameter due to the SDW formation. We have investigated the hypersensitivity of the magnetic domain with a thermal conductivity measurement. The heat current (J) was applied along the [110] direction such that the Q vector is either perpendicular or parallel to J, depending on the magnetic field direction. A discontinuous change of the thermal conductivity was observed when the magnetic field is rotated around the [100] direction within 0 . 2° . The thermal conductivity with the Q parallel to the heat current (J ∥Q) is approximately 15% lager than that with the Q perpendicular to the heat current (J ⊥Q). This result is consistent with additional gapping of the nodal quasiparticle by the p-wave PDW coupled to SDW. Work at Los Alamos was performed under the auspices of the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering.

Prognostic and Practical Validation of Current Definitions of Myocardial Infarction Associated With Percutaneous Coronary Intervention.

PubMed

Tricoci, Pierluigi; Newby, L Kristin; Clare, Robert M; Leonardi, Sergio; Gibson, C Michael; Giugliano, Robert P; Armstrong, Paul W; Van de Werf, Frans; Montalescot, Gilles; Moliterno, David J; Held, Claes; Aylward, Philip E; Wallentin, Lars; Harrington, Robert A; Braunwald, Eugene; Mahaffey, Kenneth W; White, Harvey D

2018-05-14

In 13,038 patients with non-ST-segment elevation acute coronary syndrome undergoing index percutaneous coronary intervention (PCI) in the EARLY ACS (Early Glycoprotein IIb/IIIa Inhibition in Non-ST-Segment Elevation Acute Coronary Syndrome) and TRACER (Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome) trials, the relationship between PCI-related myocardial infarction (MI) and 1-year mortality was assessed. The definition of PCI-related MI is controversial. The third universal definition of PCI-related MI requires cardiac troponin >5 times the 99th percentile of the normal reference limit from a stable or falling baseline and PCI-related clinical or angiographic complications. The definition from the Society for Cardiovascular Angiography and Interventions (SCAI) requires creatine kinase-MB elevation >10 times the upper limit of normal (or 5 times if new electrocardiographic Q waves are present). Implications of these definitions on prognosis, prevalence, and implementation are not established. In our cohort of patients undergoing PCI, PCI-related MIs were classified using the third universal type 4a MI definition and SCAI criteria. In the subgroup of patients included in the angiographic core laboratory (ACL) substudy of EARLY ACS (n = 1,401) local investigator- versus ACL-reported angiographic complications were compared. Altogether, 2.0% of patients met third universal definition of PCI-related MI criteria, and 1.2% met SCAI criteria. One-year mortality was 3.3% with the third universal definition (hazard ratio: 1.96; 95% confidence interval: 1.24 to 3.10) and 5.3% with SCAI criteria (hazard ratio: 2.79; 95% confidence interval: 1.69 to 4.58; p < 0.001). Agreement between ACL and local investigators in detecting angiographic complications during PCI was overall moderate (κ = 0.53). The third universal definition of MI and the SCAI definition were both associated with significant risk for mortality at 1 year. Suboptimal concordance was observed between ACL and local investigators in identifying patients with PCI complications detected on angiography. (Trial to Assess the Effects of Vorapaxar [SCH 530348; MK-5348] in Preventing Heart Attack and Stroke in Participants With Acute Coronary Syndrome [TRA·CER] [Study P04736]; NCT00527943; EARLY ACS: Early Glycoprotein IIb/IIIa Inhibition in Patients With Non-ST-Segment Elevation Acute Coronary Syndrome [Study P03684AM2]; NCT00089895). Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Hypertensive crisis-induced electrocardiographic changes: a case series

PubMed Central

2009-01-01

Introduction Myocardial injury is one of the most notorious complications of a hypertensive crisis. Key electrocardiograph signs used to detect cardiac injury such as ST segment changes and cardiac arrhythmias usually indicate acute ongoing end-organ damage. Lack of early signs to predict end-organ damage might lead to a delay in the initiation of therapy and selection of the incorrect therapeutic strategy. Case presentation We describe five cases of tall, hyper acute symmetrical T-waves alone or accompanied by other electrocardiograph abnormalities in five healthy participants: three women aged 52, 60 and 62-years and two men aged 49 and 66-years, during a tyramine-monoamine oxidase-inhibitor interaction, phase I clinical trial. T-wave changes appeared early during the course of the hypertensive crisis and were attributed to subendocardial ischemia. The changes were transient and reverted to baseline in parallel with a fall in blood pressure. Conclusion Recognition of tall symmetrical T-waves in early phases of hypertensive crisis heralds commencement of myocardial damage. This calls for prompt medical intervention to avoid an impending irreversible myocardial injury. It is our belief that these findings will add new insight into the management of hypertensive crisis and will open avenues of further investigation. PMID:19918270

Hypertensive crisis-induced electrocardiographic changes: a case series.

PubMed

Farha, Khalid Abou; van Vliet, André; van Marle, Sjoerd; Vrijlandt, Patrick; Westenbrink, Daan

2009-08-20

Myocardial injury is one of the most notorious complications of a hypertensive crisis. Key electrocardiograph signs used to detect cardiac injury such as ST segment changes and cardiac arrhythmias usually indicate acute ongoing end-organ damage. Lack of early signs to predict end-organ damage might lead to a delay in the initiation of therapy and selection of the incorrect therapeutic strategy. We describe five cases of tall, hyper acute symmetrical T-waves alone or accompanied by other electrocardiograph abnormalities in five healthy participants: three women aged 52, 60 and 62-years and two men aged 49 and 66-years, during a tyramine-monoamine oxidase-inhibitor interaction, phase I clinical trial. T-wave changes appeared early during the course of the hypertensive crisis and were attributed to subendocardial ischemia. The changes were transient and reverted to baseline in parallel with a fall in blood pressure. Recognition of tall symmetrical T-waves in early phases of hypertensive crisis heralds commencement of myocardial damage. This calls for prompt medical intervention to avoid an impending irreversible myocardial injury. It is our belief that these findings will add new insight into the management of hypertensive crisis and will open avenues of further investigation.

The EISCAT_3D Project in Norway: E3DN

NASA Astrophysics Data System (ADS)

La Hoz, C.; Oksavik, K.

2013-12-01

EISCAT_3D (E3D) is a project to build the next generation of incoherent scatter radars endowed with 3-dimensional scalar and vector capabilities that will replace the current EISCAT radars in Northern Scandinavia. One active (transmitting) site in Norway and four passive (receiving) sites in the Nordic countries will provide 3-D vector imaging capabilities by rapid scanning and multi-beam forming. The unprecedented flexibility of the solid-state transmitter with high duty-cycle, arbitrary wave-forming and polarisation and its pulsed power of 10 MW will provide unrivalled experimental capabilities to investigate the highly non-stationary and non-homogeneous state of the polar upper atmosphere. Aperture Synthesis Imaging Radar (ASIR) will to endow E3D with imaging capabilities in 3-dimensions that includes sub-beam resolution. Complemented by pulse compression, it will provide 3-dimensional images of certain types of incoherent scatter radar targets resolved to about 100 metres at 100 km range, depending on the signal-to-noise ratio. The Norwegian scientific programme is inspired by the pioneer polar scientist Kristian Birkeland (picture) and includes pressing questions on polar upper atmospheric research, among others: (Q1) How to proceed beyond the present simplistic, static, stationary and homogeneous analysis of upper atmospheric and ionospheric processes? (Q2) How does space weather affect ionospheric processes and how to support modelling and space weather services? (Q3) How to advance fundamental plasma physics by employing the ionosphere as a natural plasma physics laboratory? (Q4) How does the influx of extraterrestrial material interact with the upper atmosphere and where does the material originate from? (Q5) How does solar activity couple from geospace into the lower atmosphere and climate system, and does this energy change the wave forcing of geospace from below? Kristian Birkeland, Norwegian scientist and pioneer in polar and auroral research.

[The 18F-FDG myocardial metabolic imaging in twenty seven pilots with regular aerobic training].

PubMed

Fang, Ting-Zheng; Zhu, Jia-Rui; Chuan, Ling; Zhao, Wen-Rui; Xu, Gen-Xiang; Yang, Min-Fu; He, Zuo-Xiang

2009-02-01

To evaluate the characteristics of myocardial (18)F-FDG imaging in pilots with regular aerobic exercise training. Twenty seven healthy male pilots with regular aerobic exercise training were included in this study. The subjects were divided into fasting (n = 17) or non-fasting group (n = 10). Fluorine-18-labeled deoxyglucose and Tc-99m-sestamibi dual-nuclide myocardial imaging were obtained at rest and at target heart rate during bicycle ergometer test. The exercise and rest myocardial perfusion imaging were analyzed for myocardial ischemia presence. The myocardial metabolism imaging was analyzed with the visual semi-quantitative analyses model of seventeen segments. The secondary-extreme heart rate (195-age) was achieved in all subjects. There was no myocardial ischemia in all perfusion imaging. In the visual qualitative analyses, four myocardial metabolism imaging failed in the fasting group while one failed in the non-fasting group (P > 0.05). In the visual semi-quantitative analyses, myocardial metabolism imaging scores at rest or exercise in all segments were similar between two groups (P > 0.05). In the fasting group, the myocardial metabolism imaging scores during exercise were significantly higher than those at rest in 6 segments (P < 0.05). In the non-fasting group, the scores of 3 exercise myocardial metabolism imaging were significantly higher than those at rest (P < 0.05). Satisfactory high-quality myocardial metabolism imaging could be obtained at fasting and exercise situations in subjects with regular aerobic exercise.

Third International Kharkov Symposium "Physics and Engineering of Millimeter and Submillimeter Waves" MSMW󈨦 Symposium Proceedings, Volume 1,

DTIC Science & Technology

1998-09-01

potential of the surface wave electromagnetic field; ea is the unit of the polarization vectors : ex = ela. = e2x= (qx/\\q\\)\\/L\\q\\/(ei + e0), ely... polarization basis of the incident wave: EB°=eB^(/kr), (1) where e„ is the cyclic unit vector , n = ±1, k is the wave vector . The equation describing...rectangular grid. From the direction determined by wave vector k0, the plane electromagnetic wave of linear polarization incidents onto the array. It

Uric Acid Level Has a J-Shaped Association with Arterial Stiffness in Korean Postmenopausal Women.

PubMed

Lee, Hyungbin; Jung, Young-Hyo; Kwon, Yu-Jin; Park, Byoungjin

2017-11-01

Uric acid has been reported to function both as an oxidant or antioxidant depending on the context. A previous study in the Korean population reported a positive linear association between serum uric acid level and arterial stiffness in men, but little is known about how serum uric acid level is related to the risk of increased arterial stiffness in Korean postmenopausal women. We performed a cross-sectional study of 293 subjects who participated in a health examination program run by the health promotion center of Gangnam Severance Hospital between October 2007 and July 2010. High brachial-ankle pulse wave velocity was defined as a brachial-ankle pulse wave velocity of more than 1,450 cm/s. The odds ratios (ORs) for high brachial-ankle pulse wave velocity were calculated using multivariate logistic regression analysis across uric acid quartiles after adjusting for other indicators of cardiovascular risk. The 293 postmenopausal women were divided into quartiles according to uric acid level. The mean brachial-ankle pulse wave velocity values of each quartile were as follows: Q1, 1,474 cm/s; Q2, 1,375 cm/s; Q3, 1,422 cm/s; Q4, 1,528 cm/s. The second quartile was designated as the control group based on mean brachial-ankle pulse wave velocity value. Multivariate adjusted ORs (95% confidence intervals) for brachial-ankle pulse wave velocity across the uric acid quartiles were 2.642 (Q1, 1.095-6.3373), 1.00, 4.305 (Q3, 1.798-10.307), and 4.375 (Q4, 1.923-9.949), after adjusting for confounding variables. Serum uric acid level has a J-shaped association with arterial stiffness in Korean postmenopausal women.

Hippo pathway deficiency reverses systolic heart failure after infarction.

PubMed

Leach, John P; Heallen, Todd; Zhang, Min; Rahmani, Mahdis; Morikawa, Yuka; Hill, Matthew C; Segura, Ana; Willerson, James T; Martin, James F

2017-10-12

Mammalian organs vary widely in regenerative capacity. Poorly regenerative organs, such as the heart are particularly vulnerable to organ failure. Once established, heart failure commonly results in mortality. The Hippo pathway, a kinase cascade that prevents adult cardiomyocyte proliferation and regeneration, is upregulated in human heart failure. Here we show that deletion of the Hippo pathway component Salvador (Salv) in mouse hearts with established ischaemic heart failure after myocardial infarction induces a reparative genetic program with increased scar border vascularity, reduced fibrosis, and recovery of pumping function compared with controls. Using translating ribosomal affinity purification, we isolate cardiomyocyte-specific translating messenger RNA. Hippo-deficient cardiomyocytes have increased expression of proliferative genes and stress response genes, such as the mitochondrial quality control gene, Park2. Genetic studies indicate that Park2 is essential for heart repair, suggesting a requirement for mitochondrial quality control in regenerating myocardium. Gene therapy with a virus encoding Salv short hairpin RNA improves heart function when delivered at the time of infarct or after ischaemic heart failure following myocardial infarction was established. Our findings indicate that the failing heart has a previously unrecognized reparative capacity involving more than cardiomyocyte renewal.

Experimental Myocardial Infarction Upregulates Circulating Fibroblast Growth Factor‐23

PubMed Central

Andrukhova, Olena; Slavic, Svetlana; Odörfer, Kathrin I; Erben, Reinhold G

2015-01-01

ABSTRACT Myocardial infarction (MI) is a major cause of death worldwide. Epidemiological studies have linked vitamin D deficiency to MI incidence. Because fibroblast growth factor‐23 (FGF23) is a master regulator of vitamin D hormone production and has been shown to be associated with cardiac hypertrophy per se, we explored the hypothesis that FGF23 may be a previously unrecognized pathophysiological factor causally linked to progression of cardiac dysfunction post‐MI. Here, we show that circulating intact Fgf23 was profoundly elevated, whereas serum vitamin D hormone levels were suppressed, after induction of experimental MI in rat and mouse models, independent of changes in serum soluble Klotho or serum parathyroid hormone. Both skeletal and cardiac expression of Fgf23 was increased after MI. Although the molecular link between the cardiac lesion and circulating Fgf23 concentrations remains to be identified, our study has uncovered a novel heart–bone–kidney axis that may have important clinical implications and may inaugurate the new field of cardio‐osteology. © 2015 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research (ASBMR). PMID:25858796

The bhuQ Gene Encodes a Heme Oxygenase That Contributes to the Ability of Brucella abortus 2308 To Use Heme as an Iron Source and Is Regulated by Irr

PubMed Central

Ojeda, Jenifer F.; Martinson, David A.; Menscher, Evan A.

2012-01-01

The Brucella BhuQ protein is a homolog of the Bradyrhizobium japonicum heme oxygenases HmuD and HmuQ. To determine if this protein plays a role in the ability of Brucella abortus 2308 to use heme as an iron source, an isogenic bhuQ mutant was constructed and its phenotype evaluated. Although the Brucella abortus bhuQ mutant DCO1 did not exhibit a defect in its capacity to use heme as an iron source or evidence of increased heme toxicity in vitro, this mutant produced increased levels of siderophore in response to iron deprivation compared to 2308. Introduction of a bhuQ mutation into the B. abortus dhbC mutant BHB2 (which cannot produce siderophores) resulted in a severe growth defect in the dhbC bhuQ double mutant JFO1 during cultivation under iron-restricted conditions, which could be rescued by the addition of FeCl3, but not heme, to the growth medium. The bhuQ gene is cotranscribed with the gene encoding the iron-responsive regulator RirA, and both of these genes are repressed by the other major iron-responsive regulator in the alphaproteobacteria, Irr. The results of these studies suggest that B. abortus 2308 has at least one other heme oxygenase that works in concert with BhuQ to allow this strain to efficiently use heme as an iron source. The genetic organization of the rirA-bhuQ operon also provides the basis for the proposition that BhuQ may perform a previously unrecognized function by allowing the transcriptional regulator RirA to recognize heme as an iron source. PMID:22636783

In vivo quantification of amyloid burden in TTR-related cardiac amyloidosis

PubMed Central

Kollikowski, Alexander Marco; Kahles, Florian; Kintsler, Svetlana; Hamada, Sandra; Reith, Sebastian; Knüchel, Ruth; Röcken, Christoph; Mottaghy, Felix Manuel; Marx, Nikolaus; Burgmaier, Mathias

2017-01-01

Summary Cardiac transthyretin-related (ATTR) amyloidosis is a severe cardiomyopathy for which therapeutic approaches are currently under development. Because non-invasive imaging techniques such as cardiac magnetic resonance imaging and echocardiography are non-specific, the diagnosis of ATTR amyloidosis is still based on myocardial biopsy. Thus, diagnosis of ATTR amyloidosis is difficult in patients refusing myocardial biopsy. Furthermore, myocardial biopsy does not allow 3D-mapping and quantification of myocardial ATTR amyloid. In this report we describe a 99mTc-DPD-based molecular imaging technique for non-invasive single-step diagnosis, three-dimensional mapping and semiquantification of cardiac ATTR amyloidosis in a patient with suspected amyloid heart disease who initially rejected myocardial biopsy. This report underlines the clinical value of SPECT-based nuclear medicine imaging to enable non-invasive diagnosis of cardiac ATTR amyloidosis, particularly in patients rejecting biopsy. PMID:29259858

Complete regression of myocardial involvement associated with lymphoma following chemotherapy

PubMed Central

Vinicki, Juan Pablo; Cianciulli, Tomás F; Farace, Gustavo A; Saccheri, María C; Lax, Jorge A; Kazelian, Lucía R; Wachs, Adolfo

2013-01-01

Cardiac involvement as an initial presentation of malignant lymphoma is a rare occurrence. We describe the case of a 26 year old man who had initially been diagnosed with myocardial infiltration on an echocardiogram, presenting with a testicular mass and unilateral peripheral facial paralysis. On admission, electrocardiograms (ECG) revealed negative T-waves in all leads and ST-segment elevation in the inferior leads. On two-dimensional echocardiography, there was infiltration of the pericardium with mild effusion, infiltrative thickening of the aortic walls, both atria and the interatrial septum and a mildly depressed systolic function of both ventricles. An axillary biopsy was performed and reported as a T-cell lymphoblastic lymphoma (T-LBL). Following the diagnosis and staging, chemotherapy was started. Twenty-two days after finishing the first cycle of chemotherapy, the ECG showed regression of T-wave changes in all leads and normalization of the ST-segment elevation in the inferior leads. A follow-up Two-dimensional echocardiography confirmed regression of the myocardial infiltration. This case report illustrates a lymphoma presenting with testicular mass, unilateral peripheral facial paralysis and myocardial involvement, and demonstrates that regression of infiltration can be achieved by intensive chemotherapy treatment. To our knowledge, there are no reported cases of T-LBL presenting as a testicular mass and unilateral peripheral facial paralysis, with complete regression of myocardial involvement. PMID:24109501

Use of wave intensity analysis of carotid arteries in identifying and monitoring left ventricular systolic function dynamics in rabbits.

PubMed

Zhang, Hui; Zheng, Rongqin; Qian, Xiaoxian; Zhang, Chengxi; Hao, Baoshun; Huang, Zeping; Wu, Tao

2014-03-01

Wave intensity analysis (WIA) of the carotid artery was conducted to determine the changes that occur in left ventricular systolic function after administration of doxorubicin in rabbits. Each randomly selected rabbit was subject to routine ultrasound, WIA of the carotid artery, cardiac catheterization and pathologic examination every week and was followed for 16 wk. The first positive peak (WI1) of the carotid artery revealed that left ventricular systolic dysfunction occurred earlier than conventional indexes of heart function. WI1 was highly, positively correlated with the maximum rate of rise in left ventricular pressure in cardiac catheterization (r = 0.94, p < 0.01) and moderately negatively correlated with the apoptosis index of myocardial cells, an indicator of myocardial damage (r = -0.69, p < 0.01). Ultrasound WIA of the carotid artery sensitively reflects early myocardial damage and cardiac function, and the result is highly consistent with cardiac catheterization findings and the apoptosis index of myocardial cells. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Left-to-right shunt reduction with intra-aortic balloon pump in postmyocardial infarction ventricular septal defect.

PubMed

Testuz, Ariane; Roffi, Marco; Bonvini, Robert Francis

2013-03-01

This case aims to describe the hemodynamic effects of intra-aortic balloon pump (IABP) in patients with ventricular septal defect (VSD) complicating myocardial infarction (MI). A 79-year-old man with no previous cardiovascular history presented to the emergency department with subacute inferior myocardial infarction associated with mild signs of systemic hypoperfusion. A transthoracic echocardiography revealed a large akinesia of the left ventricular inferior wall with preserved global left ventricular ejection fraction, as well as a large VSD in the midinferior portion of the interventricular septum. Coronary angiography showed an occlusion of the mid portion of a dominant circumflex coronary artery. The invasive hemodynamic evaluation showed a sizable left-to-right shunt (Q(p)/Q(s) = 3.1). Activation of the IABP led to an immediate reduction of the shunt (Q(p)/Q(s) = 2.4 = 22% reduction), an increase in systemic cardiac output (from 2.1 L/min to 2.4 L/min = +12%) and a decrease in the systemic vascular resistances (from 2240 to 1920 dyne-sec/cm(5) = 15% reduction). In patients with post-MI VSD, placement of IABP leads to an immediate reduction in left-to-right shunt and as a consequence to an increase in systemic cardiac output, which may allow hemodynamic stabilization of the patient prior to surgical VSD closure. Copyright © 2012 Wiley Periodicals, Inc.

Seismic imaging of Q structures by a trans-dimensional coda-wave analysis

NASA Astrophysics Data System (ADS)

Takahashi, Tsutomu

2017-04-01

Wave scattering and intrinsic attenuation are important processes to describe incoherent and complex wave trains of high frequency seismic wave (>1Hz). The multiple lapse time window analysis (MLTWA) has been used to estimate scattering and intrinsic Q values by assuming constant Q in a study area (e.g., Hoshiba 1993). This study generalizes this MLTWA to estimate lateral variations of Q values under the Bayesian framework in dimension variable space. Study area is partitioned into small areas by means of the Voronoi tessellation. Scattering and intrinsic Q in each small area are constant. We define a misfit function for spatiotemporal variations of wave energy as with the original MLTWA, and maximize the posterior probability with changing not only Q values but the number and spatial layout of the Voronoi cells. This maximization is conducted by means of the reversible jump Markov chain Monte Carlo (rjMCMC) (Green 1995) since the number of unknown parameters (i.e., dimension of posterior probability) is variable. After a convergence to the maximum posterior, we estimate Q structures from the ensemble averages of MCMC samples around the maximum posterior probability. Synthetic tests showed stable reconstructions of input structures with reasonable error distributions. We applied this method for seismic waveform data recorded by ocean bottom seismograms at the outer-rise area off Tohoku, and estimated Q values at 4-8Hz, 8-16Hz and 16-32Hz. Intrinsic Q are nearly constant at all frequency bands, and scattering Q shows two distinct strong scattering regions at petit spot area and high seismicity area. These strong scattering are probably related to magma inclusions and fractured structure, respectively. Difference between these two areas becomes clear at high frequencies. It means that scale dependences of inhomogeneities or smaller scale inhomogeneity is important to discuss medium property and origins of structural variations. While the generalized MLTWA is based on a classical waveform modeling in constant Q medium, this method can be a fundamental basis for Q structure imaging in the crust.

Electrical Wave Propagation in an Anisotropic Model of the Left Ventricle Based on Analytical Description of Cardiac Architecture

PubMed Central

Pravdin, Sergey F.; Dierckx, Hans; Katsnelson, Leonid B.; Solovyova, Olga; Markhasin, Vladimir S.; Panfilov, Alexander V.

2014-01-01

We develop a numerical approach based on our recent analytical model of fiber structure in the left ventricle of the human heart. A special curvilinear coordinate system is proposed to analytically include realistic ventricular shape and myofiber directions. With this anatomical model, electrophysiological simulations can be performed on a rectangular coordinate grid. We apply our method to study the effect of fiber rotation and electrical anisotropy of cardiac tissue (i.e., the ratio of the conductivity coefficients along and across the myocardial fibers) on wave propagation using the ten Tusscher–Panfilov (2006) ionic model for human ventricular cells. We show that fiber rotation increases the speed of cardiac activation and attenuates the effects of anisotropy. Our results show that the fiber rotation in the heart is an important factor underlying cardiac excitation. We also study scroll wave dynamics in our model and show the drift of a scroll wave filament whose velocity depends non-monotonically on the fiber rotation angle; the period of scroll wave rotation decreases with an increase of the fiber rotation angle; an increase in anisotropy may cause the breakup of a scroll wave, similar to the mother rotor mechanism of ventricular fibrillation. PMID:24817308

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

A generalized, intuitive two-fluid picture of 2D non-driven collisionless magnetic reconnection is described using results from a full-3D numerical simulation. The relevant two-fluid equations simplify to the condition that the flux associated with canonical circulation Q=m e∇×u e+q eB is perfectly frozen into the electron fluid. In the reconnection geometry, flux tubes defined by Q are convected with the central electron current, effectively stretching the tubes and increasing the magnitude of Q exponentially. This, coupled with the fact that Q is a sum of two quantities, explains how the magnetic fields in the reconnection region reconnect and give rise tomore » strong electron acceleration. The Q motion provides an interpretation for other phenomena as well, such as spiked central electron current filaments. The simulated reconnection rate was found to agree with a previous analytical calculation having the same geometry. Energy analysis shows that the magnetic energy is converted and propagated mainly in the form of the Poynting flux, and helicity analysis shows that the canonical helicity ∫P·Q dV as a whole must be considered when analyzing reconnection. A mechanism for whistler wave generation and propagation is also described, with comparisons to recent spacecraft observations.« less

Droplet digital PCR as a novel detection method for quantifying microRNAs in acute myocardial infarction.

PubMed

Robinson, S; Follo, M; Haenel, D; Mauler, M; Stallmann, D; Tewari, M; Duerschmied, D; Peter, K; Bode, C; Ahrens, I; Hortmann, M

2018-04-15

micro-RNAs have shown promise as potential biomarkers for acute myocardial infarction and ischemia-reperfusion injury (I/R). Most recently droplet digital polymerase chain reaction (ddPCR) has been introduced as a more reliable and reproducible method for detecting micro-RNAs. We aimed to demonstrate the improved technical performance and diagnostic potential of ddPCR by measuring micro-RNAs in ST-elevation myocardial infarction (STEMI). A dilution series was performed in duplicate on synthetic Caenorrhabditis elegans-miR-39, comparing quantitative real-time PCR (qRT-PCR) and ddPCR. We used ddPCR and qRT-PCR to quantify the serum levels of miR-21, miR-208a and miR-499 between STEMI patients (n=24) and stable coronary artery disease (CAD) patients (n=20). In STEMI, I/R injury was assessed via measurement of ST-segment resolution. In the dilution series, ddPCR demonstrated superior coefficient of variation (12.1%vs.32.9%) and limit of detection (0.9325 vs.2.425copies/μl). In the patient cohort, ddPCR demonstrated greater differences in miR-21 levels (2190.5 vs. 484.7copies/μl; p=0.0004 for ddPCR and 136.4 vs. 122.8copies/μl; p=0.2273 for qRT-PCR) and in miR-208a (0 vs. 24.1copies/μl, p=0.0013 for ddPCR and 0 vs. 0copies/μl, p=0.0032 for qRT-PCR), with similar differences observed in miR-499 levels (9.4 vs. 81.5copies/μl, p<0.0001 for ddPCR and 0 vs. 19.41copies/μl, p<0.0001 for qRT-PCR). ddPCR also more accurately defined STEMI for all miRNAs (area under the curve (AUC) of 0.8021/0.7740/0.9063 for miR-21/208a/499 with ddPCR vs. AUC of 0.6083/0.6917/0.8417 with qRT-PCR). However, there was no association between miR-21/208a/499 levels and ischemia-reperfusion injury. ddPCR demonstrates superiority in both technical performance and diagnostic potential compared to qRT-PCR. Ultimately, this supports its use as a diagnostic method for quantifying micro-RNAs, particularly in large multi-center trials. Copyright © 2017 Elsevier B.V. All rights reserved.

Linking non-culturable (qPCR) and culturable enterococci densities with hydrometeorological conditions

USGS Publications Warehouse

Byappanahalli, Muruleedhara N.; Whitman, Richard L.; Shively, Dawn A.; Nevers, Meredith B.

2010-01-01

Quantitative polymerase chain reaction (qPCR) measurement of enterococci has been proposed as a rapid technique for assessment of beach water quality, but the response of qPCR results to environmental conditions has not been fully explored. Culture-based E. coli and enterococci have been used in empirical predictive models to characterize their responses to environmental conditions and to increase monitoring frequency and efficiency. This approach has been attempted with qPCR results only in few studies. During the summer of 2006, water samples were collected from two southern Lake Michigan beaches and the nearby river outfall (Burns Ditch) and were analyzed for enterococci by culture-based and non-culture-based (i.e., qPCR) methods, as well as culture-based E. coli. Culturable enterococci densities (log CFU/100 ml) for the beaches were significantly correlated with enterococci qPCR cell equivalents (CE) (R = 0.650, P N = 32). Enterococci CE and CFU densities were highest in Burns Ditch relative to the beach sites; however, only CFUs were significantly higher (P R = 0.565, P N = 32). Culturable E. coli and enterococci densities were significantly correlated (R = 0.682, P N = 32). Regression analyses suggested that enterococci CFU could be predicted by lake turbidity, Burns Ditch discharge, and wind direction (adjusted R2 = 0.608); enterococci CE was best predicted by Burns Ditch discharge and log-transformed lake turbidity × wave height (adjusted R2 = 0.40). In summary, our results show that analytically, the qPCR method compares well to the non-culture-based method for measuring enterococci densities in beach water and that both these approaches can be predicted by hydrometeorological conditions. Selected predictors and model results highlight the differences between the environmental responses of the two method endpoints and the potentially high variance in qPCR results

Alternative stable qP wave equations in TTI media with their applications for reverse time migration

NASA Astrophysics Data System (ADS)

Zhou, Yang; Wang, Huazhong; Liu, Wenqing

2015-10-01

Numerical instabilities may arise if the spatial variation of symmetry axis is handled improperly when implementing P-wave modeling and reverse time migration in heterogeneous tilted transversely isotropic (TTI) media, especially in the cases where fast changes exist in TTI symmetry axis’ directions. Based on the pseudo-acoustic approximation to anisotropic elastic wave equations in Cartesian coordinates, alternative second order qP (quasi-P) wave equations in TTI media are derived in this paper. Compared with conventional stable qP wave equations, the proposed equations written in stress components contain only spatial derivatives of wavefield variables (stress components) and are free from spatial derivatives involving media parameters. These lead to an easy and efficient implementation for stable P-wave modeling and imaging. Numerical experiments demonstrate the stability and computational efficiency of the presented equations in complex TTI media.

Seafloor character and sedimentary processes in eastern Long Island Sound and western Block Island Sound

USGS Publications Warehouse

Poppe, Lawrence J.; Cohen-DiGiacomo, M. L.; Smith, S.M.; Stewart, H.F.; Forfinski, N.A.

2006-01-01

Multibeam bathymetric data and seismic-reflection profiles collected in eastern Long Island Sound and western Block Island Sound reveal previously unrecognized glacial features and modern bedforms. Glacial features include an ice-sculptured bedrock surface, a newly identified recessional moraine, exposed glaciolacustrine sediments, and remnants of stagnant-ice-contact deposits. Modern bedforms include fields of transverse sand waves, barchanoid waves, giant scour depressions, and pockmarks. Bedform asymmetry and scour around obstructions indicate that net sediment transport is westward across the northern part of the study area near Fishers Island, and eastward across the southern part near Great Gull Island.

Sparsity-optimized separation of body waves and ground-roll by constructing dictionaries using tunable Q-factor wavelet transforms with different Q-factors

NASA Astrophysics Data System (ADS)

Chen, Xin; Chen, Wenchao; Wang, Xiaokai; Wang, Wei

2017-10-01

Low-frequency oscillatory ground-roll is regarded as one of the main regular interference waves, which obscures primary reflections in land seismic data. Suppressing the ground-roll can reasonably improve the signal-to-noise ratio of seismic data. Conventional suppression methods, such as high-pass and various f-k filtering, usually cause waveform distortions and loss of body wave information because of their simple cut-off operation. In this study, a sparsity-optimized separation of body waves and ground-roll, which is based on morphological component analysis theory, is realized by constructing dictionaries using tunable Q-factor wavelet transforms with different Q-factors. Our separation model is grounded on the fact that the input seismic data are composed of low-oscillatory body waves and high-oscillatory ground-roll. Two different waveform dictionaries using a low Q-factor and a high Q-factor, respectively, are confirmed as able to sparsely represent each component based on their diverse morphologies. Thus, seismic data including body waves and ground-roll can be nonlinearly decomposed into low-oscillatory and high-oscillatory components. This is a new noise attenuation approach according to the oscillatory behaviour of the signal rather than the scale or frequency. We illustrate the method using both synthetic and field shot data. Compared with results from conventional high-pass and f-k filtering, the results of the proposed method prove this method to be effective and advantageous in preserving the waveform and bandwidth of reflections.

The quasiperpendicular environment of large magnetic pulses in Earth's quasiparallel foreshock - ISEE 1 and 2 observations

NASA Technical Reports Server (NTRS)

Greenstadt, E. W.; Moses, S. L.; Coroniti, F. V.; Farris, M. H.; Russell, C. T.

1993-01-01

ULF waves in Earth's foreshock cause the instantaneous angle theta-B(n) between the upstream magnetic field and the shock normal to deviate from its average value. Close to the quasi-parallel (Q-parallel) shock, the transverse components of the waves become so large that the orientation of the field to the normal becomes quasi-perpendicular (Q-perpendicular) during applicable phases of each wave cycle. Large upstream pulses of B were observed completely enclosed in excursions of Theta-B(n) into the Q-perpendicular range. A recent numerical simulation included Theta-B(n) among the parameters examined in Q-parallel runs, and described a similar coincidence as intrinsic to a stage in development of the reformation process of such shocks. Thus, the natural environment of the Q-perpendicular section of Earth's bow shock seems to include an identifiable class of enlarged magnetic pulses for which local Q-perpendicular geometry is a necessary association.

Recent RF Experiments and Application of RF Waves to Real-Time Control of Safety Factor Profile in JT-60U

NASA Astrophysics Data System (ADS)

Suzuki, T.; Isayama, A.; Ide, S.; Fujita, T.; Oikawa, T.; Sakata, S.; Sueoka, M.; Hosoyama, H.; JT-60 Team

2005-09-01

Two topics of applications of RF waves to current profile control in JT-60U are presented; application of lower-hybrid (LH) waves to safety factor profile control and electron cyclotron (EC) waves to neo-classical tearing mode (NTM) control. A real-time control system of safety factor (q) profile was developed. This system, for the first time, enables 1) real time evaluation of q profile using local magnetic pitch angle measurement by motional Stark effect (MSE) diagnostic and 2) control of current drive (CD) location (ρCD) by controlling the parallel refractive index N∥ of LH waves through control of phase difference (Δφ) of LH waves between multi-junction launcher modules. The method for real-time q profile evaluation was newly developed, without time-consuming reconstruction of equilibrium, so that the method requires less computational time. Safety factor profile by the real-time calculation agrees well with that by equilibrium reconstruction with MSE. The control system controls ρCD through Δφ in such a way to decrease the largest residual between the real-time evaluated q profile q(r) and its reference profile qref(r). The real-time control system was applied to a positive shear plasma (q(0)˜1). The reference q profile was set to monotonic positive shear profile having qref(0)=1.3. The real-time q profile approached to the qref(r) during application of real-time control, and was sustained for 3s, which was limited by the duration of the injected LH power. Temporal evolution of current profile was consistent with relaxation of inductive electric field induced by theoretical LH driven current. An m/n=3/2 NTM that appeared at βN˜3 was completely stabilized by ECCD applied to a fully-developed NTM. Precise ECCD at NTM island was essential for the stabilization. ECCD that was applied to resonant rational surface (q=3/2) before an NTM onset suppressed appearance of NTM. In order to keep NTM intensity below a level, ECCD before the mode onset was more effective than that after mode saturation.

GENERAL P, TYPE-I S, AND TYPE-II S WAVES IN ANELASTIC SOLIDS; INHOMOGENEOUS WAVE FIELDS IN LOW-LOSS SOLIDS.

USGS Publications Warehouse

Borcherdt, Roger D.; Wennerberg, Leif

1985-01-01

The physical characteristics for general plane-wave radiation fields in an arbitrary linear viscoelastic solid are derived. Expressions for the characteristics of inhomogeneous wave fields, derived in terms of those for homogeneous fields, are utilized to specify the characteristics and a set of reference curves for general P and S wave fields in arbitrary viscoelastic solids as a function of wave inhomogeneity and intrinsic material absorption. The expressions show that an increase in inhomogeneity of the wave fields cause the velocity to decrease, the fractional-energy loss (Q** minus **1) to increase, the deviation of maximum energy flow with respect to phase propagation to increase, and the elliptical particle motions for P and type-I S waves to approach circularity. Q** minus **1 for inhomogeneous type-I S waves is shown to be greater than that for type-II S waves, with the deviation first increasing then decreasing with inhomogeneity. The mean energy densities (kinetic, potential, and total), the mean rate of energy dissipation, the mean energy flux, and Q** minus **1 for inhomogeneous waves are shown to be greater than corresponding characteristics for homogeneous waves, with the deviations increasing as the inhomogeneity is increased for waves of fixed maximum displacement amplitude.

Phonon-roton modes of liquid 4He beyond the roton in MCM-41

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azuah, Richard T; Omar Diallo, Souleymane; Adams, Mark A.

2013-01-01

We present neutron scattering measurements of the phonon-roton (P-R) mode of superfluid 4He confined in 47 A MCM-41 at T = 0.5 K at wave vectors, Q, beyond the roton wave vector (QR = 1.92 A-1). Measurements beyond the roton require access to high wave vectors (up to Q = 4 A-1) with excellent energy resolution and high statistical precision. The present results show for the first time that at T = 0.5 K the P-R mode in MCM-41 extends out to wave-vector Q 3.6 A-1 with the same energy and zero width (within precision) as observed in bulk superfluidmore » 4He. Layer modes in the roton region are also observed. Specifically, the P-R mode energy, !Q, increases with Q for Q > QR and reaches a plateau at a maximum energy !Q = 2 where is the roton energy, = 0.74 0.01 meV in MCM-41. This upper limit means the P-R mode decays to two rotons when its energy exceeds 2 . It also means that the P-R mode does not decay to two layers modes. If the P-R could decay to two layer modes, !Q would plateau at a lower energy, !Q = 2 L where L = 0.60 meV is the energy of the roton like minimum of the layer mode. The observation of the P-R mode with energy up to 2 shows that the P-R mode and the layer modes are independent modes with apparently little interaction between them.« less

Coenzyme Q10 in Cardiovascular and Metabolic Diseases: Current State of the Problem.

PubMed

Zozina, Vladlena I; Covantev, Serghei; Goroshko, Olga A; Krasnykh, Liudmila M; Kukes, Vladimir G

2018-04-15

The burden of cardiovascular and metabolic diseases is increasing with every year. Although the management of these conditions has improved greatly over the years it is still far from perfect. With all of this in mind, there is a need for new methods of prophylaxis and treatment. Coenzyme Q10 (CoQ10) is an essential compound of the human body. There is growing evidence that CoQ10 is tightly linked to cardiometabolic disorders. Its supplementation can be useful in a variety of chronic and acute disorders. This review analyses the role of CoQ10 in hypertension, ischemic heart disease, myocardial infarction, heart failure, viral myocarditis, cardiomyopathies, cardiac toxicity, dyslipidemia, obesity, type 2 diabetes mellitus, metabolic syndrome, cardiac procedures and resuscitation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Switching dynamics of the spin density wave in superconducting CeCoIn 5

DOE PAGES

Kim, Duk Y.; Lin, Shi-Zeng; Bauer, Eric D.; ...

2017-06-21

The ordering wave vector Q of a spin density wave (SDW), stabilized within the superconducting state of CeCoIn 5 in a high magnetic field, has been shown to be hypersensitive to the direction of the field. Q can be switched from a nodal direction of the d-wave superconducting order parameter to a perpendicular node by rotating the in-plane magnetic field through the antinodal direction within a fraction of a degree. In this paper, we address the dynamics of the switching of Q. We use a free-energy functional based on the magnetization density, which describes the condensation of magnetic fluctuations ofmore » nodal quasiparticles, and show that the switching process includes closing of the SDW gap at one Q and then reopening the SDW gap at another Q perpendicular to the first one. The magnetic field couples to Q through the spin-orbit interaction. Our calculations show that the width of the hysteretic region of switching depends linearly on the deviation of magnetic field from the critical field associated with the SDW transition, consistent with our thermal conductivity measurements. Finally, the agreement between theory and experiment supports our scenario of the hypersensitivity of the Q phase on the direction of magnetic field, as well as the magnon condensation as the origin of the SDW phase in CeCoIn 5.« less

Whistler waves with electron temperature anisotropy and non-Maxwellian distribution functions

NASA Astrophysics Data System (ADS)

Malik, M. Usman; Masood, W.; Qureshi, M. N. S.; Mirza, Arshad M.

2018-05-01

The previous works on whistler waves with electron temperature anisotropy narrated the dependence on plasma parameters, however, they did not explore the reasons behind the observed differences. A comparative analysis of the whistler waves with different electron distributions has not been made to date. This paper attempts to address both these issues in detail by making a detailed comparison of the dispersion relations and growth rates of whistler waves with electron temperature anisotropy for Maxwellian, Cairns, kappa and generalized (r, q) distributions by varying the key plasma parameters for the problem under consideration. It has been found that the growth rate of whistler instability is maximum for flat-topped distribution whereas it is minimum for the Maxwellian distribution. This work not only summarizes and complements the previous work done on the whistler waves with electron temperature anisotropy but also provides a general framework to understand the linear propagation of whistler waves with electron temperature anisotropy that is applicable in all regions of space plasmas where the satellite missions have indicated their presence.

Laser mode conversion into a surface plasma wave in a metal coated optical fiber

NASA Astrophysics Data System (ADS)

Liu, C. S.; Kumar, Gagan; Tripathi, V. K.

2006-07-01

An optical fiber, coated with thin metal film, supports two distinct kinds of waves, viz., body waves that propagate through the fiber as transverse magnetic (TM) and transverse electric modes, and surface plasma waves that propagate on metal free space interface. When the metal has a ripple of suitable wave number q, a body wave of frequency ω and propagation constant kz induces a current at ω ,kz+q in the ripple region that resonantly derives a surface plasma wave. When the metal surface has metallic particles attached to it and molecules are adsorbed on them, the surface plasma wave undergoes surface enhanced Raman scattering with them. The scattered signals propagate backward as a TM body wave and can be detected.

Visual and refractive outcomes of LASIK with the SCHWIND ESIRIS and WaveLight ALLEGRETTO WAVE Eye-q excimer lasers: a prospective, contralateral study.

PubMed

Mearza, Ali A; Muhtaseb, Mohammed; Aslanides, Ioannis M

2008-11-01

To compare the safety, efficacy, and predictability of LASIK with the SCHWIND ESIRIS and WaveLight ALLEGRETTO WAVE Eye-Q excimer laser platforms. This prospective study comprised 44 eyes of 22 consecutive patients who were treated with LASIK using the Moria M2 microkeratome. One eye was treated with the SCHWIND ESIRIS laser and the fellow eye treated with the WaveLight ALLEGRETTO WAVE Eye-Q laser. All eyes operated with the SCHWIND ESIRIS were treated with standard aspheric ablation, whereas the eyes operated with the WaveLight ALLEGRETTO WAVE Eye-Q received treatment with three different ablation types according to the common practice at our clinic. Outcome measures were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, and proximity to target refraction at 6-month follow-up. At 6 months postoperative, mean decimal UCVA was 0.96+/-0.22 (range: 0.3 to 1.2) for ESIRIS eyes and 0.98+/-0.17 (range: 0.6 to 1.2) for ALLEGRETTO eyes (P=.57). Mean postoperative spherical equivalent refraction was -0.02+/-0.28 diopters (D) (range: -0.75 to +0.75 D) for ESIRIS eyes and 0.11+/-0.91 D (range: -1.00 to +3.88 D) for ALLEGRETTO eyes (P=.49). Of the ESIRIS eyes, 20/22 (91%) were within +/-1.00 D of target refraction and 20/22 (91%) were within +/-0.50 D of target refraction. Of the ALLEGRETTO eyes, 20/22 (91%) and 19/22 (86%) were within +/-1.00 D and +/-0.50 D, respectively, of target refraction. No patient lost > or =2 lines of BSCVA in either group. No differences were seen in safety and efficacy outcome parameters between the SCHWIND ESIRIS and WaveLight ALLEGRETTO WAVE Eye-Q excimer lasers when used according to a previously established treatment algorithm at our clinic in the treatment of refractive error.

On the accuracy and precision of numerical waveforms: effect of waveform extraction methodology

NASA Astrophysics Data System (ADS)

Chu, Tony; Fong, Heather; Kumar, Prayush; Pfeiffer, Harald P.; Boyle, Michael; Hemberger, Daniel A.; Kidder, Lawrence E.; Scheel, Mark A.; Szilagyi, Bela

2016-08-01

We present a new set of 95 numerical relativity simulations of non-precessing binary black holes (BBHs). The simulations sample comprehensively both black-hole spins up to spin magnitude of 0.9, and cover mass ratios 1-3. The simulations cover on average 24 inspiral orbits, plus merger and ringdown, with low initial orbital eccentricities e\\lt {10}-4. A subset of the simulations extends the coverage of non-spinning BBHs up to mass ratio q = 10. Gravitational waveforms at asymptotic infinity are computed with two independent techniques: extrapolation and Cauchy characteristic extraction. An error analysis based on noise-weighted inner products is performed. We find that numerical truncation error, error due to gravitational wave extraction, and errors due to the Fourier transformation of signals with finite length of the numerical waveforms are of similar magnitude, with gravitational wave extraction errors dominating at noise-weighted mismatches of ˜ 3× {10}-4. This set of waveforms will serve to validate and improve aligned-spin waveform models for gravitational wave science.

EVALUATION OF RIGHT AND LEFT VENTRICULAR DIASTOLIC FILLING

PubMed Central

Pasipoularides, Ares

2013-01-01

A conceptual fluid-dynamics framework for diastolic filling is developed. The convective deceleration load (CDL) is identified as an important determinant of ventricular inflow during the E-wave (A-wave) upstroke. Convective deceleration occurs as blood moves from the inflow anulus through larger-area cross-sections toward the expanding walls. Chamber dilatation underlies previously unrecognized alterations in intraventricular flow dynamics. The larger the chamber, the larger become the endocardial surface and the CDL. CDL magnitude affects strongly the attainable E-wave (A-wave) peak. This underlies the concept of diastolic ventriculoannular disproportion. Large vortices, whose strength decreases with chamber dilatation, ensue after the E-wave peak and impound inflow kinetic energy, averting an inflow-impeding, convective Bernoulli pressure-rise. This reduces the CDL by a variable extent depending on vortical intensity. Accordingly, the filling vortex facilitates filling to varying degrees, depending on chamber volume. The new framework provides stimulus for functional genomics research, aimed at new insights into ventricular remodeling. PMID:23585308

High-dose, single-bolus eptifibatide: a safe and cost-effective alternative to conventional glycoprotein IIb/IIIa inhibitor use for elective coronary interventions.

PubMed

Fischell, Tim A; Attia, Tamer; Rane, Santosh; Salman, Waddah

2006-10-01

Adjunctive pharmacotherapy with eptifibatide, a glycoprotein (GP) IIb/IIIa inhibitor, as an intravenous bolus followed by infusion has been shown to improve outcomes in elective coronary interventions (PCI). However, bleeding complications and costs have limited the routine adoption of this regimen. The goal of this study was to examine the safety, efficacy and cost-effectiveness of high-dose, single-bolus eptifibatide, without post-intervention infusion, in "real-world" patients undergoing elective PCI. We studied 401 patients with stable and unstable angina who were treated with a high-dose (20 mg), single bolus of eptifibatide plus heparin prior to the start of elective PCI. Exclusion criteria included recent MI, stenting of bypass graft(s), rotational atherectomy and/or brachytherapy. The primary study endpoints were major adverse clinical events (MACE), defined as the in-hospital and 30-day incidence of death from any cause, Q-wave or non-Q-wave MI, repeat target vessel revascularization and/or major bleeding complications. Relevant demographic and procedural characteristics included mean age: 66.4 +/- 11.2; male gender: 242/401 (61%); number of vessels treated per patient: 1.46 +/- 0.42; and number of stents deployed per patient: 1.82 +/- 0.65. In-hospital non-Q-wave MI (CPK and/or CPK-MB > 3 times the upper limit of normal) occurred in 7/401 patients (1.75%) and MACE was 2.25%. Major bleeding complications were seen in 2/401 patients (0.49%). There were 4 additional MACE events at 30-day follow up (total MACE and bleeding = 3.25%). The average anticoagulation cost was 66 dollars/patient. Intravenous eptifibatide, administered as a high-dose (20 mg) single-vial bolus, is a safe, effective and highly cost-effective alternative to the conventional regimens of bolus plus prolonged intravenous GP IIb/IIIa inhibitor infusion for patients undergoing elective PCI.

Utility of a novel risk score for prediction of ventricular tachycardia and cardiac death in chronic Chagas disease - the SEARCH-RIO study

PubMed Central

Benchimol-Barbosa, P.R.; Tura, B.R.; Barbosa, E.C.; Kantharia, B.K.

2013-01-01

The SEARCH-RIO study prospectively investigated electrocardiogram (ECG)-derived variables in chronic Chagas disease (CCD) as predictors of cardiac death and new onset ventricular tachycardia (VT). Cardiac arrhythmia is a major cause of death in CCD, and electrical markers may play a significant role in risk stratification. One hundred clinically stable outpatients with CCD were enrolled in this study. They initially underwent a 12-lead resting ECG, signal-averaged ECG, and 24-h ambulatory ECG. Abnormal Q-waves, filtered QRS duration, intraventricular electrical transients (IVET), 24-h standard deviation of normal RR intervals (SDNN), and VT were assessed. Echocardiograms assessed left ventricular ejection fraction. Predictors of cardiac death and new onset VT were identified in a Cox proportional hazard model. During a mean follow-up of 95.3 months, 36 patients had adverse events: 22 new onset VT (mean±SD, 18.4±4‰/year) and 20 deaths (26.4±1.8‰/year). In multivariate analysis, only Q-wave (hazard ratio, HR=6.7; P<0.001), VT (HR=5.3; P<0.001), SDNN<100 ms (HR=4.0; P=0.006), and IVET+ (HR=3.0; P=0.04) were independent predictors of the composite endpoint of cardiac death and new onset VT. A prognostic score was developed by weighting points proportional to beta coefficients and summing-up: Q-wave=2; VT=2; SDNN<100 ms=1; IVET+=1. Receiver operating characteristic curve analysis optimized the cutoff value at >1. In 10,000 bootstraps, the C-statistic of this novel score was non-inferior to a previously validated (Rassi) score (0.89±0.03 and 0.80±0.05, respectively; test for non-inferiority: P<0.001). In CCD, surface ECG-derived variables are predictors of cardiac death and new onset VT. PMID:24270912

Mathematical Development and Computational Analysis of Harmonic Phase-Magnetic Resonance Imaging (HARP-MRI) Based on Bloch Nuclear Magnetic Resonance (NMR) Diffusion Model for Myocardial Motion.

PubMed

Dada, Michael O; Jayeoba, Babatunde; Awojoyogbe, Bamidele O; Uno, Uno E; Awe, Oluseyi E

2017-09-13

Harmonic Phase-Magnetic Resonance Imaging (HARP-MRI) is a tagged image analysis method that can measure myocardial motion and strain in near real-time and is considered a potential candidate to make magnetic resonance tagging clinically viable. However, analytical expressions of radially tagged transverse magnetization in polar coordinates (which is required to appropriately describe the shape of the heart) have not been explored because the physics required to directly connect myocardial deformation of tagged Nuclear Magnetic Resonance (NMR) transverse magnetization in polar geometry and the appropriate harmonic phase parameters are not yet available. The analytical solution of Bloch NMR diffusion equation in spherical geometry with appropriate spherical wave tagging function is important for proper analysis and monitoring of heart systolic and diastolic deformation with relevant boundary conditions. In this study, we applied Harmonic Phase MRI method to compute the difference between tagged and untagged NMR transverse magnetization based on the Bloch NMR diffusion equation and obtained radial wave tagging function for analysis of myocardial motion. The analytical solution of the Bloch NMR equations and the computational simulation of myocardial motion as developed in this study are intended to significantly improve healthcare for accurate diagnosis, prognosis and treatment of cardiovascular related deceases at the lowest cost because MRI scan is still one of the most expensive anywhere. The analysis is fundamental and significant because all Magnetic Resonance Imaging techniques are based on the Bloch NMR flow equations.

MicroRNA-29 regulates myocardial microvascular endothelial cells proliferation and migration in association with IGF1 in type 2 diabetes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Zhenjie; Jiang, Runxia; Yue, Qingcai

Background: In our study, we investigated the expression and function of microRNA-29 in myocardial microvascular endothelial cells (MMEVC) in type 2 diabetic Goto-Kakizaki (GK) rats. Methods: MiR-29 gene expression was compared, by qRT-PCR between diabetic GK rat MMEVC and non-diabetic Wistar rat MMEVC. MiR-29 was downregulated in GK MMEVC and its effect on angiogenic properties of proliferation and migration was examined. Potential downstream target gene of miR-29, insulin growth factor 1 (IGF1), was assessed by dual-luciferase reporter assay, qRT-PCR and western blot in GK MMEVC. IGF1 was also downregulated by siRNA in miR-29-downregulated GK MMEVC. Its effect on miR-29-associated angiogenicmore » regulation on MMEVC proliferation and migration was further investigated. Results: MiR-29 was substantially upregulated in GK MMEVC than in Wistar MMEVC. Transfection of synthetic miR-29 inhibitor successfully downregulate endogenous miR-29 in GK MMEVC, and subsequently promoted angiogenesis by increasing cell proliferation and migration. IGF1 was confirmed to be downstream target gene of miR-29 in GK MMEVC, with its gene and protein expressions both upregulated in miR-29-downregualted GK MMEVC. Conversely, siRNA-mediated IGF1 downregulation reversed the pro-angiogenic effect of miR-29 downregulation in GK MMEVC, as it decreased cell proliferation and migration. Conclusion: Our study suggests that miR-29 downregulation, through its inverse regulation on downstream target of IGF1 gene, is a pro-angiogenic factor in MMEVC in type 2 diabetic rats.« less

Reflection coefficient of qP, qS and SH at a plane boundary between viscoelastic TTI media

NASA Astrophysics Data System (ADS)

Wang, Hongwei; Peng, Suping

2016-01-01

This paper introduces a calculation method for the effective elastic stiffness tensor matrix of the viscous-elastic TTI medium based on the Chapman theory. We then obtain the phase velocity formula and seismic wave polarization formula of the viscous-elastic TTI medium, by solving the Christoffel equation; solve the phase angle of reflection and transmission wave through the numerical method in accordance with the wave slowness ellipsoid; on the basis of this assumption, and assuming that qP, qS and SH waves occurred simultaneously at the viscous-elastic anisotropic interface, establish the sixth-order Zoeppritz equation in accordance with the boundary conditions; establish the models for the upper and lower media which are viscous-elastic HTI, TTI, etc., on the basis of the sixth-order Zoeppritz equation; and study the impact of fracture dip angle, azimuth angle and frequency on the reflection coefficient. From this we obtain the following conclusions: the reflection coefficient can identify the fracture strike and dip when any information pertaining to the media is unknown; dispersion phenomenon is obvious on the axial plane of symmetry and weakened in the plane vertical to the axial plane of symmetry; the vertical-incidence longitudinal wave can stimulate the qS wave when the dip angle is not 0° or 90° under the condition of coincidence between the symmetry planes of the upper and lower media; when the symmetry planes of the upper and lower media do not coincide and the dip angle is not 0° or 90°, then the vertical-incidence qP will stimulate the qS and SH waves at the same time; the dip angle can cause the reflection coefficient curve to have a more obvious dispersion phenomenon, while the included angle between the symmetry planes of the upper and lower media will weaken the dispersion except SH; and the intercept of reflection coefficient is affected by the fracture dip and included angle between the symmetry planes of the upper and lower media.

Impact of impaired coronary flow reserve and insulin resistance on myocardial energy metabolism in patients with syndrome X.

PubMed

Bøtker, H E; Sonne, H S; Bagger, J P; Nielsen, T T

1997-06-15

To evaluate the role of a decreased coronary flow reserve in the genesis of angina pectoris in patients with syndrome X, we studied myocardial hemodynamics and metabolism at rest, during pace stress, and in the recovery period after pacing in 18 consecutive patients with syndrome X and in 10 control subjects. By means of positron emission tomography or the intracoronary flow-wire method, patients were subclassified as having microvascular angina (MA, n = 8) when coronary flow reserve was reduced (<2.5) or no microvascular angina (non-MA, n = 10) when coronary flow reserve was preserved (> or =2.5). At rest, coronary sinus blood flow was increased in MA patients. During pace stress, coronary sinus blood flow increased by 39 +/- 6% in MA patients versus 67 +/- 12% in non-MA patients and 69 +/- 7% in controls (p <0.05). Patients with non-MA revealed fasting hyperinsulinemia, increased arterial concentration of free fatty acids, and a similar tendency for beta-hydroxybutyrate. Oxygen extraction and carbon dioxide release did not differ between groups. Net myocardial lactate release was not observed in any patient during pace stress and myocardial energy metabolism was preserved in all patients with syndrome X. During pacing, myocardial uptake of free fatty acids and beta-hydroxybutyrate was increased in non-MA patients. Myocardial uptake of free fatty acids correlated positively and myocardial glucose and lactate uptake correlated inversely with arterial concentrations of free fatty acids in all subjects. Metabolic evidence of myocardial ischemia is uncommon in patients with syndrome X, irrespective of a globally reduced coronary flow reserve. Although patients with syndrome X can be subclassified according to presence of a microvascular or a metabolic disorder, angina pectoris and ST-segment depressions coexist with a preserved global myocardial energy efficiency in all patients.

Analysis of dispersion and attenuation of surface waves in poroelastic media in the exploration-seismic frequency band

USGS Publications Warehouse

Zhang, Y.; Xu, Y.; Xia, J.

2011-01-01

We analyse dispersion and attenuation of surface waves at free surfaces of possible vacuum/poroelastic media: permeable-'open pore', impermeable-'closed pore' and partially permeable boundaries, which have not been previously reported in detail by researchers, under different surface-permeable, viscous-damping, elastic and fluid-flowing conditions. Our discussion is focused on their characteristics in the exploration-seismic frequency band (a few through 200 Hz) for near-surface applications. We find two surface-wave modes exist, R1 waves for all conditions, and R2 waves for closed-pore and partially permeable conditions. For R1 waves, velocities disperse most under partially permeable conditions and least under the open-pore condition. High-coupling damping coefficients move the main dispersion frequency range to high frequencies. There is an f1 frequency dependence as a constant-Q model for attenuation at high frequencies. R1 waves for the open pore are most sensitive to elastic modulus variation, but least sensitive to tortuosities variation. R1 waves for partially permeable surface radiate as non-physical waves (Im(k) < 0) at low frequencies. For R2 waves, velocities are slightly lower than the bulk slow P2 waves. At low frequencies, both velocity and attenuation are diffusive of f1/2 frequency dependence, as P2 waves. It is found that for partially permeable surfaces, the attenuation displays -f1 frequency dependence as frequency increasing. High surface permeability, low-coupling damping coefficients, low Poisson's ratios, and low tortuosities increase the slope of the -f1 dependence. When the attenuation coefficients reach 0, R2 waves for partially permeable surface begin to radiate as non-physical waves. ?? 2011 The Authors Geophysical Journal International ?? 2011 RAS.

Attention in western Nevada: Preliminary results from earthquake and explosion sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hough, S.E.; Anderson, J.G.; Patton, H.J.

1989-02-01

We present preliminary results from a study of the attenuation of regional seismic waves at frequencies between 1 and 15 Hz and distances up to 250 km in Western Nevada. Following the methods of Anderson and Hough (1984) and Hough et al. (1988), we parameterize the asymptote of the high frequency acceleration spectrum by the two-parameter model. We relate the model parameters to a two-layer model for Q/sub i/ and Q/sub d/, the freuqency-independent and the frequency dependent components of the quality factor. We compare our results to previously published Q studies in the Basin and Range and find thatmore » our estimate of total Q, Q/sub t/, in the shallow crust is consistent with shear wave Q at close distances with previous estimates of coda Q (Singh and Hermann, 1983) and LgQ (Chavez and Priestley, 1986), suggesting that both coda Q and LgQ are insensitive to near-surface contributions to attenuation.« less

Observation of spin waves in Pd(1. 5% Fe). Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lynn, J.W.; Rhyne, J.J.; Budnick, J.I.

1982-01-01

Inelastic neutron scattering measurements have been carried out on the giant-moment alloy system Pd(1.5% Fe), which is in the dilute ferromagnetic regime. Below the Curie temperature of 67K, relatively well-defined spin-wave excitations have been observed in the small wavevector region (Q < 0.14/A). The dispersion of these excitations is consistent with the quadratic relation E = D(Q/sup 2/) expected for an isotropic ferromagnet, with D = 40 meV-(A/sup 2/) at a temperature of the 40K. With increasing temperature, the spin waves are found to renormalize in energy, and broaden rapidly both with increasing Q and increasing temperature.

Neonatal hypocalcemia, neonatal seizures, and intellectual disability in 22q11.2 deletion syndrome

PubMed Central

Cheung, Evelyn Ning Man; George, Susan R.; Andrade, Danielle M.; Chow, Eva W. C.; Silversides, Candice K.; Bassett, Anne S.

2015-01-01

Purpose Hypocalcemia is a common endocrinological condition in 22q11.2 deletion syndrome. Neonatal hypocalcemia may affect neurodevelopment. We hypothesized that neonatal hypocalcemia would be associated with rare, more severe forms of intellectual disability in 22q11.2 deletion syndrome. Methods We used a logistic regression model to investigate potential predictors of intellectual disability severity, including neonatal hypocalcemia, neonatal seizures, and complex congenital heart disease, e.g., interrupted aortic arch, in 149 adults with 22q11.2 deletion syndrome. Ten subjects had moderate-to-severe intellectual disability. Results The model was highly significant (P < 0.0001), showing neonatal seizures (P = 0.0018) and neonatal hypocalcemia (P = 0.047) to be significant predictors of a more severe level of intellectual disability. Neonatal seizures were significantly associated with neonatal hypocalcemia in the entire sample (P < 0.0001), regardless of intellectual level. There was no evidence for the association of moderate- to-severe intellectual disability with other factors such as major structural brain malformations in this sample. Conclusion The results suggest that neonatal seizures may increase the risk for more severe intellectual deficits in 22q11.2 deletion syndrome, likely mediated by neonatal hypocalcemia. Neonatal hypocalcemia often remains unrecognized until the postseizure period, when damage to neurons may already have occurred. These findings support the importance of early recognition and treatment of neonatal hypocalcemia and potentially neonatal screening for 22q11.2 deletions. PMID:23765047

Being active after your heart attack

MedlinePlus

... the management of patients with unstable angina/non-ST-Elevation myocardial infarction: a report of the American ... the Management of Patients With Unstable Angina/Non-ST-Elevation Myocardial Infarction) developed in collaboration with the ...

Fractional flow reserve of non-culprit vessel post-myocardial infarction: is it reliable?

PubMed

Leite, Luís; Moura Ferreira, Joana; Silva Marques, João; Jorge, Elisabete; Matos, Vítor; Guardado, Jorge; Calisto, João; Pego, Mariano

2015-10-14

Multi-vessel disease is frequent in patients presenting with myocardial infarction and have an important prognostic impact. The decision to proceed to revascularization in non-culprit vessels can be postponed until ischemia is proven in non-invasive stress tests. On the other hand, there is an increasing evidence to support the role of fractional flow reserve (FFR) in acute coronary syndrome setting. We report a case in which a FFR-guided strategy for non-culprit vessels, 3 weeks after an ST-segment elevation myocardial infarction, was followed by a short-term sub-occlusion of the evaluated vessel. The timing of the coronary microcirculation recovery post-myocardial infarction, avoiding a possible false negative FFR, and the diagnostic gaps between ischemia and plaque vulnerability are under discussion. An FFR-guided strategy in this setting should be interpreted with caution.

Preschoolers’ Emotion Knowledge and the Differential Effects of Harsh Punishment

PubMed Central

Berzenski, Sara R.; Yates, Tuppett M.

2013-01-01

This study examined the influence of caregiver-reported harsh physical and verbal punishment on children’s behavioral and self-system adjustment. Children’s emotion knowledge was evaluated as a heretofore unrecognized moderator of these relations. Two hundred fifty preschool age children (50% female; Mage=49.06 months) from diverse backgrounds (50% Hispanic, 18% African American, 10.4% Caucasian, 21.6% Multiracial/Other) were assessed through teacher, caregiver, self, and observer report in the domains of harsh punishment (Parent Child Conflict Tactics Scale), conduct problems (Teacher Report Form, California Child Q-Sort), self concept (Self Description Questionnaire for Preschoolers, California Child Q-Sort), and emotion knowledge (Kuschè Emotion Inventory). Emotion knowledge moderated the relation between harsh punishment and child adjustment. Harsh physical punishment was associated with conduct problems for children with higher emotion knowledge, especially for boys. Harsh verbal punishment was associated with self concept deficits among children with higher emotion knowledge, especially for girls. These relations were also specifically applicable to non-Hispanic children. These results highlight the importance of investigating hypothesis driven interactive effects and the specificity of experience to understand the psychosocial sequelae of parenting practices broadly, and to clarify the mixed evidence in the punishment literature specifically. Clinical implications point to the salience of emotion processes in parent-child disciplinary interventions for understanding the prevalence and pattern of child behavioral adjustment and self concept, as well as more broadly to the role of individual differences in children’s responses to adversity and subsequent therapeutic needs. PMID:23750528

Wave Phenomena in an Acoustic Resonant Chamber

ERIC Educational Resources Information Center

Smith, Mary E.; And Others

1974-01-01

Discusses the design and operation of a high Q acoustical resonant chamber which can be used to demonstrate wave phenomena such as three-dimensional normal modes, Q values, densities of states, changes in the speed of sound, Fourier decomposition, damped harmonic oscillations, sound-absorbing properties, and perturbation and scattering problems.…

Quark fragmentation into spin-triplet S -wave quarkonium

DOE PAGES

Bodwin, Geoffrey T.; Chung, Hee Sok; Kim, U-Rae; ...

2015-04-08

We compute fragmentation functions for a quark to fragment to a quarkonium through an S-wave spin-triplet heavy quark-antiquark pair. We consider both color-singlet and color-octet heavy quark-antiquark (Q (Q) over bar) pairs. We give results for the case in which the fragmenting quark and the quark that is a constituent of the quarkonium have different flavors and for the case in which these quarks have the same flavors. Our results for the sum over all spin polarizations of the Q (Q) over bar pairs confirm previous results. Our results for longitudinally polarized Q (Q) over bar pairs agree with previousmore » calculations for the same flavor cases and correct an error in a previous calculation for the different-flavor case.« less

Preejection period can be calculated using R peak instead of Q.

PubMed

Seery, Mark D; Kondrak, Cheryl L; Streamer, Lindsey; Saltsman, Thomas; Lamarche, Veronica M

2016-08-01

Preejection period (PEP) is a common measure of sympathetic nervous system activation in psychophysiological research, which makes it important to measure reliably for as many participants as possible. PEP is typically calculated as the interval between the onset or peak of the electrocardiogram Q wave and the impedance cardiography B point, but the Q wave can lack clear definition and even its peak is not visible for all participants. We thus investigated the feasibility of using the electrocardiogram R wave peak (Rpeak ) instead of Q because it can be consistently identified with ease and precision. Across four samples (total N = 408), young adult participants completed a variety of minimally metabolically demanding laboratory tasks after a resting baseline. Results consistently supported a close relationship between absolute levels of the Rpeak -B interval and PEP (accounting for approximately 90% of the variance at baseline and 89% during task performance, on average), but for reactivity values, Rpeak -B was practically indistinguishable from PEP (accounting for over 98% of the variance, on average). Given that using Rpeak rather than the onset or peak of Q saves time, eliminates potential subjectivity, and can be applied to more participants (i.e., those without a visible Q wave), findings suggest that Rpeak -B likely provides an adequate estimate of PEP when absolute levels are of interest and clearly does so for within-person changes. © 2016 Society for Psychophysiological Research.

Wave intensity analysis and its application to the coronary circulation

PubMed Central

Davies, JE; Escaned, JE; Hughes, A; Parker, K

Wave intensity analysis (WIA) is a technique developed from the field of gas dynamics that is now being applied to assess cardiovascular physiology. It allows quantification of the forces acting to alter flow and pressure within a fluid system, and as such it is highly insightful in ascribing cause to dynamic blood pressure or velocity changes. When co-incident waves arrive at the same spatial location they exert either counteracting or summative effects on flow and pressure. WIA however allows waves of different origins to be measured uninfluenced by other simultaneously arriving waves. It therefore has found particular applicability within the coronary circulation where both proximal (aortic) and distal (myocardial) ends of the coronary artery can markedly influence blood flow. Using these concepts, a repeating pattern of 6 waves has been consistently identified within the coronary arteries, 3 originating proximally and 3 distally. Each has been associated with a particular part of the cardiac cycle. The most clinically relevant wave to date is the backward decompression wave, which causes the marked increase in coronary flow velocity observed at the start of the diastole. It has been proposed that this wave is generated by the elastic re-expansion of the intra-myocardial blood vessels that are compressed during systolic contraction. Particularly by quantifying this wave, WIA has been used to provide mechanistic and prognostic insight into a number of conditions including aortic stenosis, left ventricular hypertrophy, coronary artery disease and heart failure. It has proven itself to be highly sensitive and as such a number of novel research directions are encouraged where further insights would be beneficial. PMID:28971104

Non-Compact Cardiomyopathy or Ventricular Non-Compact Syndrome?

PubMed Central

2014-01-01

Ventricular myocardial non-compaction has been recognized and defined as a genetic cardiomyopathy by American Heart Association since 2006. The argument on the nomenclature and pathogenesis of this kind of ventricular myocardial non-compaction characterized by regional ventricular wall thickening and deep trabecular recesses often complicated with chronic heart failure, arrhythmia and thromboembolism and usually overlap the genetics and phenotypes of other kind of genetic or mixed cardiomyopathy still exist. The proper classification and correct nomenclature of the non-compact ventricles will contribute to the precisely and completely understanding of etiology and its related patho-physiological mechanism for a better risk stratification and more personalized therapy of the disease individually. All of the genetic heterogeneity and phenotypical overlap and the variety in histopathological, electromechanical and clinical presentation indicates that some of the cardiomyopathies might just be the different consequence of myocardial development variations related to gene mutation and phenotype of one or group genes induced by the interacted and disturbed process of gene modulation at different links of gene function expression and some other etiologies. This review aims to establish a new concept of "ventricular non-compaction syndrome" based on the demonstration of the current findings of etiology, epidemiology, histopathology and echocardiography related to the disorder of ventricular myocardial compaction and myocardial electromechanical function development. PMID:25580189

Balneotherapy and coenzyme Q10 in clinical and experimental medicine.

PubMed

Gvozdjakova, Anna; Kucharska, Jarmila; Sykora, L'ubomir; Singh, Ram B

2014-01-01

Balneotherapy or Spa therapy is used in neurological, cardiovascular, musculoskeletal, dermatological and gynecological diseases, in infertility as well as in metabolic disturbances. Beneficial effects of balneotherapy at the metabolic level is not fully understood. Authors have documented enhancement of antioxidants concentrations (coenzyme Q10- CoQ(10-OX) and alpha-tocopherol) of women with gynecological diseases by treatment with natural mineral water (Spa Lucky balneotherapy, Slovakia). In an experiment with rats, drinking of Spa Lucky mineral water decreased oxidative stress and enhanced concentrations of antioxidants CoQ(9-OX), CoQ(10-OX) in the myocardium, and alpha-tocopherol in uterus, ovaries and myocardium. Drinking of Spa Lucky water by rats stimulated myocardial mitochondrial respiration and energy production, and diminished skeletal muscle mitochondrial function. Simultaneous ingestion of coenzyme Q10 with drinking spa water returned mitochondrial parameters to the values of the control group. This pilot study helps explain the role of antioxidants, oxidative stress and mitochondrial energy production in beneficial effects of Spa Lucky balneotherapy.

Glycoprotein IIb/IIIa inhibitors in patients with unstable angina/non-ST-segment elevation myocardial infarction: appropriate interpretation of the guidelines.

PubMed

Antman, Elliott M

2003-10-01

In 2002, the American College of Cardiology and the American Heart Association published an update to their guidelines for the management of patients with unstable angina and non-ST-segment elevation myocardial infarction. These revised guidelines make specific recommendations regarding the use of glycoprotein IIb/IIIa inhibitors. This article briefly reviews the evidence supporting the use of glycoprotein IIb/IIIa inhibitors in unstable angina and non-ST-segment elevation myocardial infarction, before moving on to discuss interpretation of these new guidelines.

Randomised comparison of drug-eluting versus bare-metal stenting in patients with non-ST elevation myocardial infarction.

PubMed

Remkes, Wouter S; Badings, Erik A; Hermanides, Renicus S; Rasoul, Saman; Dambrink, Jan-Henk E; Koopmans, Petra C; The, Salem Hk; Ottervanger, Jan Paul; Gosselink, A T Marcel; Hoorntje, Jan Ca; Suryapranata, Harry; van 't Hof, Arnoud Wj

2016-01-01

The superiority of drug-eluting stents (DES) over bare-metal stents (BMS) in patients with ST elevation myocardial infarction (STEMI) is well studied; however, randomised data in patients with non-ST elevation myocardial infarction (NSTEMI) are lacking. The objective of this study was to investigate whether stenting with everolimus-eluting stents (EES) safely reduces restenosis in patients with NSTEMI as compared to BMS. ELISA-3 patients were asked to participate in the angiographic substudy and were randomised to DE (Xience V) or BM (Vision) stenting (ELISA-3 group). The primary end point was minimal luminal diameter (MLD) at 9-month follow-up angiography. In addition, 296 patients with NSTEMI who were excluded or did not want to participate in the ELISA-3 trial (RELI group) were randomised to DE or BM stenting and underwent clinical follow-up only (major adverse cardiac events (MACE), stent thrombosis (ST)). A pooled analysis was performed to assess an effect on clinical outcome. 178 of 540 ELISA-3 patients participated in the angiographic substudy. MLD at 9 months angiography was 2.37±0.63 mm (DES) versus 1.84±0.62 mm (BMS), p<0.001. Binary restenosis occurred in 1.9% in the DES group versus 16.7% in the BMS group (RR 0.11, 95% CI 0.02 to 0.84, p=0.007). In the pooled analysis, the incidence of MACE, target vessel revascularisation and ST at 2 years follow-up in the DES versus BMS group was 12.5% versus 16.0% (p=0.28), 4.0% versus 10.4% (p=0.009) and 1.3% versus 3.0% (p=0.34), respectively. In patients with NSTEMI, use of EES is safe and decreases both angiographic and clinical restenosis as compared to BMS http://www.isrctn.com/search?q=39230163. 39230163; Post-results.

Randomised comparison of drug-eluting versus bare-metal stenting in patients with non-ST elevation myocardial infarction

PubMed Central

Remkes, Wouter S; Badings, Erik A; Hermanides, Renicus S; Rasoul, Saman; Dambrink, Jan-Henk E; Koopmans, Petra C; The, Salem HK; Ottervanger, Jan Paul; Gosselink, A T Marcel; Hoorntje, Jan CA; Suryapranata, Harry; van 't Hof, Arnoud WJ

2016-01-01

Objective The superiority of drug-eluting stents (DES) over bare-metal stents (BMS) in patients with ST elevation myocardial infarction (STEMI) is well studied; however, randomised data in patients with non-ST elevation myocardial infarction (NSTEMI) are lacking. The objective of this study was to investigate whether stenting with everolimus-eluting stents (EES) safely reduces restenosis in patients with NSTEMI as compared to BMS. Methods ELISA-3 patients were asked to participate in the angiographic substudy and were randomised to DE (Xience V) or BM (Vision) stenting (ELISA-3 group). The primary end point was minimal luminal diameter (MLD) at 9-month follow-up angiography. In addition, 296 patients with NSTEMI who were excluded or did not want to participate in the ELISA-3 trial (RELI group) were randomised to DE or BM stenting and underwent clinical follow-up only (major adverse cardiac events (MACE), stent thrombosis (ST)). A pooled analysis was performed to assess an effect on clinical outcome. Results 178 of 540 ELISA-3 patients participated in the angiographic substudy. MLD at 9 months angiography was 2.37±0.63 mm (DES) versus 1.84±0.62 mm (BMS), p<0.001. Binary restenosis occurred in 1.9% in the DES group versus 16.7% in the BMS group (RR 0.11, 95% CI 0.02 to 0.84, p=0.007). In the pooled analysis, the incidence of MACE, target vessel revascularisation and ST at 2 years follow-up in the DES versus BMS group was 12.5% versus 16.0% (p=0.28), 4.0% versus 10.4% (p=0.009) and 1.3% versus 3.0% (p=0.34), respectively. Conclusions In patients with NSTEMI, use of EES is safe and decreases both angiographic and clinical restenosis as compared to BMS http://www.isrctn.com/search?q=39230163. Trial registration number 39230163; Post-results. PMID:27933192

Difference in the Clinical Characteristics of Ventricular Fibrillation Occurrence in the Early Phase of an Acute Myocardial Infarction Between Patients With and Without J Waves.

PubMed

Naruse, Yoshihisa; Nogami, Akihiko; Harimura, Yoshie; Ishibashi, Mayu; Noguchi, Yuichi; Sekiguchi, Yukio; Sato, Akira; Aonuma, Kazutaka

2015-08-01

We recently showed that the presence of J waves increases the risk of ventricular fibrillation (VF) occurrence in the early phase of an acute myocardial infarction (AMI). This study aimed to evaluate the clinical characteristics of VF occurrences in the early phase of an AMI between patients with and without J waves. This retrospective, observational study included 281 consecutive patients with an AMI (69 ± 12 years; 207 men) in whom 12-lead ECGs before AMI onset could be evaluated. The patients were classified based on a VF occurrence <48 hours after AMI onset and the presence of J waves. J waves were electrocardiographically defined as an elevation of the terminal portion of the QRS complex of >0.1 mV from baseline in at least 2 contiguous inferior or lateral leads. VF occurred in 24 patients, and J waves were present in 37. VF occurrence was more prevalent in the patients with than without J waves (27% vs. 6%; P < 0.001). Among the 244 patients without J waves, peak creatine kinase level (P < 0.01), number of diseased coronary arteries (P < 0.01), and male sex (P < 0.05) were higher in the patients with than without VF occurrence. However, among the 37 patients with J waves, there was no significant difference in these variables. There was no association between the location of J waves and the infarct area. In patients with AMI, those with J waves were more likely to develop VF and less likely to have high-risk clinical characteristics than those without J waves. © 2015 Wiley Periodicals, Inc.

A novel approach to gravitation from fluid theory: Titius-Bode structures, flat rotation rate of galaxies, and other predictions

NASA Astrophysics Data System (ADS)

Munera, Hector A.

Following the discovery of quantum phenomena at laboratory scale (Couder & Fort 2006), de Broglie pilot wave theory (De Broglie 1962) has been revived under a hydrodynamic guise (Bush 2015). Theoretically, it boils down to solving the transport equations for the energy and linear momentum densities of a postulated fundamental fluid in terms of classical wave equations, which inherently are Lorentz-invariant and scale-invariant. Instead of the conventional harmonic solutions, for astronomical and gravitational problems the novel solutions for the homogeneous wave equation in spherical coordinates are more suitable (Munera et al. 1995, Munera & Guzman 1997, and Munera 2000). Two groups of solutions are particularly relevant: (a) The inherently-quantized helicoidal solutions that may be applicable to describe spiral galaxies, and (b) The non-harmonic solutions with time (t) and distance (r) entangled in the single variable q = Ct/r (C is the two-way local electromagnetic speed). When these functions are plotted against 1/q they manifestly depict quantum effects in the near field, and Newtonian-like gravity in the far-field. The near-field predicts quantized effects similar to ring structures and to Titius-Bode structures, both in our own solar system and in exoplanets, the correlation between predicted and observed structures being typically larger than 99 per cent. In the far-field, some non-harmonic functions have a rate of decrement with distance slower than inverse-square thus explaining the flat rotation rate of galaxies. Additional implications for Trojan orbits, and quantized effects in photon deflection were also noted.

Long-term follow-up of DDD and VDD pacing: a prospective non-randomized single-centre comparison of patients with symptomatic atrioventricular block.

PubMed

Marchandise, Sébastien; Scavée, Christophe; le Polain de Waroux, Jean-Benoit; de Meester, Christophe; Vanoverschelde, Jean-Louis; Debbas, Nadia

2012-04-01

This prospective non-randomized single-centre registry compared clinical outcome, pacing parameters, and long-term survival in patients receiving VDD or DDD pacemaker (PMs) for symptomatic atrioventricular (AV) block. Single-lead VDD (n= 166) and DDD (n= 254) PMs were implanted in 420 successive patients with isolated AV block between January 2001 and December 2009. At the end of the follow-up period [median 25 (1-141) months], there was no difference in the incidence of atrial fibrillation [11.2% in the VDD group; 11.4% in the DDD group (P= 0.95)], myocardial infarction [31.1% in the VDD group; 25.2% in the DDD group (P= 0.20)], or dilated cardiomyopathy [9.9% in the VDD group; 8.9% in the DDD group (P= 0.74)]. At last follow-up, 65.9% of the VDD PMs and 89.3% of the DDD PMs were still programmed in their original mode with good atrial sensing. Due to permanent atrial fibrillation, 7.9% patients out of the VDD group had been switched to VVIR mode and 8.7% patients out of the DDD group to VVIR or DDIR mode. The P-wave amplitude was poor (sensed P-wave <0.5 mV) in 19.1% of the VDD PM and 1.6% of the DDD PM (P< 0.001) and 7.1% of the VDD patients and 0.4% of the DDD patients had been switched to VVIR pacing mode due to P-wave undersensing and AV dissociation (P= 0.003). Symptomatic atrial undersensing requiring upgrading was similar in both groups. The overall survival, adjusted for age, was not significantly different in the VDD and the DDD group (log rank: 0.26). Moreover, Cox survival analysis excluded the pacing mode as a significant predictor of mortality [hazard ratio (HR) = 0.79, confidence interval (CI) (0.46-1.35), P= 0.39]. Comparing VDD and DDD pacing, a significantly larger number of VDD-paced patients developed poor atrial signal detection without clinical impact. However, atrial under sensing did not influence the incidence of atrial fibrillation, myocardial infarction, dilated cardiomyopathy, or mortality.

Is the coexistence of sustained ST-segment elevation and abnormal Q waves a risk factor for electrical storm in implanted cardioverter defibrillator patients with structural heart diseases?

PubMed

Furushima, Hiroshi; Chinushi, Masaomi; Iijima, Kenichi; Hasegawa, Kanae; Sato, Akinori; Izumi, Daisuke; Watanabe, Hiroshi; Aizawa, Yoshifusa

2012-05-01

The aim of this study was to determine whether or not the coexistence of sustained ST-segment elevation and abnormal Q waves (STe-Q) could be a risk factor for electrical storm (ES) in implanted cardioverter defibrillator (ICD) patients with structural heart diseases. In all, 156 consecutive patients received ICD therapy for secondary prevention of sudden cardiac death and/or sustained ventricular tachyarrhythmias were included. Electrical storm was defined as ≥3 separate episodes of ventricular tachycardia (VT) and/or ventricular fibrillation (VF) terminated by ICD therapies within 24 h. During a mean follow-up of 1825 ± 1188 days, 42 (26.9%) patients experienced ES, of whom 12 had coronary artery disease, 15 had idiopathic dilated cardiomyopathy, 6 had hypertrophic cardiomyopathy, 4 had arrhythmogenic right ventricular cardiomyopathy, 4 had cardiac sarcoidosis, and 1 had valvular heart disease. Sustained ST-segment elevation and abnormal Q waves in ≥2 leads on the 12-lead electrocardiography was observed in 33 (21%) patients. On the Kaplan-Meier analysis, patients with STe-Q had a markedly higher risk of ES than those without STe-Q (P< 0.0001). The multivariate Cox proportional hazards regression model indicated that STe-Q and left ventricular ejection fraction (LVEF) (<30%) were independent risk factors associated with the recurrence of VT/VF (STe-Q: HR 1.962, 95% CI 1.24-3.12, P= 0.004; LVEF: HR 1.860, 95% CI 1.20-2.89, P= 0.006), and STe-Q was an independent risk factor associated with ES (HR 4.955, 95% CI 2.69-9.13, P< 0.0001). Sustained ST-segment elevation and abnormal Q waves could be a risk factor of not only recurrent VT/VF but also ES in patients with structural heart diseases.

New imaging technology: measurement of myocardial perfusion by contrast echocardiography

NASA Technical Reports Server (NTRS)

Rubin, D. N.; Thomas, J. D.

2000-01-01

Myocardial perfusion imaging has long been a goal for the non-invasive echocardiographic assessment of the heart. However, many factors at play in perfusion imaging have made this goal elusive. Harmonic imaging and triggered imaging with newer contrast agents have made myocardial perfusion imaging potentially practical in the very near future. The application of indicator dilution theory to the coronary circulation and bubble contrast agents is fraught with complexities and sources of error. Therefore, quantification of myocardial perfusion by non-invasive echocardiographic imaging requires further investigation in order to make this technique clinically viable.

Regional acidosis locally inhibits but remotely stimulates Ca2+ waves in ventricular myocytes

PubMed Central

Ford, Kerrie L.; Moorhouse, Emma L.; Bortolozzi, Mario; Richards, Mark A.; Swietach, Pawel; Vaughan-Jones, Richard D.

2017-01-01

Abstract Aims Spontaneous Ca2+ waves in cardiomyocytes are potentially arrhythmogenic. A powerful controller of Ca2+ waves is the cytoplasmic H+ concentration ([H+]i), which fluctuates spatially and temporally in conditions such as myocardial ischaemia/reperfusion. H+-control of Ca2+ waves is poorly understood. We have therefore investigated how [H+]i co-ordinates their initiation and frequency. Methods and results Spontaneous Ca2+ waves were imaged (fluo-3) in rat isolated ventricular myocytes, subjected to modest Ca2+-overload. Whole-cell intracellular acidosis (induced by acetate-superfusion) stimulated wave frequency. Pharmacologically blocking sarcolemmal Na+/H+ exchange (NHE1) prevented this stimulation, unveiling inhibition by H+. Acidosis also increased Ca2+ wave velocity. Restricting acidosis to one end of a myocyte, using a microfluidic device, inhibited Ca2+ waves in the acidic zone (consistent with ryanodine receptor inhibition), but stimulated wave emergence elsewhere in the cell. This remote stimulation was absent when NHE1 was selectively inhibited in the acidic zone. Remote stimulation depended on a locally evoked, NHE1-driven rise of [Na+]i that spread rapidly downstream. Conclusion Acidosis influences Ca2+ waves via inhibitory Hi+ and stimulatory Nai+ signals (the latter facilitating intracellular Ca2+-loading through modulation of sarcolemmal Na+/Ca2+ exchange activity). During spatial [H+]i-heterogeneity, Hi+-inhibition dominates in acidic regions, while rapid Nai+ diffusion stimulates waves in downstream, non-acidic regions. Local acidosis thus simultaneously inhibits and stimulates arrhythmogenic Ca2+-signalling in the same myocyte. If the principle of remote H+-stimulation of Ca2+ waves also applies in multicellular myocardium, it raises the possibility of electrical disturbances being driven remotely by adjacent ischaemic areas, which are known to be intensely acidic. PMID:28339694

Regional acidosis locally inhibits but remotely stimulates Ca2+ waves in ventricular myocytes.

PubMed

Ford, Kerrie L; Moorhouse, Emma L; Bortolozzi, Mario; Richards, Mark A; Swietach, Pawel; Vaughan-Jones, Richard D

2017-07-01

Spontaneous Ca2+ waves in cardiomyocytes are potentially arrhythmogenic. A powerful controller of Ca2+ waves is the cytoplasmic H+ concentration ([H+]i), which fluctuates spatially and temporally in conditions such as myocardial ischaemia/reperfusion. H+-control of Ca2+ waves is poorly understood. We have therefore investigated how [H+]i co-ordinates their initiation and frequency. Spontaneous Ca2+ waves were imaged (fluo-3) in rat isolated ventricular myocytes, subjected to modest Ca2+-overload. Whole-cell intracellular acidosis (induced by acetate-superfusion) stimulated wave frequency. Pharmacologically blocking sarcolemmal Na+/H+ exchange (NHE1) prevented this stimulation, unveiling inhibition by H+. Acidosis also increased Ca2+ wave velocity. Restricting acidosis to one end of a myocyte, using a microfluidic device, inhibited Ca2+ waves in the acidic zone (consistent with ryanodine receptor inhibition), but stimulated wave emergence elsewhere in the cell. This remote stimulation was absent when NHE1 was selectively inhibited in the acidic zone. Remote stimulation depended on a locally evoked, NHE1-driven rise of [Na+]i that spread rapidly downstream. Acidosis influences Ca2+ waves via inhibitory Hi+ and stimulatory Nai+ signals (the latter facilitating intracellular Ca2+-loading through modulation of sarcolemmal Na+/Ca2+ exchange activity). During spatial [H+]i-heterogeneity, Hi+-inhibition dominates in acidic regions, while rapid Nai+ diffusion stimulates waves in downstream, non-acidic regions. Local acidosis thus simultaneously inhibits and stimulates arrhythmogenic Ca2+-signalling in the same myocyte. If the principle of remote H+-stimulation of Ca2+ waves also applies in multicellular myocardium, it raises the possibility of electrical disturbances being driven remotely by adjacent ischaemic areas, which are known to be intensely acidic. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Cardiology.

Long-term clinical and angiographic results of Sirolimus-Eluting Stent in Complex Coronary Chronic Total Occlusion Revascularization: the SECTOR registry.

PubMed

Galassi, Alfredo R; Tomasello, Salvatore D; Costanzo, Luca; Campisano, Maria B; Barrano, Giombattista; Tamburino, Corrado

2011-10-01

Drug-eluting stents showed a better angiographic and clinical outcome in comparison with bare metal stent in chronic total occlusions (CTOs) percutaneous revascularization, however, great concerns still remain regarding the rate of restenosis and reocclusion in comparison with nonocclusive lesions. To evaluate angiographic and clinical outcomes after sirolimus-eluting stent (SES) implantation in the setting of a "real world" series of complex CTOs. From January 2006 to December 2008, 172 consecutive patients with 179 CTO lesions were enrolled into registry. Among these, successful recanalization was obtained in 144 lesions (80.4%) with exclusive SES implantation in 104 lesions. The 9-12 months angiographic follow-up was executed in 85.5% of lesions with evidence of angiographic binary restenosis in 16.8% of lesions. Total stent length and number of stent implanted were recognized as independent predictors of restenosis (odds ratio [OR] 4.7, 95% confidence interval [CI] 1.28-107.09, P = 0.02) and (OR 5.8, 95% CI 1.39-23.55, P = 0.01), respectively.The 2-year clinical follow-up showed rates of target lesion revascularization, non-Q wave myocardial infarction, and total major adverse cardiovascular events (MACEs) of 11.1%, 2%, and 13.1%, respectively. Cox proportional-hazard analysis showed diabetes as independent predictor of MACEs (hazard ratio [HR] 4.832; 95% CI, 0.730-0.861; P = 0.028). Data from this registry demonstrate the long-term efficacy and safety of SES implantation after complex CTOs recanalization. ©2011, Wiley Periodicals, Inc.

Cost-utility of enoxaparin compared with unfractionated heparin in unstable coronary artery disease

PubMed Central

Nicholson, Tricia; McGuire, Alistair; Milne, Ruairidh

2001-01-01

Background Low molecular weight heparins hold several advantages over unfractionated heparin including convenience of administration. Enoxaparin is one such heparin licensed in the UK for use in unstable coronary artery disease (unstable stable angina and non-Q wave myocardial infarction). In these patients, two large randomised controlled trials and their meta-analysis showed small benefits for enoxaparin over unfractionated heparin at 30–43 days and potentially at one year. We found no relevant published full economic evaluations, only cost studies, one of which was conducted in the UK. The other studies, from the US, Canada and France, are difficult to interpret since their resource use and costs may not reflect UK practice. Methods We aimed to compare the benefits and costs of short-term treatment (two to eight days) with enoxaparin and unfractionated heparin in unstable coronary artery disease. We used published data sources to estimate the incremental cost per quality adjusted life year (QALY), adopting a NHS perspective and using 1998 prices. Results The base case was a 0.013 QALY gain and net cost saving of £317 per person treated with enoxaparin instead of unfractionated heparin. All but one sensitivity analysis showed net savings and QALY gains, the exception (the worst case) being a cost per QALY of £3,305. Best cases were a £495 saving and 0.013 QALY gain, or a £317 saving and 0.014 QALY gain per person. Conclusions Enoxaparin appears cost saving compared with unfractionated heparin in patients with unstable coronary artery disease. However, cost implications depend on local revascularisation practice. PMID:11701090

Interleukin-6 and the Risk of Adverse Outcomes in Patients After an Acute Coronary Syndrome: Observations From the SOLID-TIMI 52 (Stabilization of Plaque Using Darapladib-Thrombolysis in Myocardial Infarction 52) Trial.

PubMed

Fanola, Christina L; Morrow, David A; Cannon, Christopher P; Jarolim, Petr; Lukas, Mary Ann; Bode, Christoph; Hochman, Judith S; Goodrich, Erica L; Braunwald, Eugene; O'Donoghue, Michelle L

2017-10-24

Interleukin-6 (IL-6) is an inflammatory cytokine implicated in plaque instability in acute coronary syndrome (ACS). We aimed to evaluate the prognostic implications of IL-6 post-ACS. IL-6 concentration was assessed at baseline in 4939 subjects in SOLID-TIMI 52 (Stabilization of Plaque Using Darapladib-Thrombolysis in Myocardial Infarction 52), a randomized trial of darapladib in patients ≤30 days from ACS. Patients were followed for a median of 2.5 years for major adverse cardiovascular events; cardiovascular death, myocardial infarction, or stroke) and cardiovascular death or heart failure hospitalization. Primary analyses were adjusted first for baseline characteristics, days from index ACS, ACS type, and randomized treatment arm. For every SD increase in IL-6, there was a 10% higher risk of major adverse cardiovascular events (adjusted hazard ratio [adj HR] 1.10, 95% confidence interval [CI] 1.01-1.19) and a 22% higher risk of cardiovascular death or heart failure (adj HR 1.22, 95% CI 1.11-1.34). Patients in the highest IL-6 quartile had a higher risk of major adverse cardiovascular events (adj HR Q4:Q1 1.57, 95% CI 1.22-2.03) and cardiovascular death or heart failure (adj HR 2.29, 95% CI 1.6-3.29). After further adjustment for biomarkers (high-sensitivity C-reactive protein, lipoprotein-associated phospholipase A 2 activity, high-sensitivity troponin I, and B-type natriuretic peptide), IL-6 remained significantly associated with the risk of major adverse cardiovascular events (adj HR Q4:Q1 1.43, 95% CI 1.09-1.88) and cardiovascular death or heart failure (adj HR 1.79, 95% CI 1.22-2.63). In patients after ACS, IL-6 concentration is associated with adverse cardiovascular outcomes independent of established risk predictors and biomarkers. These findings lend support to the concept of IL-6 as a potential therapeutic target in patients with unstable ischemic heart disease. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

MicroRNAs and cardiac sarcoplasmic reticulum calcium ATPase-2 in human myocardial infarction: expression and bioinformatic analysis.

PubMed

Boštjančič, Emanuela; Zidar, Nina; Glavač, Damjan

2012-10-15

Cardiac sarco(endo)plasmic reticulum calcium ATPase-2 (SERCA2) plays one of the central roles in myocardial contractility. Both, SERCA2 mRNA and protein are reduced in myocardial infarction (MI), but the correlation has not been always observed. MicroRNAs (miRNAs) act by targeting 3'-UTR mRNA, causing translational repression in physiological and pathological conditions, including cardiovascular diseases. One of the aims of our study was to identify miRNAs that could influence SERCA2 expression in human MI. The protein SERCA2 was decreased and 43 miRNAs were deregulated in infarcted myocardium compared to corresponding remote myocardium, analyzed by western blot and microRNA microarrays, respectively. All the samples were stored as FFPE tissue and in RNAlater. miRNAs binding prediction to SERCA2 including four prediction algorithms (TargetScan, PicTar, miRanda and mirTarget2) identified 213 putative miRNAs. TAM and miRNApath annotation of deregulated miRNAs identified 18 functional and 21 diseased states related to heart diseases, and association of the half of the deregulated miRNAs to SERCA2. Free-energy of binding and flanking regions (RNA22, RNAfold) was calculated for 10 up-regulated miRNAs from microarray analysis (miR-122, miR-320a/b/c/d, miR-574-3p/-5p, miR-199a, miR-140, and miR-483), and nine miRNAs deregulated from microarray analysis were used for validation with qPCR (miR-21, miR-122, miR-126, miR-1, miR-133, miR-125a/b, and miR-98). Based on qPCR results, the comparison between FFPE and RNAlater stored tissue samples, between Sybr Green and TaqMan approaches, as well as between different reference genes were also performed. Combing all the results, we identified certain miRNAs as potential regulators of SERCA2; however, further functional studies are needed for verification. Using qPCR, we confirmed deregulation of nine miRNAs in human MI, and show that qPCR normalization strategy is important for the outcome of miRNA expression analysis in human MI.

A Visualization Method for Corrosion Damage on Aluminum Plates Using an Nd:YAG Pulsed Laser Scanning System

PubMed Central

Lee, Inbok; Zhang, Aoqi; Lee, Changgil; Park, Seunghee

2016-01-01

This paper proposes a non-contact nondestructive evaluation (NDE) technique that uses laser-induced ultrasonic waves to visualize corrosion damage in aluminum alloy plate structures. The non-contact, pulsed-laser ultrasonic measurement system generates ultrasonic waves using a galvanometer-based Q-switched Nd:YAG laser and measures the ultrasonic waves using a piezoelectric (PZT) sensor. During scanning, a wavefield can be acquired by changing the excitation location of the laser point and measuring waves using the PZT sensor. The corrosion damage can be detected in the wavefield snapshots using the scattering characteristics of the waves that encounter corrosion. The structural damage is visualized by calculating the logarithmic values of the root mean square (RMS), with a weighting parameter to compensate for the attenuation caused by geometrical spreading and dispersion of the waves. An intact specimen is used to conduct a comparison with corrosion at different depths and sizes in other specimens. Both sides of the plate are scanned with the same scanning area to observe the effect of the location where corrosion has formed. The results show that the damage can be successfully visualized for almost all cases using the RMS-based functions, whether it formed on the front or back side. Also, the system is confirmed to have distinguished corroded areas at different depths. PMID:27999252

A Visualization Method for Corrosion Damage on Aluminum Plates Using an Nd:YAG Pulsed Laser Scanning System.

PubMed

Lee, Inbok; Zhang, Aoqi; Lee, Changgil; Park, Seunghee

2016-12-16

This paper proposes a non-contact nondestructive evaluation (NDE) technique that uses laser-induced ultrasonic waves to visualize corrosion damage in aluminum alloy plate structures. The non-contact, pulsed-laser ultrasonic measurement system generates ultrasonic waves using a galvanometer-based Q-switched Nd:YAG laser and measures the ultrasonic waves using a piezoelectric (PZT) sensor. During scanning, a wavefield can be acquired by changing the excitation location of the laser point and measuring waves using the PZT sensor. The corrosion damage can be detected in the wavefield snapshots using the scattering characteristics of the waves that encounter corrosion. The structural damage is visualized by calculating the logarithmic values of the root mean square (RMS), with a weighting parameter to compensate for the attenuation caused by geometrical spreading and dispersion of the waves. An intact specimen is used to conduct a comparison with corrosion at different depths and sizes in other specimens. Both sides of the plate are scanned with the same scanning area to observe the effect of the location where corrosion has formed. The results show that the damage can be successfully visualized for almost all cases using the RMS-based functions, whether it formed on the front or back side. Also, the system is confirmed to have distinguished corroded areas at different depths.

Cannabidiol limits Tcell-mediated chronic autoimmune myocarditis: implications to autoimmune disorders and organ transplantation.

PubMed

Lee, Wen-Shin; Erdelyi, Katalin; Matyas, Csaba; Mukhopadhyay, Partha; Varga, Zoltan V; Liaudet, Lucas; Haskó, György; Čiháková, Daniela; Mechoulam, Raphael; Pacher, Pal

2016-01-08

Myocarditis is a major cause of heart failure and sudden cardiac death in young adults and adolescents. Many cases of myocarditis are associated with autoimmune processes in which cardiac myosin is a major autoantigen. Conventional immunosuppressive therapies often provide unsatisfactory results and are associated with adverse toxicities during the treatment of autoimmune myocarditis. Cannabidiol (CBD) is a non-psychoactive constituent of Marijuana which exerts antiinflammatory effects independent from classical cannabinoid receptors. Recently 80 clinical trials have been reported investigating the effects of CBD in various diseases from inflammatory bowel disease to graft-versus-host disease. CBD-based formulations are used for the management of multiple sclerosis in numerous countries, and CBD also received FDA approval for the treatment of refractory childhood epilepsy and glioblastoma multiforme. Herein, using a well-established mouse model of experimental autoimmune myocarditis (EAM) induced by immunization with cardiac myosin emmulsified in adjuvant resulting in T cell-mediated inflammation, cardiomyocyte cell death, fibrosis and myocardial dysfunction, we studied the potential beneficial effects of CBD. EAM was characterized by marked myocardial T cell-infiltration, profound inflammatory response, fibrosis (measured by qRT-PCR, histology and immunohistochemistry analyses) accompanied by marked attenuation of both systolic and diastolic cardiac functions measured with pressure-volume conductance catheter technique. Chronic treatment with CBD largely attenuated the CD3+ and CD4+ mediated inflammatory response and injury, myocardial fibrosis and cardiac dysfunction in mice. CBD may represent a promising novel treatment for management of autoimmune myocarditis and possibly other autoimmune disorders, and organ transplantation.

Q10 supplementation effects on cardiac enzyme CK-MB and troponin in patients undergoing coronary artery bypass graft: a randomized, double-blinded, placebo-controlled clinical trial

PubMed Central

Moludi, Jalal; Keshavarz, Seyedali; Tabaee, Ali Sadeghpour; Safiri, Saeid; Pakzad, Reza

2016-01-01

Introduction: Coronary artery bypass surgery (CABG) is associated with ischemia-reperfusion injury and tissue damage. CoQ10 as an antioxidant has an important role and may have cardio-protective effects after myocardial dysfunction and CABG. We aimed to evaluate whether CoQ10 has a myocardial cardio protective impact on cardiac biomarkers after CABG. Methods: In this double-blind study, 80 patients with coronary artery disease (CAD) who underwent CABG surgery were divided into intervention and control groups and received Q10 supplement or placebo, respectively. The surgical characteristics of the patients in the two groups were similar. The intervention group received 150 mg of Q10 supplement per day for 7 days before the surgery. The control group received placebo capsule. After operation the inter- and intra-group blood levels of CK-MB and troponin, before and after supplementation and 12 hours after the CABG, and postoperative outcomes such as intensive care unit (ICU) stay and hospital stay were compared. Results: In this study, 40 subjects were located in each group. The participation rate was 97.5% and men and women accounted for 52.5% and 47.5% respectively. The mean age of the subjects was 58.17 ± 8.55. The two groups were not significantly different in terms of basic variables. Within-group comparison showed a significant increase in the level of troponin enzymes over time (P < 0.001) and CK-MB (P < 0.001). However, between-group comparison showed no significant difference between the two groups in terms of CK-MB (P = 0.384) and troponin (P = 0.115). In the end, no interaction was observed between the intervention and time on CK-MB (P = 0.095) and troponin (P = 0.198) variables. Conclusion: Q10 supplementation 7 days before surgery was not effective in reducing CK-MB and troponin after CABG. PMID:27069560

Fluorescence in situ hybridization analyses of hematologic malignancies reveal frequent cytogenetically unrecognized 12p rearrangements.

PubMed

Andreasson, P; Johansson, B; Billström, R; Garwicz, S; Mitelman, F; Höglund, M

1998-03-01

Thirty-two hematologic malignancies--nine with cytogenetically identified 12p abnormalities and 23 with whole or partial losses of chromosome 12--were selected for fluorescence in situ hybridization (FISH) investigations of 12p. These analyses revealed structural 12p changes, such as translocations, deletions, insertions, inversions and amplification, in 20 cases. ETV6 rearrangements were detected in three acute leukemias. One acute undifferentiated leukemia had t(4;12)(q12;p13) as the sole anomaly. The second case, an acute myeloid leukemia (AML), displayed complex abnormalities involving, among others, chromosomes 9 and 12. The third case, also an AML, had an insertion of the distal part of ETV6 into chromosome arm 11q and into multiple ring chromosomes, which also contained chromosome 11 material, resulting in an amplification of a possible fusion gene. The fusion partners in these cases remain to be identified. Thirty-one additional breakpoints on 12p could be characterized in detail. The majority of these breaks were shown to result in interchromosomal rearrangements, possibly indicating the location of hitherto unrecognized genes of importance in the pathogenesis of hematologic malignancies. The FISH analyses disclosed terminal or interstitial 12p deletions in 18 cases. Seven myeloid malignancies showed deletions restricted to a region, including ETV6 and CDKN1B, which has been reported to be frequently lost in leukemias. In four cases, the deletions involved both these genes, whereas two AML displayed loss of CDKN1B but not ETV6, supporting previously reported findings indicating a region of deletion not including this gene. However, one myelodysplastic syndrome lacked one copy of ETV6 but not CDKN1B. Hence, we suggest a minimal region of deletion on 12p located between the ETV6 and CDKN1B genes.

Basic study on a lower-energy defibrillation method using computer simulation and cultured myocardial cell models.

PubMed

Yaguchi, A; Nagase, K; Ishikawa, M; Iwasaka, T; Odagaki, M; Hosaka, H

2006-01-01

Computer simulation and myocardial cell models were used to evaluate a low-energy defibrillation technique. A generated spiral wave, considered to be a mechanism of fibrillation, and fibrillation were investigated using two myocardial sheet models: a two-dimensional computer simulation model and a two-dimensional experimental model. A new defibrillation technique that has few side effects, which are induced by the current passing into the patient's body, on cardiac muscle is desired. The purpose of the present study is to conduct a basic investigation into an efficient defibrillation method. In order to evaluate the defibrillation method, the propagation of excitation in the myocardial sheet is measured during the normal state and during fibrillation, respectively. The advantages of the low-energy defibrillation technique are then discussed based on the stimulation timing.

Phonon Self-Energy Corrections to Nonzero Wave-Vector Phonon Modes in Single-Layer Graphene

NASA Astrophysics Data System (ADS)

Araujo, P. T.; Mafra, D. L.; Sato, K.; Saito, R.; Kong, J.; Dresselhaus, M. S.

2012-07-01

Phonon self-energy corrections have mostly been studied theoretically and experimentally for phonon modes with zone-center (q=0) wave vectors. Here, gate-modulated Raman scattering is used to study phonons of a single layer of graphene originating from a double-resonant Raman process with q≠0. The observed phonon renormalization effects are different from what is observed for the zone-center q=0 case. To explain our experimental findings, we explored the phonon self-energy for the phonons with nonzero wave vectors (q≠0) in single-layer graphene in which the frequencies and decay widths are expected to behave oppositely to the behavior observed in the corresponding zone-center q=0 processes. Within this framework, we resolve the identification of the phonon modes contributing to the G⋆ Raman feature at 2450cm-1 to include the iTO+LA combination modes with q≠0 and also the 2iTO overtone modes with q=0, showing both to be associated with wave vectors near the high symmetry point K in the Brillouin zone.

Modulation of Ca2+ Activity in Cardiomyocytes through Caveolae-Gαq Interactions

PubMed Central

Guo, Yuanjian; Golebiewska, Urszula; Scarlata, Suzanne

2011-01-01

Cardiomyocytes have a complex Ca2+ behavior and changes in this behavior may underlie certain disease states. Intracellular Ca2+ activity can be regulated by the phospholipase Cβ–Gαq pathway localized on the plasma membrane. The plasma membranes of cardiomycoytes are rich in caveolae domains organized by caveolin proteins. Caveolae may indirectly affect cell signals by entrapping and localizing specific proteins. Recently, we found that caveolin may specifically interact with activated Gαq, which could affect Ca2+ signals. Here, using fluorescence imaging and correlation techniques we show that Gαq-Gβγ subunits localize to caveolae in adult ventricular canine cardiomyoctyes. Carbachol stimulation releases Gβγ subunits from caveolae with a concurrent stabilization of activated Gαq by caveolin-3 (Cav3). These cells show oscillating Ca2+ waves that are not seen in neonatal cells that do not contain Cav3. Microinjection of a peptide that disrupts Cav3-Gαq association, but not a control peptide, extinguishes the waves. Furthermore, these waves are unchanged with rynaodine treatment, but not seen with treatment of a phospholipase C inhibitor, implying that Cav3-Gαq is responsible for this Ca2+ activity. Taken together, these studies show that caveolae play a direct and active role in regulating basal Ca2+ activity in cardiomyocytes. PMID:21463572

Myocardial dysfunction in mitochondrial diabetes treated with Coenzyme Q10.

PubMed

Salles, João Eduardo; Moisés, Valdir A; Almeida, Dirceu R; Chacra, Antonio R; Moisés, Regina S

2006-04-01

Maternally-inherited diabetes and deafness (MIDD) has been related to an A to G transition in the mitochondrial tRNA Leu (UUR) gene at the base pair 3243. Although some previous articles have reported that this mutation may be a cause of cardiomyopathy in diabetes, the degree of cardiac involvement and a specific treatment has not been established. Here, we reported a case of a patient with MIDD who developed congestive heart failure and the therapeutic usefulness of Coenzyme Q10 (CoQ10). In our patient, after the introduction of Coenzyme Q10 150 mg/day, there was a gradual improvement on left ventricular function evaluated by echocardiography. The fractional shortening (FS) and ejection fraction (EF) increased from 26 to 34% and from 49 to 64%, respectively. No side effects were noted. Three months after CoQ10 discontinuation, the parameters of systolic function evaluated by echocardiography decreased, suggesting that CoQ10 had a beneficial effect. Identification of diabetes and cardiomyopathy due to mitochondrial gene mutation may have therapeutic implications and Coenzyme Q10 is a possible adjunctive treatment in such patients.

Intertwined Orders in Heavy-Fermion Superconductor CeCoIn 5

DOE PAGES

Kim, Duk Young; Lin, Shi-Zeng; Weickert, Franziska; ...

2016-12-20

The appearance of spin-density-wave (SDW) magnetic order in the low-temperature and high-field corner of the superconducting phase diagram of CeCoIn 5 is unique among unconventional superconductors. The nature of this magnetic $Q$ phase is a matter of current debate. Here, we present the thermal conductivity of CeCoIn 5 in a rotating magnetic field, which reveals the presence of an additional order inside the $Q$ phase that is intimately intertwined with the superconducting d-wave and SDW orders. A discontinuous change of the thermal conductivity within the $Q$ phase, when the magnetic field is rotated about antinodes of the superconducting d-wave ordermore » parameter, demands that the additional order must change abruptly, together with the recently observed switching of the SDW. Lastly, a combination of interactions, where spin-orbit coupling orients the SDW, which then selects the secondary p -wave pair-density-wave component (with an average amplitude of 20% of the primary d-wave order parameter), accounts for the observed behavior.« less

Q-values for P and S waves in Southern Sinai and Southern Gulf of Suez Region, Egypt

NASA Astrophysics Data System (ADS)

Mohamed, Gad-Elkareem A.

2014-05-01

The quality factor Q has been estimated using spectral amplitudes of P and S waves from earthquakes recorded by the seismic network of the Egyptian National Seismological Network (ENSN) in southern Sinai and southern Gulf of Suez region. The earthquakes recorded at nine stations - DHA, NUB, TR1, TR2, KAT, SH2, GRB, HRG and SFG have been used in this study. The spectral amplitude ratios have been calculated between 2 - 20 Hz and single station spectral ratio method has been applied for this purpose. The results show that the quality factors for both P and S waves (Qp and Qs) increase as a function of frequency according to law the Q = Q0fn. By averaging the estimated Q- Value obtained at all stations we calculated the average attenuation laws: Qp = (13.15± 0.76) f0.95± 0.19 and Qs = (20.05± 0.79) f1.03±0.04 for P and S waves respectively. These relations are useful for the estimation of source parameters of earthquakes and simulation of earthquake strong ground motions. The QS /QP ratio for KAT station is less than 1 at lower frequencies, whereas at HRG and SH2 stations QS /QP ratio is are greater than 1.

Onset of oscillatory Rayleigh-Bénard magnetoconvection with rigid horizontal boundaries

NASA Astrophysics Data System (ADS)

Mondal, Hiya; Das, Alaka; Kumar, Krishna

2018-01-01

We present the results of linear stability analysis of oscillatory Rayleigh-Bénard magnetoconvection with rigid and thermally conducting boundaries. We have investigated two types of horizontal surfaces: (i) electrically conducting and (ii) boundaries which do not allow any outward current normal to the surface (magnetic vacuum conditions). For the case of electrically conducting boundaries, the critical Rayleigh number R ao(Q ,P r ,P m ) , the critical wave number ko(Q ,P r ,P m ) , and the frequency at the instability onset ω(Q ,P r ,P m ) increase as the Chandrasekhar number Q is raised for fixed non-zero values of thermal Prandtl Pr and magnetic Prandtl number Pm. For small values of Pr, the frequency of oscillation ω at the primary instability shows a rapid increase with Pm for very small values of Pm followed by a decrease at relatively larger values of Pm. In the limit of P r →0 , Rao and ko are found to be independent of Q. However, the frequency ω increases with Q, but decreases with Pm in this limit. The oscillatory instability is possible at the onset of magnetoconvection if and only if Chandrasekhar's criterion is valid (i.e., Pm > Pr) and Q is raised above a critical value Qc(P r ,P m ) such that the product P m *Qc≈91 for large Pm. For the stellar interior of an astrophysical body ( P m ≈10-4 and P r ≈10-8 ), the value of this product P m *Qc≈230 . The boundary conditions for magnetic vacuum change the critical values of Rayleigh number, wave number, and frequency of oscillation at the onset. The oscillatory magnetoconvection occurs in this case, if Q >Qc , where P m *Qc≈42 for large Pm. For steller interior, this value is approximately 64. A low-dimensional model is also constructed to study various patterns near the onset of oscillatory convection for rigid, thermally and electrically conducting boundaries. The model shows standing and drifting fluid patterns in addition to flow reversal close to the onset of magnetoconvection.

S-wave attenuation of the shallow sediments in the North China basin based on borehole seismograms of local earthquakes

NASA Astrophysics Data System (ADS)

Wang, Sheng; Li, Zhiwei

2018-06-01

S-wave velocity and attenuation structures of shallow sediments play important roles in accurate prediction of strong ground motion. However, it is more difficult to investigate the attenuation than velocity structures. In this study, we developed a new approach for estimating frequency-dependent S-wave attenuation (Q_S^{ - 1}) structures of shallow sediments based on multiple time window analysis of borehole seismograms from local earthquakes. Multiple time windows for separating direct and surface-reflected S-waves in local earthquake waveforms at borehole stations are selected with a global optimization scheme. With respect to different time windows, the transfer functions between direct and surface-reflected S-waves are achieved with a weighted averaging scheme, based on which frequency dependent Q_S^{ - 1} values are obtained. Synthetic tests suggest that the proposed method can restore robust and reliableQ_S^{ - 1} values, especially when the dataset of local earthquakes is not abundant. We utilize this method for local earthquake waveforms at 14 borehole seismic stations in the North China basin, and obtain Q_S^{ - 1} values in 2 ˜ 10 Hz frequency band, as well as average {V_P}, {V_S} and {V_P}/{{}}{V_S} ratio for shallow sediments deep to a few hundred meters. Results suggest that Q_S^{ - 1} values are to 0.01˜0.06, and generally decrease with frequency. The average attenuation structure of shallow sediments within the depth of a few hundred meters beneath 14 borehole stations in the North China basin can be modeled as Q_S^{ - 1} = 0.056{f^{ - 0.61}}. It is generally consistent with the attenuation structure of sedimentary basins in other areas, such as Mississippi Embayment sediments in the United States and Sendai basin in Japan.

Inverse scattering in 1-D nonhomogeneous media and recovery of the wave speed

NASA Astrophysics Data System (ADS)

Aktosun, Tuncay; Klaus, Martin; van der Mee, Cornelis

1992-04-01

The inverse scattering problem for the 1-D Schrödinger equation d2ψ/dx2 + k2ψ= k2P(x)ψ + Q(x)ψ is studied. This equation is equivalent to the 1-D wave equation with speed 1/√1-P(x) in a nonhomogeneous medium where Q(x) acts as a restoring force. When Q(x) is integrable with a finite first moment, P(x)<1 and bounded below and satisfies two integrability conditions, P(x) is recovered uniquely when the scattering data and Q(x) are known. Some explicitly solved examples are provided.

Capillary waves' dynamics at the nanoscale

NASA Astrophysics Data System (ADS)

Delgado-Buscalioni, Rafael; Chacón, Enrique; Tarazona, Pedro

2008-12-01

We study the dynamics of thermally excited capillary waves (CW) at molecular scales, using molecular dynamics simulations of simple liquid slabs. The analysis is based on the Fourier modes of the liquid surface, constructed via the intrinsic sampling method (Chacón and Tarazona 2003 Phys. Rev. Lett. 91 166103). We obtain the time autocorrelation of the Fourier modes to get the frequency and damping rate Γd(q) of each mode, with wavenumber q. Continuum hydrodynamics predicts \\Gamma (q) \\propto q\\gamma (q) and thus provides a dynamic measure of the q-dependent surface tension, γd(q). The dynamical estimation is much more robust than the structural prediction based on the amplitude of the Fourier mode, γs(q). Using the optimal estimation of the intrinsic surface, we obtain quantitative agreement between the structural and dynamic pictures. Quite surprisingly, the hydrodynamic prediction for CW remains valid up to wavelengths of about four molecular diameters. Surface tension hydrodynamics break down at shorter scales, whereby a transition to a molecular diffusion regime is observed.

Lateral Variations of Lg Coda Q in Southern Mexico

NASA Astrophysics Data System (ADS)

Yamamoto, J.; Quintanar, L.; Herrmann, R. B.; Fuentes, C.

Broad band digital three-component data recorded at UNM, a GEOSCOPE station, were used to estimate Lg coda Q for 34 medium size (3.9 <=mb<= 6.3) earthquakes with travel paths laying in different geological provinces of southern Mexico in an effort to establish the possible existence of geological structures acting as wave guides and/or travel paths of low attenuation between the Pacific coast and the Valley of Mexico. The stacked spectral ratio method proposed by XIE and NUTTLI (1988) was chosen for computing the coda Q. The variation range of Q0 (Q at 1Hz) and the frequency dependence parameter η estimates averaged on the frequency interval of 0.5 to 2Hz for the regions and the three components considered are: i) Guerrero region 173 <=Q0<= 182 and 0.6 <=Q0<= 0.7, ii) Oaxaca region 183 <=Q0<= 198 and 0.6 <=Q0<= 0.8, iii) Michoacan-Jalisco region 187 <=Q0<= 204 and 0.7 <=Q0<= 0.8 and iv) eastern portion of the Transmexican Volcanic Belt (TMVB) 313 <=Q0<= 335 and η = 0.9. The results show a very high coda Q for the TMVB as compared to other regions of southern Mexico. This unexpected result is difficult to reconcile with the geophysical characteristics of the TMVB, e.g., low seismicity, high volcanic activity and high heat flow typical of a highly attenuating (low Q) region. Visual inspection of seismograms indicates that for earthquakes with seismic waves traveling along the TMVB, the amplitude decay of Lg coda is anomalously slow as compared to other earthquakes in southern Mexico. Thus, it seems that the high Q value found does not entirely reflect the attenuation characteristics of the TMVB but it is probably contaminated by a wave-guide effect. This phenomenon produces an enhancement in the time duration of the Lg wave trains travelling along this geological structure. This result is important to establish the role played by the transmission medium in the extremely long duration of ground motion observed during the September 19, 1985 Michoacan earthquake. The overall spatial distribution of coda Q values indicates that events with focus in the Michoacan-Jalisco and Oaxaca regions yield slightly higher values than those from Guerrero. This feature is more pronounced for the horizontal component of coda Q. A slight dependence of average coda Q-1 on earthquake focal depth is observed in the frequency range of 0.2 to 1.0Hz approximately on the horizontal component. Deeper (h > 50km) events yield lower values of Q-1 than shallower events. For frequencies higher than 1.0Hz no clear dependence of Q-1 on focal depth is observed. However, due to the estimates uncertainties this result is not clearly established.

Compressional Wave Q in the Uppermost Mantle Beneath the Tibetan Plateau Measured Using Pn Wave Spectra

NASA Astrophysics Data System (ADS)

Xie, J.

2003-12-01

Pn waves from three near-colocated seismic events in the eastern Tarim Basin are well-recorded by the INDEPTH III and II arrays, which are deployed from northern to southern Tibet with a small east-west spread (between ˜88 and 91° E). The paths run southward and sample the Tibetan mantle with epicentral distances increasing from 870 to 1540 km. These waves have spectral contents that are distinctly different from those collected from the Kyrghistan network (KNET), to which the paths traverse westward through the eastern Tienshan. Pn Q beneath Tibet and Tienshan must therefore be different. Xie and Patton (1999,JGR, 104, 941-954) have simultaneously estimated source spectra of the co-located events, and path-averaged Pn Q to the KNET stations. Under a simplified geometrical spreading of Δ -1.3, they have estimated Q0 and η (Pn Q at 1 Hz and its frequency dependence) to KNET to be about 360 and 0.5, respectively. Using those estimates as a priori knowledge, we estimate that Q0 and η are ~180 and 0.3 along paths to northern Tibet, and ˜260 and 0.0 along paths to southern Tibet. The southward increase of Q0 correlates well with a similar increase in Pn velocity contained in previous tomographic images. Additionally, we measured Pn Q using a two-station method along two profiles (from station SANG to TUNL, and GANZ to MAQI) deployed during the 1991-1992 Sino-US Tibetan Plateau experiment. Both profiles are located to the east of 92° E. Along profile SANG-TUNL, we estimate Q0 and η to be ˜270 and 0.0, respectively. The Q0 value is rather high, but correlates well with the high Pn velocities of > 8.1 km/s re-measured in this study. Our results suggest that the zone of low Pn Q0 and velocity in northern Tibet, which is likely caused by high mantle temperature and partial melting, is confined to the west of 92° E. This is so despite that the zone of high Sn attenuation extends to further east.

Spatial Variation of Surface Wave Q and Body Wave t* in North America

NASA Astrophysics Data System (ADS)

Hwang, Y.; Ritsema, J.

2007-12-01

We estimate the spatial variation of the seismic parameter t* using teleseismic (30°--90°) P wave recordings of about 300 deep (> 200 km) earthquakes at broadband stations in North America. We determine the P wave spectral ratio Rij for about 600,000 station pairs i-j with high signal-to-noise ratio P wave signals. The linear fit to lnRij between f= 0.1--1.0 Hz is measured to estimate differential Δt* assuming that lnRij is proportional to π fΔt* (e.g., Aki and Richards, 1980). The measurements are inverted for t* at each station by least-squares inversion. Preliminary inversions indicate that the variation of t* correlate with the tectonic terrains of North America. Predominantly low values of t* are obtained for stations in the Canadian Shield and high t* values in the North American Cordillera. This variation is similar to Q variations inferred from global surface wave amplitude data (e.g., Dalton and Ekström, 2006), suggesting that intrinsic attenuation is the common cause. We will discuss the robustness of our t* estimates (including the effects of scattering on P wave ratios) and make a detailed comparison with surface wave Q maps.

Theory of electromagnetic wave propagation in ferromagnetic Rashba conductor

NASA Astrophysics Data System (ADS)

Shibata, Junya; Takeuchi, Akihito; Kohno, Hiroshi; Tatara, Gen

2018-02-01

We present a comprehensive study of various electromagnetic wave propagation phenomena in a ferromagnetic bulk Rashba conductor from the perspective of quantum mechanical transport. In this system, both the space inversion and time reversal symmetries are broken, as characterized by the Rashba field α and magnetization M, respectively. First, we present a general phenomenological analysis of electromagnetic wave propagation in media with broken space inversion and time reversal symmetries based on the dielectric tensor. The dependence of the dielectric tensor on the wave vector q and M is retained to first order. Then, we calculate the microscopic electromagnetic response of the current and spin of conduction electrons subjected to α and M, based on linear response theory and the Green's function method; the results are used to study the system optical properties. First, it is found that a large α enhances the anisotropic properties of the system and enlarges the frequency range in which the electromagnetic waves have hyperbolic dispersion surfaces and exhibit unusual propagations known as negative refraction and backward waves. Second, we consider the electromagnetic cross-correlation effects (direct and inverse Edelstein effects) on the wave propagation. These effects stem from the lack of space inversion symmetry and yield q-linear off-diagonal components in the dielectric tensor. This induces a Rashba-induced birefringence, in which the polarization vector rotates around the vector (α ×q ) . In the presence of M, which breaks time reversal symmetry, there arises an anomalous Hall effect and the dielectric tensor acquires off-diagonal components linear in M. For α ∥M , these components yield the Faraday effect for the Faraday configuration q ∥M and the Cotton-Mouton effect for the Voigt configuration ( q ⊥M ). When α and M are noncollinear, M- and q-induced optical phenomena are possible, which include nonreciprocal directional dichroism in the Voigt configuration. In these nonreciprocal optical phenomena, a "toroidal moment," α ×M , and a "quadrupole moment," αiMj+Miαj , play central roles. These phenomena are strongly enhanced at the spin-split transition edge in the electron band.

Non-conforming finite-element formulation for cardiac electrophysiology: an effective approach to reduce the computation time of heart simulations without compromising accuracy

NASA Astrophysics Data System (ADS)

Hurtado, Daniel E.; Rojas, Guillermo

2018-04-01

Computer simulations constitute a powerful tool for studying the electrical activity of the human heart, but computational effort remains prohibitively high. In order to recover accurate conduction velocities and wavefront shapes, the mesh size in linear element (Q1) formulations cannot exceed 0.1 mm. Here we propose a novel non-conforming finite-element formulation for the non-linear cardiac electrophysiology problem that results in accurate wavefront shapes and lower mesh-dependance in the conduction velocity, while retaining the same number of global degrees of freedom as Q1 formulations. As a result, coarser discretizations of cardiac domains can be employed in simulations without significant loss of accuracy, thus reducing the overall computational effort. We demonstrate the applicability of our formulation in biventricular simulations using a coarse mesh size of ˜ 1 mm, and show that the activation wave pattern closely follows that obtained in fine-mesh simulations at a fraction of the computation time, thus improving the accuracy-efficiency trade-off of cardiac simulations.

Mitochondrial Bioenergetics and Dysfunction in Failing Heart.

PubMed

Sheeran, Freya L; Pepe, Salvatore

2017-01-01

Energy insufficiency has been recognized as a key feature of systolic heart failure. Although mitochondria have long been known to sustain myocardial work energy supply, the capacity to therapeutically target mitochondrial bioenergetics dysfunction is hampered by a complex interplay of multiple perturbations that progressively compound causing myocardial failure and collapse. Compared to non-failing human donor hearts, activity rates of complexes I and IV, nicotinamide nucleotide transhydrogenase (NADPH-transhydrogenase, Nnt) and the Krebs cycle enzymes isocitrate dehydrogenase, malate dehydrogenase and aconitase are markedly decreased in end-stage heart failure. Diminished REDOX capacity with lower total glutathione and coenzyme Q 10 levels are also a feature of chronic left ventricular failure. Decreased enzyme activities in part relate to abundant and highly specific oxidative, nitrosylative, and hyperacetylation modifications. In this brief review we highlight that energy deficiency in end-stage failing human left ventricle predominantly involves concomitantly impaired activities of key electron transport chain and Krebs cycle enzymes rather than altered expression of respective genes or proteins. Augmented oxidative modification of these enzyme subunit structures, and the formation of highly reactive secondary metabolites, implicates dysfunction due to diminished capacity for management of mitochondrial reactive oxygen species, which contribute further to progressive decreases in bioenergetic capacity and contractile function in human heart failure.

[U.S. Food and Drug Administration (FDA) strengthens warning that non-aspirin non steroidal anti-inflammatory drugs (NSAIDs) can cause myocardial infarctions or strokes: the dentist's perspective].

PubMed

Rosen, E; Tsesis, I; Vered, M

2015-10-01

This short communication is aimed to update dental practitioners regarding the recently published warning of the U.S. Food and Drug Administration (FDA) regarding the risk for severe cardiovascular complications such as myocardial infarction or stroke following the use of non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs).

Extracorporeal shock wave therapy for ischemic cardiovascular disorders.

PubMed

Ito, Kenta; Fukumoto, Yoshihiro; Shimokawa, Hiroaki

2011-10-01

Ischemic heart disease is the leading cause of death and a major cause of hospital admissions, with the number of affected patients increasing worldwide. The current management of ischemic heart disease has three major therapeutic options: medication, percutaneous coronary intervention (PCI), and coronary artery bypass grafting (CABG). However, the prognosis for patients with severe ischemic heart disease without indications for PCI or CABG still remains poor due to the lack of effective treatments. It is therefore crucial to develop alternative therapeutic strategies for severe ischemic heart disease. Extracorporeal shock wave (SW) therapy was introduced clinically more than 20 years ago to fragment kidney stones, which has markedly improved the treatment of urolithiasis. We found that a low-energy SW (about 10% of the energy density used for urolithiasis) effectively increases the expression of vascular endothelial growth factor (VEGF) in cultured endothelial cells. Based on this in vitro study, we initiated in vivo studies and have demonstrated that extracorporeal cardiac SW therapy with a low-energy SW up-regulates the expression of VEGF, induces neovascularization, and improves myocardial ischemia in a porcine model of chronic myocardial ischemia, without any adverse effects in vivo. On the basis of promising results in animal studies, we performed a series of clinical studies in patients with severe coronary artery disease without indication for PCI or CABG, including, firstly, an open trial followed by a placebo-controlled, double-blind study. In both studies, our extracorporeal cardiac SW therapy improved symptoms, exercise capacity, and myocardial perfusion in patients with severe coronary artery disease. Importantly, no procedural complications or adverse effects were noted. The SW therapy was also effective in ameliorating left ventricular remodeling after acute myocardial infarction (MI) in pigs and in enhancing angiogenesis in hind-limb ischemia in rabbits. Based on these animal studies, we are also conducting clinical studies in patients with acute MI and in those with peripheral artery disease. Thus, our extracorporeal cardiac SW therapy appears to be an effective, safe, and non-invasive angiogenic approach in cardiovascular medicine and its indication could be extended to a variety of ischemic diseases in the near future. In this article, we briefly summarize our work in animals and humans, and discuss the advantages and perspectives of our extracorporeal SW therapy.

New pulmonary vein Doppler echocardiographic index predicts significant interatrial shunting in secundum atrial septal defect.

PubMed

Lam, Yat-Yin; Fang, Fang; Yip, Gabriel Wai-Kwok; Li, Zhi-An; Yang, Ya; Yu, Cheuk-Man

2012-09-20

The relation between pulmonary venous flow (PVF) pattern and degree of left-to-right interatrial shunting (IAS) in patients with secundum atrial septal defect (ASD) is unknown. Fifty consecutive ASD patients (14 males, 36 ± 17 years) received transthoracic echocardiography (TTE) before and 1 day after transcatheter closure and their results were compared to 40 controls. The ratio of pulmonary-to-systemic flows (Qp/Qs) was assessed by TTE and invasive oximetry. Pre-closure PV systolic (PVs), diastolic (PVd) velocities and velocity-time integral (PV-VTI) increased, time from onset of ECG Q-wave to the peak PV diastolic wave (Q-PVd) shortened and atrial reversal (PVar) velocity significantly decreased as compared to normals. These findings normalized after closure. Patients with large IAS (defined as invasive Qp/Qs ≥ 2) had higher PVs, PVd and PV-VTI, shorter Q-PVd but lower PVar (all p<0.01) than those with small IAS. Invasive Qp/Qs ratios correlated with PVs, PVd, PV-VTI, Q-PVd and TTE-derived Qp/Qs ratios, ASD sizes and RV end-diastolic dimensions (all p<0.05). PV-VTI (β=0.49) and ASD size (β=0.48) remained independent predictors of large IAS after multivariate analysis. The corresponding sensitivity, specificity and AUC were 89%, 82% and 0.90 respectively for a PV-VTI of 30 cm (p<0.001). ASD patients with significant IAS have distinguishable PVF features. Doppler evaluation of PV-VTI is a novel additional tool for assessing the magnitude of shunting in these patients non-invasively. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

C1q Deficiency Promotes Pulmonary Vascular Inflammation and Enhances the Susceptibility of the Lung Endothelium to Injury.

PubMed

Shah, Dilip; Romero, Freddy; Zhu, Ying; Duong, Michelle; Sun, Jianxin; Walsh, Kenneth; Summer, Ross

2015-12-04

The collectin proteins are innate immune molecules found in high concentrations on the epithelial and endothelial surfaces of the lung. While these proteins are known to have important anti-inflammatory actions in the airways of the lung little is known of their functional importance in the pulmonary circulation. We recently demonstrated that the circulating collectin protein adiponectin has potent anti-inflammatory effects on the lung endothelium, leading us to reason that other structurally related proteins might have similar effects. To test this hypothesis, we investigated the anti-inflammatory actions of C1q in lung endothelial homeostasis and the pulmonary vascular response to LPS or HCl injury. We show that lung endothelium from C1q-deficient (C1q(-/-)) mice expresses higher baseline levels of the vascular adhesion markers ICAM-1, VCAM-1, and E-selectin when compared with wild-type mice. Further, we demonstrate that these changes are associated with enhanced susceptibility of the lung to injury as evident by increased expression of adhesion markers, enhanced production of pro-inflammatory cytokines, and augmented neutrophil recruitment. Additionally, we found that C1q(-/-) mice also exhibited enhanced endothelial barrier dysfunction after injury as manifested by decreased expression of junctional adherens proteins and enhanced vascular leakage. Mechanistically, C1q appears to mediate its effects by inhibiting phosphorylation of p38 mitogen-activated protein kinase (MAPK) and blocking nuclear translocation of the P65 subunit of nuclear factor (NF)-κB. In summary, our findings indicate a previously unrecognized role for C1q in pulmonary vascular homeostasis and provide added support for the hypothesis that circulating collectin proteins have protective effects on the lung endothelium. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Identification of novel cytogenetic markers with prognostic significance in a series of 968 patients with primary myelodysplastic syndromes.

PubMed

Solé, Francesc; Luño, Elisa; Sanzo, Carmen; Espinet, Blanca; Sanz, Guillermo F; Cervera, José; Calasanz, María José; Cigudosa, Juan Cruz; Millà, Fuensanta; Ribera, Josep Maria; Bureo, Encarna; Marquez, Maria Luisa; Arranz, Eva; Florensa, Lourdes

2005-09-01

The main prognostic factors in myelodysplastic syndromes (MDS) are chromosomal abnormalities, the proportion of blasts in bone marrow and number and degree of cytopenias. A consensus-defined International Prognostic Scoring System (IPSS) for predicting outcome and planning therapy in MDS has been developed, but its prognostic value in a large and independent series remains unproven. Furthermore, the intermediate-risk cytogenetic subgroup defined by the IPSS includes a miscellaneous number of different single abnormalities of uncertain prognostic significance at present. The main aim of the present study was to identify chromosomal abnormalities with a previously unrecognized good or poor prognosis in order to find new cytogenetic markers with predictive value. We report the cytogenetic findings in a series of 968 patients with primary MDS from the Spanish Cytogenetics Working Group, Grupo Cooperativo Español de Citogenética Hematológica (GCECGH). In this series of 968 MDS patients, we found various cytogenetic aberrations with a new prognostic impact. Complex karyotype, -7/7q- and i(17q) had a poor prognosis; normal karyotype, loss of Y chromosome, deletion 11q, deletion 12p and deletion 20q as single alterations had a good prognosis. Intermediate prognosis aberrations were rearrangements of 3q21q26, trisomy 8, trisomy 9, translocations of 11q and del(17p). Finally, a new group of single or double cytogenetic abnormalities, most of which are considered rare cytogenetic events and are usually included in the intermediate category of the IPSS, showed a trend to poor prognosis. This study suggests that some specific chromosomal abnormalities could be segregated from the IPSS intermediate-risk cytogenetic prognostic subgroup and included in the low risk or in the poor risk groups.

Effect of the architecture of the left ventricle on the speed of the excitation wave in muscle fibers

NASA Astrophysics Data System (ADS)

Nezlobinsky, T. V.; Pravdin, S. F.; Katsnelson, L. B.; Solovyova, O. E.

2016-07-01

It is known that preferential paths for the propagation of an electrical excitation wave in the human ventricular myocardium are associated with muscle fibers in tissue. The speed of the excitation wave along a fiber is several times higher than that across the direction of the fiber. To estimate the effect of the architecture and anisotropy of the myocardium of the left ventricle on the process of its electrical activation, we have studied the relation between the speed of the electrical excitation wave in a one-dimensional isolated myocardial fiber consisting of sequentially coupled cardiomyocytes and in an identical fiber located in the wall of a threedimensional anatomical model of the left ventricle. It has been shown that the speed of a wavefront along the fiber in the three-dimensional myocardial tissue is much higher than that in the one-dimensional fiber. The acceleration of the signal is due to the rotation of directions of fibers in the wall and to the position of the excitation wavefront with respect to the direction of this fiber. The observed phenomenon is caused by the approach of the excitable tissue with rotational anisotropy in its properties to a pseudoisotropic tissue.

Modulated wave formation in myocardial cells under electromagnetic radiation

NASA Astrophysics Data System (ADS)

Takembo, Clovis N.; Mvogo, A.; Ekobena Fouda, H. P.; Kofané, T. C.

2018-06-01

We exclusively analyze the onset and condition of formation of modulated waves in a diffusive FitzHugh-Nagumo model for myocardial cell excitations. The cells are connected through gap junction coupling. An additive magnetic flux variable is used to describe the effect of electromagnetic induction, while electromagnetic radiation is imposed on the magnetic flux variable as a periodic forcing. We used the discrete multiple scale expansion and obtained, from the model equations, a single differential-difference amplitude nonlinear equation. We performed the linear stability analysis of this equation and found that instability features are importantly influenced by the induced electromagnetic gain. We present the unstable and stable regions of modulational instability (MI). The resulting analytic predictions are confirmed by numerical experiments of the generic equations. The results reveal that due to MI, an initial steady state that consisted of a plane wave with low amplitude evolves into a modulated localized wave patterns, soliton-like in shape, with features of synchronization. Furthermore, the formation of periodic pulse train with breathing motion presents a disappearing pattern in the presence of electromagnetic radiation. This could provide guidance and better understanding of sudden heart failure exposed to heavily electromagnetic radiation.

Summation and Cancellation Effects on QRS and ST-Segment Changes Induced by Simultaneous Regional Myocardial Ischemia.

PubMed

Vives-Borrás, Miquel; Jorge, Esther; Amorós-Figueras, Gerard; Millán, Xavier; Arzamendi, Dabit; Cinca, Juan

2018-01-01

Simultaneous ischemia in two myocardial regions is a potentially lethal clinical condition often unrecognized whose corresponding electrocardiographic (ECG) patterns have not yet been characterized. Thus, this study aimed to determine the QRS complex and ST-segment changes induced by concurrent ischemia in different myocardial regions elicited by combined double occlusion of the three main coronary arteries. For this purpose, 12 swine were randomized to combination of 5-min single and double coronary artery occlusion: Group 1: left Circumflex (LCX) and right (RCA) coronary arteries ( n = 4); Group 2: left anterior descending artery (LAD) and LCX ( n = 4) and; Group 3: LAD and RCA ( n = 4). QRS duration and ST-segment displacement were measured in 15-lead ECG. As compared with single occlusion, double LCX+RCA blockade induced significant QRS widening of about 40 ms in nearly all ECG leads and magnification of the ST-segment depression in leads V1-V3 (maximal 228% in lead V3, p < 0.05). In contrast, LAD+LCX or LAD+RCA did not induce significant QRS widening and markedly attenuated the ST-segment elevation in precordial leads (maximal attenuation of 60% in lead V3 in LAD+LCX and 86% in lead V5 in LAD+RCA, p < 0.05). ST-segment elevation in leads V7-V9 was a specific sign of single LCX occlusion. In conclusion, concurrent infero-lateral ischemia was associated with a marked summation effect of the ECG changes previously elicited by each single ischemic region. By contrast, a cancellation effect on ST-segment changes with no QRS widening was observed when the left anterior descending artery was involved.

(p,q) deformations and (p,q)-vector coherent states of the Jaynes-Cummings model in the rotating wave approximation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ben Geloun, Joseph; Govaerts, Jan; Hounkonnou, M. Norbert

2007-03-15

Classes of (p,q) deformations of the Jaynes-Cummings model in the rotating wave approximation are considered. Diagonalization of the Hamiltonian is performed exactly, leading to useful spectral decompositions of a series of relevant operators. The latter include ladder operators acting between adjacent energy eigenstates within two separate infinite discrete towers, except for a singleton state. These ladder operators allow for the construction of (p,q)-deformed vector coherent states. Using (p,q) arithmetics, explicit and exact solutions to the associated moment problem are displayed, providing new classes of coherent states for such models. Finally, in the limit of decoupled spin sectors, our analysis translatesmore » into (p,q) deformations of the supersymmetric harmonic oscillator, such that the two supersymmetric sectors get intertwined through the action of the ladder operators as well as in the associated coherent states.« less

Development of a Guided-Wave Technology Capable of the Detection of Open Cracks and Microcracks in Embedded Trunnion Anchor Rods

DTIC Science & Technology

2014-04-01

piezoelectric material is reported to potentially produce gains up to a factor of 8 over commercially available, high-performance PZT materials...Narrow-band signal (70-200 cycles) Concentrates energy in desired propagation mode and improves response of PZT transducer. High output/sensitivity PZT ...of Mechanical Engineering, Imperial College. Christoph, P., Q-Y Kim, J. Qu, and L. J. Jacobs. 2009. Evaluation of fatigue damage using non-linear

[Non-invasive estimation of aortic flow by local electrical impedance changes].

PubMed

Okuda, N; Ohashi, N; Yamada, M; Fujinami, T

1986-09-01

Aortic flow velocity was measured by catheter-tip flow transducer in 25 patients who underwent left cardiac catheterization for non-invasive estimates by the impedance method. Disk electrodes were attached to the skin at the levels of the second thoracic vertebra in the posterior median line and the V8 lead position for electrocardiography. Alternating current, 350 micro-amperes, 50 KHz constant, was applied to the outer electrode, and impedance changes were detected via the inner electrode. The e wave, or height of the first derivative dz/dt wave of the electrical impedance was lower in cases of old myocardial infarction and higher in cases of aortic valve regurgitation, as compared with the values of the healthy control group. The time lag between the start of the upward deflection and the peak value of the dz/dt wave coincided with that of the aortic flow curve as measured at the aortic arch and descending aorta. These time lags were about 20 to 30 msec as compared with the ascending aortic flow curve, and were -20 to -30 msec as compared with the abdominal aortic flow curve. There was a close correlation between the maximum flow velocity measured at the aortic arch and the height of the e waves. The regression equation was: Y = 0.21X - 1.53, r = 0.88, p less than 0.01. These data suggest that the first derivative of electrical impedance change as obtained by the disk electrode method reflects aortic flow at the arch and descending aorta.

The association between pulse wave velocity and cognitive function: the Sydney Memory and Ageing Study.

PubMed

Singer, Joel; Trollor, Julian N; Crawford, John; O'Rourke, Michael F; Baune, Bernhard T; Brodaty, Henry; Samaras, Katherine; Kochan, Nicole A; Campbell, Lesley; Sachdev, Perminder S; Smith, Evelyn

2013-01-01

Pulse wave velocity (PWV) is a measure of arterial stiffness and its increase with ageing has been associated with damage to cerebral microvessels and cognitive impairment. This study examined the relationship between carotid-femoral PWV and specific domains of cognitive function in a non-demented elderly sample. Data were drawn from the Sydney Memory and Ageing Study, a cohort study of non-demented community-dwelling individuals aged 70-90 years, assessed in successive waves two years apart. In Wave 2, PWV and cognitive function were measured in 319 participants. Linear regression was used to analyse the cross-sectional relationship between arterial stiffness and cognitive function in the whole sample, and separately for men and women. Analysis of covariance was used to assess potential differences in cognition between subjects with PWV measurements in the top and bottom tertiles of the cohort. Covariates were age, education, body mass index, pulse rate, systolic blood pressure, cholesterol, depression, alcohol, smoking, hormone replacement therapy, apolipoprotein E ε4 genotype, use of anti-hypertensive medications, history of stroke, transient ischemic attack, myocardial infarction, angina, diabetes, and also sex for the whole sample analyses. There was no association between PWV and cognition after Bonferroni correction for multiple testing. When examining this association for males and females separately, an association was found in males, with higher PWV being associated with lower global cognition and memory, however, a significant difference between PWV and cognition between males and females was not found. A higher level of PWV was not associated with lower cognitive function in the whole sample.

Relationship of myocardial hibernation, scar, and angiographic collateral flow in ischemic cardiomyopathy with coronary chronic total occlusion.

PubMed

Wang, Li; Lu, Min-Jie; Feng, Lei; Wang, Juan; Fang, Wei; He, Zuo-Xiang; Dou, Ke-Fei; Zhao, Shi-Hua; Yang, Min-Fu

2018-03-07

The relationship between myocardial viability and angiographic collateral flow is not fully elucidated in ischemic cardiomyopathy (ICM) with coronary artery chronic total occlusion (CTO). We aimed to clarify the relationship between myocardial hibernation, myocardial scar, and angiographic collateral flow in these patients. Seventy-one consecutive ICM patients with 122 CTOs and 652 dysfunctional segments within CTO territories were retrospectively analyzed. Myocardial hibernation (perfusion-metabolism mismatch) and the extent of 18 F-fluorodeoxyglucose (FDG) abnormalities were assessed using 99m Tc-sestamibi and 18 F-FDG imaging. Myocardial scar was evaluated by late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging. Collateral flow observed on coronary angiography was assessed using Rentrop classification. In these patients, neither the extent nor frequency of myocardial hibernation or scar was related to the status of collateral flow. Moreover, the matching rate in determining myocardial viability was poor between any 2 imaging indices. The extent of 18 F-FDG abnormalities was linearly related to the extent of LGE rather than myocardial hibernation. Of note, nearly one-third (30.4%) of segments with transmural scar still had hibernating tissue. Hibernation and non-transmural scar had higher sensitivity (63.0% and 66.7%) than collateral flow (37.0%) in predicting global functional improvement. Angiographic collateral cannot accurately predict myocardial viability, and has lower sensitivity in prediction of functional improvement in CTO territories in ICM patients. Hence, assessment of myocardial viability with non-invasive imaging modalities is of importance. Moreover, due to the lack of correlation between myocardial hibernation and scar, these two indices are complementary but not interchangeable.

Absence epilepsy and the CHD2 gene: an adolescent male with moderate intellectual disability, short-lasting psychoses, and an interstitial deletion in 15q26.1–q26.2

PubMed Central

Verhoeven, Willem MA; Egger, Jos IM; Knegt, Alida C; Zuydam, José; Kleefstra, Tjitske

2016-01-01

Deletions of the 15q26 region encompassing the chromodomain helicase DNA binding domain 2 (CHD2) gene have been associated with intellectual disability, behavioral problems, and several types of epilepsy. Including the cases mentioned in ECARUCA (European cytogeneticists association register of unbalanced chromosome aberrations) and DECIPHER (database of genomic variation and phenotype in humans using ensembl resources), so far, a total of 13 intellectually disabled patients with a genetically proven deletion of the CHD2 gene are described, of whom eleven had a history of severe forms of epilepsy starting from a young age. In this article, a moderately intellectually disabled 15-year-old male with a 15q26.1–q26.2 interstitial deletion is reported, who was referred for analysis of two recent short-lasting psychotic episodes that were nonresponsive to antipsychotic treatment and recurrent disinhibited behaviors since early infancy. Careful interdisciplinary assessment revealed that the psychotic phenomena originated from a previously unrecognized absence epilepsy. Treatment with valproic acid was started which resulted in full remission of psychotic symptoms, and consequently, substantial improvement of behavior. It was concluded that in case of (rare) developmental disorders with genetically proven etiology, a detailed inventory of anamnestic data and description of symptomatology over time may elucidate epilepsy-related psychopathology for which a specific treatment regimen is needed. PMID:27274247

Features of Radiation and Propagation of Seismic Waves in the Northern Caucasus: Manifestations in Regional Coda

NASA Astrophysics Data System (ADS)

Kromskii, S. D.; Pavlenko, O. V.; Gabsatarova, I. P.

2018-03-01

Based on the Anapa (ANN) seismic station records of 40 earthquakes ( M W > 3.9) that occurred within 300 km of the station since 2002 up to the present time, the source parameters and quality factor of the Earth's crust ( Q( f)) and upper mantle are estimated for the S-waves in the 1-8 Hz frequency band. The regional coda analysis techniques which allow separating the effects associated with seismic source (source effects) and with the propagation path of seismic waves (path effects) are employed. The Q-factor estimates are obtained in the form Q( f) = 90 × f 0.7 for the epicentral distances r < 120 km and in the form Q( f) = 90 × f1.0 for r > 120 km. The established Q( f) and source parameters are close to the estimates for Central Japan, which is probably due to the similar tectonic structure of the regions. The shapes of the source parameters are found to be independent of the magnitude of the earthquakes in the magnitude range 3.9-5.6; however, the radiation of the high-frequency components ( f > 4-5 Hz) is enhanced with the depth of the source (down to h 60 km). The estimates Q( f) of the quality factor determined from the records by the Sochi, Anapa, and Kislovodsk seismic stations allowed a more accurate determination of the seismic moments and magnitudes of the Caucasian earthquakes. The studies will be continued for obtaining the Q( f) estimates, geometrical spreading functions, and frequency-dependent amplification of seismic waves in the Earth's crust in the other regions of the Northern Caucasus.

CoQ10 and L-carnitine for statin myalgia?

PubMed

DiNicolantonio, James J

2012-10-01

Statins are a standard of care in many clinical settings such as acute myocardial infarction and for patients having or at risk of cardiovascular (CV) disease. This is based on a plethora of data showing reductions in CV events and mortality. The CV benefit of statins can be partly explained by their ability to inhibit of HMG-CoA reductase, which subsequently lowers cholesterol and decreases the formation of mevalonate. However, the inhibition of the mevalonate pathway decreases the formation of coenzyme Q10 (CoQ10) within the body. It has been a long-standing theory that statin-associated muscle pain (myalgia) is caused, or at least partly contributed by, a reduction in CoQ10 levels in muscle mitochondria. One of the main side effects of statins is myalgia, which causes the patient to either stop their statin or significantly reduce the dose of their statin. The question of whether CoQ10 can help treat statin myopathy is a common one encountered by clinicians in current day practice.

Estimation of Coda Wave Attenuation in Northern Morocco

NASA Astrophysics Data System (ADS)

Boulanouar, Abderrahim; Moudnib, Lahcen El; Padhy, Simanchal; Harnafi, Mimoun; Villaseñor, Antonio; Gallart, Josep; Pazos, Antonio; Rahmouni, Abdelaali; Boukalouch, Mohamed; Sebbani, Jamal

2018-03-01

We studied the attenuation of coda waves and its frequency and lapse-time dependence in northern Morocco. We analysed coda waves of 66 earthquakes recorded in this region during 2008 for four lapse time windows of length 30, 40, 50, and 60 s, and at five frequency bands with central frequency in the range of 0.75-12 Hz. We determined the frequency dependent Q c relation for the horizontal (NS and EW) and vertical (Z) component seismograms. We analyzed three-component broadband seismograms of 66 local earthquakes for determining coda-Q based on the single back-scattering model. The Q c values show strong frequency dependence in 1.5-12 Hz that is related to high degree of heterogeneity of the medium. The lapse time dependence of Q c shows that Q 0 ( Q c at 1 Hz) significantly increases with lapse time that is related to the depth dependence of attenuation and hence of the level of heterogeneity of the medium. The average frequency-dependent Q c( f) values are Qc = (143.75 ± 1.09)f^{(0.864 ± 0.006)}, Qc = (149.12 ± 1.08)f^{(0.85 ± 0.005)} and Qc = (140.42 ± 1.81)f^{(0.902 ± 0.004)} for the vertical, north-south and east-west components of motion, respectively. The frequency-dependent Q c(f) relations are useful for evaluating source parameters (Singh et al. 2001), which are the key inputs for seismic hazard assessment of the region.

Pinning, rotation, and metastability of BiFeO 3 cycloidal domains in a magnetic field

DOE PAGES

Fishman, Randy S.

2018-01-03

Earlier models for the room-temperature multiferroic BiFeO 3 implicitly assumed that a very strong anisotropy restricts the domain wave vectors q to the threefold-symmetric axis normal to the static polarization P. However, recent measurements demonstrate that the domain wave vectors q rotate within the hexagonal plane normal to P away from the magnetic field orientation m. In this paper, we show that the previously neglected threefold anisotropy K 3 restricts the wave vectors to lie along the threefold axis in zero field. Taking m to lie along a threefold axis, the domain with q parallel to m remains metastable belowmore » B c1≈7 T. Due to the pinning of domains by nonmagnetic impurities, the wave vectors of the other two domains start to rotate away from m above 5.6 T, when the component of the torque τ=M×B along P exceeds a threshold value τ pin. Since τ=0 when m⊥q, the wave vectors of those domains never become completely perpendicular to the magnetic field. Our results explain recent measurements of the critical field as a function of field orientation, small-angle neutron scattering measurements of the wave vectors, as well as spectroscopic measurements with m along a threefold axis. Finally, the model developed in this paper also explains how the three multiferroic domains of BiFeO 3 for a fixed P can be manipulated by a magnetic field.« less

Pinning, rotation, and metastability of BiFeO3 cycloidal domains in a magnetic field

NASA Astrophysics Data System (ADS)

Fishman, Randy S.

2018-01-01

Earlier models for the room-temperature multiferroic BiFeO3 implicitly assumed that a very strong anisotropy restricts the domain wave vectors q to the threefold-symmetric axis normal to the static polarization P . However, recent measurements demonstrate that the domain wave vectors q rotate within the hexagonal plane normal to P away from the magnetic field orientation m . We show that the previously neglected threefold anisotropy K3 restricts the wave vectors to lie along the threefold axis in zero field. Taking m to lie along a threefold axis, the domain with q parallel to m remains metastable below Bc 1≈7 T. Due to the pinning of domains by nonmagnetic impurities, the wave vectors of the other two domains start to rotate away from m above 5.6 T, when the component of the torque τ =M ×B along P exceeds a threshold value τpin. Since τ =0 when m ⊥q , the wave vectors of those domains never become completely perpendicular to the magnetic field. Our results explain recent measurements of the critical field as a function of field orientation, small-angle neutron scattering measurements of the wave vectors, as well as spectroscopic measurements with m along a threefold axis. The model developed in this paper also explains how the three multiferroic domains of BiFeO3 for a fixed P can be manipulated by a magnetic field.

Pinning, rotation, and metastability of BiFeO 3 cycloidal domains in a magnetic field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fishman, Randy S.

Earlier models for the room-temperature multiferroic BiFeO 3 implicitly assumed that a very strong anisotropy restricts the domain wave vectors q to the threefold-symmetric axis normal to the static polarization P. However, recent measurements demonstrate that the domain wave vectors q rotate within the hexagonal plane normal to P away from the magnetic field orientation m. In this paper, we show that the previously neglected threefold anisotropy K 3 restricts the wave vectors to lie along the threefold axis in zero field. Taking m to lie along a threefold axis, the domain with q parallel to m remains metastable belowmore » B c1≈7 T. Due to the pinning of domains by nonmagnetic impurities, the wave vectors of the other two domains start to rotate away from m above 5.6 T, when the component of the torque τ=M×B along P exceeds a threshold value τ pin. Since τ=0 when m⊥q, the wave vectors of those domains never become completely perpendicular to the magnetic field. Our results explain recent measurements of the critical field as a function of field orientation, small-angle neutron scattering measurements of the wave vectors, as well as spectroscopic measurements with m along a threefold axis. Finally, the model developed in this paper also explains how the three multiferroic domains of BiFeO 3 for a fixed P can be manipulated by a magnetic field.« less

Determining arterial wave transit time from a single aortic pressure pulse in rats: vascular impulse response analysis.

PubMed

Chang, Ru-Wen; Chang, Chun-Yi; Lai, Liang-Chuan; Wu, Ming-Shiou; Young, Tai-Horng; Chen, Yih-Sharng; Wang, Chih-Hsien; Chang, Kuo-Chu

2017-01-19

Arterial wave transit time (τ w ) in the lower body circulation is an effective biomarker of cardiovascular risk that substantially affects systolic workload imposed on the heart. This study evaluated a method for determining τ w from the vascular impulse response on the basis of the measured aortic pressure and an assumed triangular flow (Q tri ). The base of the unknown Q tri was constructed with a duration set equal to ejection time. The timing of the peak triangle was derived using a fourth-order derivative of the pressure waveform. Values of τ w s obtained using Q tri were compared with those obtained from the measure aortic flow wave (Q m ). Healthy rats (n = 27), rats with chronic kidney disease (CKD; n = 22), and rats with type 1 (n = 22) or type 2 (n = 11) diabetes were analyzed. The cardiovascular conditions in the CKD rats and both diabetic groups were characterized by a decrease in τ w s. The following significant relation was observed (P < 0.0001): τ w triQ  = -1.5709 + 1.0604 × τ w mQ (r 2  = 0.9641). Our finding indicates that aortic impulse response can be an effective method for the estimation of arterial τ w by using a single pressure recording together with the assumed Q tri .

Ultrasound imaging of propagation of myocardial contraction for non-invasive identification of myocardial ischemia

NASA Astrophysics Data System (ADS)

Matsuno, Yuya; Taki, Hirofumi; Yamamoto, Hiroaki; Hirano, Michinori; Morosawa, Susumu; Shimokawa, Hiroaki; Kanai, Hiroshi

2017-07-01

Non-invasive identification of ischemic regions is important for diagnosis and treatment of myocardial infarction. In the present study, ultrasound measurement was applied to the interventricular septum of three open-chest swine hearts. The properties of the myocardial contraction response of the septum were compared between normal and acute ischemic conditions, where the acute ischemic condition of the septum originated from direct avascularization of the left anterior descending (LAD) coronary artery. The result showed that the contraction response propagated from the basal side to the apical side along the septum. The estimated propagation velocities in the normal and acute ischemic conditions were 3.6 and 1.9 m/s, respectively. This finding indicates that acute ischemia which occurred 5 s after the avascularization of the LAD promptly suppressed the propagation velocity through the ventricular septum to about half the normal velocity. It was suggested that the myocardial ischemic region could be identified using the difference in the propagation velocity of the myocardial response to contraction.

Novel cardiovascular magnetic resonance oxygenation approaches in understanding pathophysiology of cardiac diseases.

PubMed

Sree Raman, Karthigesh; Nucifora, Gaetano; Selvanayagam, Joseph B

2018-05-01

Cardiovascular magnetic resonance imaging (CMR) permits accurate phenotyping of many cardiac diseases. CMR's inherent advantages are its non-invasive nature, lack of ionizing radiation and high accuracy and reproducibility. Furthermore, it is able to assess many aspects of cardiac anatomy, structure and function. Specifically, it can characterize myocardial tissue, myocardial function, myocardial mass, myocardial blood flow/perfusion, irreversible and reversible injury, all with a high degree of accuracy and reproducibility. Hence, CMR is a powerful tool in clinical and pre-clinical research. In recent years there have been novel advances in CMR myocardial tissue characterization. Oxygenation-sensitive CMR (OS-CMR) is a novel non-invasive, contrast independent technique that permits direct quantification of myocardial tissue oxygenation, both at rest and during stress. In this review, we will address the principles of the OS-CMR technique, its recent advances and summarize the studies in the effects of oxygenation on cardiac diseases. © 2018 John Wiley & Sons Australia, Ltd.

Comparison of the effects of candesartan cilexetil and enalapril maleate on right ventricular myocardial remodeling in dogs with experimentally induced pulmonary stenosis.

PubMed

Yamane, Tsuyoshi; Fujii, Yoko; Orito, Kensuke; Osamura, Kaori; Kanai, Takao; Wakao, Yoshito

2008-12-01

To compare the effects of candesartan cilexetil and enalapril maleate on right ventricular myocardial remodeling in dogs with experimentally induced pulmonary stenosis. 24 Beagles. 18 dogs underwent pulmonary arterial banding (PAB) to induce right ventricular pressure overload, and 6 healthy dogs underwent sham operations (thoracotomy only [sham-operated group]). Dogs that underwent PAB were allocated to receive 1 of 3 treatments (6 dogs/group): candesartan (1 mg/kg, PO, q 24 h [PABC group]), enalapril (0.5 mg/kg, PO, q 24 h [PABE group]), or no treatment (PABNT group). Administration of treatments was commenced the day prior to surgery; control dogs received no cardiac medications. Sixty days after surgery, right ventricular wall thickness was assessed echocardiographically and plasma renin activity, angiotensin-converting enzyme activity, and angiotensin I and II concentrations were assessed; all dogs were euthanatized, and collagenous fiber area, cardiomyocyte diameter, and tissue angiotensin-converting enzyme and chymase-like activities in the right ventricle were evaluated. After 60 days of treatment, right ventricular wall thickness, cardiomyocyte diameter, and collagenous fiber area in the PABNT and PABE groups were significantly increased, compared with values in the PABC and sham-operated groups. Chymase-like activity was markedly greater in the PABE group than in other groups. Results indicated that treatment with candesartan but not enalapril effectively prevented myocardial remodeling in dogs with experimentally induced subacute right ventricular pressure overload.

Regional Body-Wave Attenuation Using a Coda Source Normalization Method: Application to MEDNET Records of Earthquakes in Italy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walter, W R; Mayeda, K; Malagnini, L

2007-02-01

We develop a new methodology to determine apparent attenuation for the regional seismic phases Pn, Pg, Sn, and Lg using coda-derived source spectra. The local-to-regional coda methodology (Mayeda, 1993; Mayeda and Walter, 1996; Mayeda et al., 2003) is a very stable way to obtain source spectra from sparse networks using as few as one station, even if direct waves are clipped. We develop a two-step process to isolate the frequency-dependent Q. First, we correct the observed direct wave amplitudes for an assumed geometrical spreading. Next, an apparent Q, combining path and site attenuation, is determined from the difference between themore » spreading-corrected amplitude and the independently determined source spectra derived from the coda methodology. We apply the technique to 50 earthquakes with magnitudes greater than 4.0 in central Italy as recorded by MEDNET broadband stations around the Mediterranean at local-to-regional distances. This is an ideal test region due to its high attenuation, complex propagation, and availability of many moderate sized earthquakes. We find that a power law attenuation of the form Q(f) = Q{sub 0}f{sup Y} fit all the phases quite well over the 0.5 to 8 Hz band. At most stations, the measured apparent Q values are quite repeatable from event to event. Finding the attenuation function in this manner guarantees a close match between inferred source spectra from direct waves and coda techniques. This is important if coda and direct wave amplitudes are to produce consistent seismic results.« less

Propagation of symmetric and anti-symmetric surface waves in aself-gravitating magnetized dusty plasma layer with generalized (r, q) distribution

NASA Astrophysics Data System (ADS)

Lee, Myoung-Jae; Jung, Young-Dae

2018-05-01

The dispersion properties of surface dust ion-acoustic waves in a self-gravitating magnetized dusty plasma layer with the (r, q) distribution are investigated. The result shows that the wave frequency of the symmetric mode in the plasma layer decreases with an increase in the wave number. It is also shown that the wave frequency of the symmetric mode decreases with an increase in the spectral index r. However, the wave frequency of the anti-symmetric mode increases with an increase in the wave number. It is also found that the anti-symmetric mode wave frequency increases with an increase in the spectral index r. In addition, it is found that the influence of the self-gravitation on the symmetric mode wave frequency decreases with increasing scaled Jeans frequency. Moreover, it is found that the wave frequency of the symmetric mode increases with an increase in the dust charge; however, the anti-symmetric mode shows opposite behavior.

Association of the genetic markers for myocardial infarction with sudden cardiac death.

PubMed

Ivanova, Anastasiya A; Maksimov, Vladimir N; Orlov, Pavel S; Ivanoshchuk, Dinara E; Savchenko, Sergei V; Voevoda, Mikhail I

2017-04-01

Investigate the association of rs17465637 gene MIAF3 (1q41), rs1376251 gene TAS2R50 (12p13), rs4804611 gene ZNF627 (19p13), rs619203 gene ROS1 (6q22), rs1333049 (9p21), rs10757278 (9p21), rs2549513 (16q23), rs499818 (6p24) associated with myocardial infarction available from the international genome-wide studies with sudden cardiac death (SCD) in a case-control study. A sample of SCD cases (n=285) was formed using the WHO criteria; the control sample (n=421) was selected according to sex and age. DNA was isolated by phenol-chloroform extraction from the myocardial tissue of SCD cases and blood of control cases. The groups were genotyped for the selected SNPs by real-time PCR using TaqMan probes (Applied Biosystems, United States). No statistically significant differences in the genotype and allelic frequencies of studied single nucleotide polymorphisms between sudden cardiac death cases and control were detectable in general group. By separating the groups of sex and age differences in the genotype frequencies of rs1333049, rs10757278 and rs499818 are statistical significance. Genotypes CC of rs1333049 and GG of rs10757278 are associated with an increased sudden cardiac death risk in men (p=0.019, OR=1.7, 95% CI 1.1-2.8; p=0.011, OR=1.8, 95% CI 1.2-2.8, respectively). Genotype AG of rs499818 is associated with an increased sudden cardiac death risk in the women over 50 years old (p=0.009, OR=2.4, 95% CI 1.3-4.6). Polymorphisms rs1333049 and rs10757278 are associated with SCD in men and rs499818 in the women aged over 50 years. Copyright © 2016. Published by Elsevier B.V.

Ultrasound backscatter tensor imaging (BTI): analysis of the spatial coherence of ultrasonic speckle in anisotropic soft tissues.

PubMed

Papadacci, Clement; Tanter, Mickael; Pernot, Mathieu; Fink, Mathias

2014-06-01

The assessment of fiber architecture is of major interest in the progression of myocardial disease. Recent techniques such as magnetic resonance diffusion tensor imaging (MR-DTI) or ultrasound elastic tensor imaging (ETI) can derive the fiber directions by measuring the anisotropy of water diffusion or tissue elasticity, but these techniques present severe limitations in a clinical setting. In this study, we propose a new technique, backscatter tensor imaging (BTI), which enables determination of the fiber directions in skeletal muscles and myocardial tissues, by measuring the spatial coherence of ultrasonic speckle. We compare the results to ultrasound ETI. Acquisitions were performed using a linear transducer array connected to an ultrasonic scanner mounted on a motorized rotation device with angles from 0° to 355° by 5° increments to image ex vivo bovine skeletal muscle and porcine left ventricular myocardial samples. At each angle, multiple plane waves were transmitted and the backscattered echoes recorded. The coherence factor was measured as the ratio of coherent intensity over incoherent intensity of backscattered echoes. In skeletal muscle, maximal/minimal coherence factor was found for the probe parallel/perpendicular to the fibers. In myocardium, the coherence was assessed across the entire myocardial thickness, and the position of maxima and minima varied transmurally because of the complex fibers distribution. In ETI, the shear wave speed variation with the probe angle was found to follow the coherence variation. Spatial coherence can thus reveal the anisotropy of the ultrasonic speckle in skeletal muscle and myocardium. BTI could be used on any type of ultrasonic scanner with rotating phased-array probes or 2-D matrix probes for noninvasive evaluation of myocardial fibers.

Twin photon pairs in a high-Q silicon microresonator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rogers, Steven; Lu, Xiyuan; Jiang, Wei C.

2015-07-27

We report the generation of high-purity twin photon pairs through cavity-enhanced non-degenerate four-wave mixing (FWM) in a high-Q silicon microdisk resonator. Twin photon pairs are created within the same cavity mode and are consequently expected to be identical in all degrees of freedom. The device is able to produce twin photons at telecommunication wavelengths with a pair generation rate as large as (3.96 ± 0.03) × 10{sup 5} pairs/s, within a narrow bandwidth of 0.72 GHz. A coincidence-to-accidental ratio of 660 ± 62 was measured, the highest value reported to date for twin photon pairs, at a pair generation rate of (2.47 ±more » 0.04) × 10{sup 4} pairs/s. Through careful engineering of the dispersion matching window, we have reduced the ratio of photons resulting from degenerate FWM to non-degenerate FWM to less than 0.15.« less

Prevention of coronary atherosclerosis by the use of combination therapy with antioxidant coenzyme Q10 and statins.

PubMed

Chapidze, G; Kapanadze, S; Dolidze, N; Bachutashvili, Z; Latsabidze, N

2005-01-01

The goal of the present research was to assess the efficacy of combination treatment with antioxidant coenzyme Q10 and simvastatin as well as coenzyme Q10 without statin therapy in order to prevent coronary atherosclerosis. 42 outpatients were divided into 2 groups: receiving coenzyme Q10 (Hasco-Lek, Poland) 60mg daily and its combination with simvastatin (zocor, vasilip) 10mg daily for an 8-week period. The treatment with coenzyme Q10 demonstrated its potential independent role in positive modification of oxidative stress, antiatherogenic fraction of lipid profile, atherogenic ratio, platelet aggregability. Taking into consideration the obtained results the study supports the use of coenzyme Q10 in combination with statins. Suggested attractive approach may result in complete correction of dislipidemia, reverse of endothelial dysfunction, reduce degree of oxidative stress and platelet aggregability. Consequently such a combination may be beneficial in preventing of further development of atherosclerosis in native coronary arteries as well as in bypass grafts in all coronary heart disease patients with or without myocardial revascularization.

Thrombus Aspiration in ThrOmbus containing culpRiT lesions in Non-ST-Elevation Myocardial Infarction (TATORT-NSTEMI): study protocol for a randomized controlled trial

PubMed Central

2013-01-01

Background Current guidelines recommend thrombus aspiration in patients with ST-elevation myocardial infarction (STEMI); however, there are insufficient data to unequivocally support thrombectomy in patients with non-STEMI (NSTEMI). Methods/Design The TATORT-NSTEMI (Thrombus Aspiration in ThrOmbus containing culpRiT lesions in Non-ST-Elevation Myocardial Infarction) trial is a prospective, controlled, multicenter, randomized, open-label trial enrolling 460 patients. The hypothesis is that, against a background of early revascularization, adjunctive thrombectomy leads to less microvascular obstruction (MO) compared with conventional percutaneous coronary intervention (PCI) alone, as assessed by cardiac magnetic resonance imaging (CMR) in patients with NSTEMI. Patients will be randomized in a 1:1 fashion to one of the two treatment arms. The primary endpoint is the extent of late MO assessed by CMR. Secondary endpoints include early MO, infarct size, and myocardial salvage assessed by CMR as well as enzymatic infarct size and angiographic parameters, such as thrombolysis in myocardial infarction flow post-PCI and myocardial blush grade. Furthermore, clinical endpoints including death, myocardial re-infarction, target vessel revascularization, and new congestive heart failure will be recorded at 6 and 12 months. Safety will be assessed by the incidence of bleeding and stroke. Summary The TATORT-NSTEMI trial has been designed to test the hypothesis that thrombectomy will improve myocardial perfusion in patients with NSTEMI and relevant thrombus burden in the culprit vessel reperfused by early PCI. Trial registration The trial is registered under http://www.clinicaltrials.gov: NCT01612312. PMID:23782681

T-wave area as biomarker of clinical response to cardiac resynchronization therapy.

PubMed

Végh, Eszter M; Engels, Elien B; van Deursen, Caroline J M; Merkely, Béla; Vernooy, Kevin; Singh, Jagmeet P; Prinzen, Frits W

2016-07-01

There is increasing evidence that left bundle branch block (LBBB) morphology on the electrocardiogram is a positive predictor for response to cardiac resynchronization therapy (CRT). We previously demonstrated that the vectorcardiography (VCG)-derived T-wave area predicts echocardiographic CRT response in LBBB patients. In the present study, we investigate whether the T-wave area also predicts long-term clinical outcome to CRT. This is a retrospective study consisting of 335 CRT recipients. Primary endpoint were the composite of heart failure (HF) hospitalization, heart transplantation, left ventricular assist device implantation or death during a 3-year follow-up period. HF hospitalization and death alone were secondary endpoints. The patient subgroup with a large T-wave area and LBBB 36% reached the primary endpoint, which was considerably less (P < 0.01) than for patients with LBBB and a small T-wave area or non-LBBB patients with a small or large T-wave area (48, 57, and 51%, respectively). Similar differences were observed for the secondary endpoints, HF hospitalization (31 vs. 51, 51, and 38%, respectively, P < 0.01) and death (19 vs. 42, 34, and 42%, respectively, P < 0.01). In multivariate analysis, a large T-wave area and LBBB were the only independent predictors of the combined endpoint besides high creatinine levels and use of diuretics. T-wave area may be useful as an additional biomarker to stratify CRT candidates and improve selection of those most likely to benefit from CRT. A large T-wave area may derive its predictive value from reflecting good intrinsic myocardial properties and a substrate for CRT. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Universal relations for spin-orbit-coupled Fermi gas near an s -wave resonance

NASA Astrophysics Data System (ADS)

Zhang, Pengfei; Sun, Ning

2018-04-01

Synthetic spin-orbit-coupled quantum gases have been widely studied both experimentally and theoretically in the past decade. As shown in previous studies, this modification of single-body dispersion will in general couple different partial waves of the two-body scattering and thus distort the wave function of few-body bound states which determines the short-distance behavior of many-body wave function. In this work, we focus on the two-component Fermi gas with one-dimensional or three-dimensional spin-orbit coupling (SOC) near an s -wave resonance. Using the method of effective field theory and the operator product expansion, we derive universal relations for both systems, including the adiabatic theorem, viral theorem, and pressure relation, and obtain the momentum distribution matrix 〈ψa†(q ) ψb(q ) 〉 at large q (a ,b are spin indices). The momentum distribution matrix shows both spin-dependent and spatial anisotropic features. And the large momentum tail is modified at the subleading order thanks to the SOC. We also discuss the experimental implication of these results depending on the realization of the SOC.

Germ line insertion of mtDNA at the breakpoint junction of a reciprocal constitutional translocation.

PubMed

Willett-Brozick, J E; Savul, S A; Richey, L E; Baysal, B E

2001-08-01

Constitutional chromosomal translocations are relatively common causes of human morbidity, yet the DNA double-strand break (DSB) repair mechanisms that generate them are incompletely understood. We cloned, sequenced and analyzed the breakpoint junctions of a familial constitutional reciprocal translocation t(9;11)(p24;q23). Within the 10-kb region flanking the breakpoints, chromosome 11 had 25% repeat elements, whereas chromosome 9 had 98% repeats, 95% of which were L1-type LINE elements. The breakpoints occurred within an L1-type repeat element at 9p24 and at the 3'-end of an Alu sequence at 11q23. At the breakpoint junction of derivative chromosome 9, we discovered an unusually large 41-bp insertion, which showed 100% identity to 12S mitochondrial DNA (mtDNA) between nucleotides 896 and 936 of the mtDNA sequence. Analysis of the human genome failed to show the preexistence of the inserted sequence at normal chromosomes 9 and 11 breakpoint junctions or elsewhere in the genome, strongly suggesting that the insertion was derived from human mtDNA and captured into the junction during the DSB repair process. To our knowledge, these findings represent the first observation of spontaneous germ line insertion of modern human mtDNA sequences and suggest that DSB repair may play a role in inter-organellar gene transfer in vivo. Our findings also provide evidence for a previously unrecognized insertional mechanism in human, by which non-mobile extra-chromosomal fragments can be inserted into the genome at DSB repair junctions.

Diode-pumped continuous wave and passively Q-switched Tm, Mg: LiTaO₃ lasers.

PubMed

Feng, T; Li, T; Zhao, S; Li, Q; Yang, K; Zhao, J; Qiao, W; Hang, Y; Zhang, P; Wang, Y; Xu, J

2014-02-24

We have demonstrated the continuous wave and passively Q-switched Tm, Mg: LiTaO3 lasers for the first time. In continuous wave (CW) regime, a maximum CW output power of 1.03 W at 1952 nm was obtained, giving a slope efficiency of 9.5% and a beam quality M2 = 2.2. In passive Q-switching regime, a single walled carbon nanotube (SWCNT) was employed as saturable absorber (SA). The Tm,Mg:LiTaO3 laser has yielded a pulse of 560 ns under repetition rate of 34.2 kHz at 1926 nm, corresponding to a single pulse energy of 10.1 μJ. The results indicate a promising potential of nonlinear crystals in the applications for laser host materials.

Non-ventricular, Clinical, and Functional Features of the RyR2(R420Q) Mutation Causing Catecholaminergic Polymorphic Ventricular Tachycardia.

PubMed

Domingo, Diana; Neco, Patricia; Fernández-Pons, Elena; Zissimopoulos, Spyros; Molina, Pilar; Olagüe, José; Suárez-Mier, M Paz; Lai, F Anthony; Gómez, Ana M; Zorio, Esther

2015-05-01

Catecholaminergic polymorphic ventricular tachycardia is a malignant disease, due to mutations in proteins controlling Ca(2+) homeostasis. While the phenotype is characterized by polymorphic ventricular arrhythmias under stress, supraventricular arrhythmias may occur and are not fully characterized. Twenty-five relatives from a Spanish family with several sudden deaths were evaluated with electrocardiogram, exercise testing, and optional epinephrine challenge. Selective RyR2 sequencing in an affected individual and cascade screening in the rest of the family was offered. The RyR2(R420Q) mutation was generated in HEK-293 cells using site-directed mutagenesis to conduct in vitro functional studies. The exercise testing unmasked catecholaminergic polymorphic ventricular tachycardia in 8 relatives (sensitivity = 89%; positive predictive value = 100%; negative predictive value = 93%), all of them carrying the heterozygous RyR2(R420Q) mutation, which was also present in the proband and a young girl without exercise testing, a 91% penetrance at the end of the follow-up. Remarkably, sinus bradycardia, atrial and junctional arrhythmias, and/or giant post-effort U-waves were identified in patients. Upon permeabilization and in intact cells, the RyR2(R420Q) expressing cells showed a smaller peak of Ca(2+) release than RyR2 wild-type cells. However, at physiologic intracellular Ca(2+) concentration, equivalent to the diastolic cytosolic concentration, the RyR2(R420Q) released more Ca(2+) and oscillated faster than RyR2 wild-type cells. The missense RyR2(R420Q) mutation was identified in the N-terminus of the RyR2 gene in this highly symptomatic family. Remarkably, this mutation is associated with sinus bradycardia, atrial and junctional arrhythmias, and giant U-waves. Collectively, functional heterologous expression studies suggest that the RyR2(R420Q) behaves as an aberrant channel, as a loss- or gain-of-function mutation depending on cytosolic intracellular Ca(2+) concentration. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Inflammatory response, neutrophil activation, and free radical production after acute myocardial infarction: effect of thrombolytic treatment.

PubMed Central

Bell, D; Jackson, M; Nicoll, J J; Millar, A; Dawes, J; Muir, A L

1990-01-01

Activated neutrophils releasing proteolytic enzymes and oxygen free radicals have been implicated in extending myocardial injury after myocardial infarction. Neutrophil elastase was used as a marker of neutrophil activation and the non-peroxide diene conjugate of linoleic acid was used as an indicator of free radical activity in 32 patients after acute myocardial infarction; 17 were treated by intravenous thrombolysis. Patients with acute myocardial infarction had higher plasma concentrations of neutrophil elastase and the non-peroxide diene conjugated isomer of linoleic acid than normal volunteers or patients with stable ischaemic heart disease. Patients treated by thrombolysis had an early peak of neutrophil elastase at eight hours while those who had not been treated by thrombolysis showed a later peak 40 hours after infarction. The plasma concentration of non-peroxide conjugated diene of linoleic acid was highest 16 hours after the infarction irrespective of treatment by thrombolysis. Quantitative imaging with single photon emission tomography showed decreased uptake of indium-111 labelled neutrophils in the infarcted myocardium (as judged from technetium-99m pyrophosphate) in those who had received thrombolysis, suggesting a decreased inflammatory response. The results indicate increased neutrophil activation and free radical production after myocardial infarction; they also suggest that thrombolysis does not amplify the inflammatory response and may indeed suppress it. Images PMID:2317413

System and method for phase retrieval for radio telescope and antenna control

NASA Technical Reports Server (NTRS)

Dean, Bruce H. (Inventor)

2013-01-01

Disclosed herein are systems, methods, and non-transitory computer-readable storage media for radio phase retrieval. A system practicing the method gathers first data from radio waves associated with an object observed via a first aperture, gathers second data from radio waves associated with the object observed via an introduced second aperture associated with the first aperture, generates reduced noise data by incoherently subtracting the second data from the first data, and performs phase retrieval for the radio waves by modeling the reduced noise data using a single Fourier transform. The first and second apertures are at different positions, such as side by side. This approach can include determining a value Q which represents a ratio of wavelength times a focal ratio divided by pixel spacing. This information can be used to accurately measure and correct alignment errors or other optical system flaws in the apertures.

Optimism and hope as predictors of subjective health in post-myocardial infarction patients: A comparison of the role of coping strategies.

PubMed

Wlodarczyk, Dorota

2017-03-01

This study explored the effects intervening in the linkages of optimism and hope with subjective health in the short term after myocardial infarction. A two-wave study design was used. The sample consisted of 222 myocardial infarction survivors. When adopting a cross-sectional design, optimism and hope predicted subjective health at Time 1 and Time 2. After controlling for baseline subjective health, they were no longer significant predictors of subjective health at Time 2. Parallel indirect effects of seeking social support and problem solving were significant for both optimism and hope. After controlling for the shared variance between optimism and hope, these effects remained significant only for optimism.

Measuring Age-Dependent Myocardial Stiffness across the Cardiac Cycle using MR Elastography: A Reproducibility Study

PubMed Central

Wassenaar, Peter A; Eleswarpu, Chethanya N; Schroeder, Samuel A; Mo, Xiaokui; Raterman, Brian D; White, Richard D; Kolipaka, Arunark

2015-01-01

Purpose To assess reproducibility in measuring left ventricular (LV) myocardial stiffness in volunteers throughout the cardiac cycle using magnetic resonance elastography (MRE) and to determine its correlation with age. Methods Cardiac MRE (CMRE) was performed on 29 normal volunteers, with ages ranging from 21 to 73 years. For assessing reproducibility of CMRE-derived stiffness measurements, scans were repeated per volunteer. Wave images were acquired throughout the LV myocardium, and were analyzed to obtain mean stiffness during the cardiac cycle. CMRE-derived stiffness values were correlated to age. Results Concordance correlation coefficient revealed good inter-scan agreement with rc of 0.77, with p-value<0.0001. Significantly higher myocardial stiffness was observed during end-systole (ES) compared to end-diastole (ED) across all subjects. Additionally, increased deviation between ES and ED stiffness was observed with increased age. Conclusion CMRE-derived stiffness is reproducible, with myocardial stiffness changing cyclically across the cardiac cycle. Stiffness is significantly higher during ES compared to ED. With age, ES myocardial stiffness increases more than ED, giving rise to an increased deviation between the two. PMID:26010456

P and S wave attenuation tomography of the Japan subduction zone

NASA Astrophysics Data System (ADS)

Wang, Zewei; Zhao, Dapeng; Liu, Xin; Chen, Chuanxu; Li, Xibing

2017-04-01

We determine the first high-resolution P and S wave attenuation (Q) tomography beneath the entire Japan Islands using a large number of high-quality t∗ data collected from P and S wave velocity spectra of 4222 local shallow and intermediate-depth earthquakes. The suboceanic earthquakes used in this study are relocated precisely using sP depth phases. Significant landward dipping high-Q zones are revealed clearly, which reflect the subducting Pacific slab beneath Hokkaido and Tohoku, and the subducting Philippine Sea (PHS) slab beneath SW Japan. Prominent low-Q zones are visible in the crust and mantle wedge beneath the active arc volcanoes in Hokkaido, Tohoku, and Kyushu, which reflect source zones of arc magmatism caused by fluids from the slab dehydration and corner flow in the mantle wedge. Our results also show that nonvolcanic low-frequency earthquakes (LFEs) in SW Japan mainly occur in the transition zone between a narrow low-Q belt and its adjacent high-Q zones right above the flat segment of the PHS slab. This feature suggests that the nonvolcanic LFEs are caused by not only fluid-affected slab interface but also specific conditions such as high pore pressure which is influenced by the overriding plate.

Magnetic Ordering of Erbium and Uranium NICKEL(2) SILICON(2) by Neutron Scattering

NASA Astrophysics Data System (ADS)

Lin, Hong

The magnetic ordering has been studied in UNi _2Si_2 and erbium single crystals by elastic neutron scattering. Abundant results are given regarding the magnetic structure, magnetic phase transitions, and the effect of a magnetic field on these properties. Three ordered phases are observed in UNi _2Si_2. They have been determined to be an incommensurate longitudinal spin density wave with a magnetic wave vector around q = 0.74c ^* in the high temperature phase, a simple body-centred antiferromagnet in the intermediate temperature phase, and a square wave in the low temperature phase. This square wave can be viewed equivalently as a longitudinal spin density wave with q = 2/3c ^* superimposed on a ferromagnetic component. Hysteresis and sample dependence are observed in the low-temperature phase transition. The two lower temperature phase transitions are both first order. The transition to paramagnetism is second order with a critical exponent beta = 0.35 +/- 0.03. When a magnetic field is applied along the c axis, the intermediate temperature phase is destabilised and disappears above a field of 3.5T. Although there is no new phase induced by the field, there exists a reentrant point where the three ordered phases can coexist. Erbium has three distinct ordered phases: the cone phase at low temperatures, the c-axis modulated (CAM) phase at higher temperatures, and the intermediate phase with moments modulated both along c and perpendicular to c. Within these phases the modulation of the moments may lock in to the lattice. The observed weak harmonics of the wave vector q in the basal plane for the cone phase and the q = 1/4c^* structure in the intermediate phase can be explained by a basal-plane spin slip model. The effect of magnetic field along the c axis on the magnetic structure is to stabilise the cone phase and to destabilise the intermediate phase. A new lock-in structure with q = 1/4c^* in the cone phase is induced by fields above 1.8T. The presence of the field also stabilises the lock-in structure with q = 2/7c^* in both the intermediate and the CAM phases.

Resonantly diode-pumped continuous-wave and Q-switched Er:YAG laser at 1645 nm.

PubMed

Chang, N W H; Simakov, N; Hosken, D J; Munch, J; Ottaway, D J; Veitch, P J

2010-06-21

We describe an efficient Er:YAG laser that is resonantly pumped using continuous-wave (CW) laser diodes at 1470 nm. For CW lasing, it emits 6.1 W at 1645 nm with a slope efficiency of 36%, the highest efficiency reported for an Er:YAG laser that is pumped in this manner. In Q-switched operation, the laser produces diffraction-limited pulses with an average power of 2.5 W at 2 kHz PRF. To our knowledge this is the first Q-switched Er:YAG laser resonantly pumped by CW laser diodes.

Diode-pumped continuous-wave and passively Q-switched Nd:GdLuAG laser at 1443.9 nm

NASA Astrophysics Data System (ADS)

Wu, Qianwen; Liu, Zhaojun; Zhang, Sasa; Cong, Zhenghua; Guan, Chen; Xue, Feng; Chen, Hui; Huang, Qingjie; Xu, Xiaodong; Xu, Jun; Qin, Zengguang

2017-12-01

We investigated the 1443.9 nm laser characteristics of Nd:GdLuAG crystal. Diode-end-pumping configuration was employed under both continuous-wave (CW) and passively Q-switched operations. For CW operation, the maximum average output power was 1.36 W with a slope efficiency of 15%. By using a V3+:YAG crystal as the saturable absorber, we obtained the maximum average output power of 164 mW under Q-switched operation. The corresponding pulse energy was 29.3 μJ and pulse duration was 59 ns.

Left ventricular myocardial velocities and deformation indexes in top-level athletes.

PubMed

D'Andrea, Antonello; Cocchia, Rosangela; Riegler, Lucia; Scarafile, Raffaella; Salerno, Gemma; Gravino, Rita; Golia, Enrica; Pezzullo, Enrica; Citro, Rodolfo; Limongelli, Giuseppe; Pacileo, Giuseppe; Cuomo, Sergio; Caso, Pio; Russo, Maria Giovanna; Bossone, Eduardo; Calabrò, Raffaele

2010-12-01

The aim of this study was to define the range of left ventricular (LV) velocities and deformation indexes in highly trained athletes, analyzing potential differences induced by different long-term training protocols. Standard echocardiography, pulsed-wave tissue Doppler echocardiography, and two-dimensional strain echocardiography of the interventricular septum and lateral wall were performed in 370 endurance athletes and 280 power athletes. Using pulsed-wave tissue Doppler, the following parameters of myocardial function were assessed: systolic peak velocities (S(m)), early (E(m)) and late (A(m)) diastolic velocities, and the E(m)/A(m) ratio. By two-dimensional strain echocardiography, peaks of regional systolic strain and LV global longitudinal strain were calculated. LV mass index and ejection fraction did not significantly differ between the two groups. However, power athletes showed an increased sum of wall thicknesses (P < .01) and relative wall thickness, while LV stroke volume and LV end-diastolic diameter (P < .001) were greater in endurance athletes. By pulsed-wave tissue Doppler analysis, E(m) and E(m)/A(m) at both the septal and lateral wall levels were higher in endurance athletes. By two-dimensional strain echocardiography, myocardial deformation indexes were comparable between the two groups. E(m)/A(m) ratios ≥ 1 were found in the overall population, while 90 % of athletes had an E(m) ≥ 16 cm/sec, S(m) ≥ 10 cm/sec, and global longitudinal strain ≤ -16%. Multivariate analyses evidenced independent positive association between Em peak velocity and LV end-diastolic volume (P < .001) and an independent correlation of global longitudinal strain with the sum of LV wall thicknesses (P < .005). This study describes the full spectrum of systolic and diastolic myocardial velocities and deformation indexes in a large population of competitive athletes. Copyright © 2010 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.

Transthoracic Cardiac Acoustic Radiation Force Impulse Imaging

NASA Astrophysics Data System (ADS)

Bradway, David Pierson

This dissertation investigates the feasibility of a real-time transthoracic Acoustic Radiation Force Impulse (ARFI) imaging system to measure myocardial function non-invasively in clinical setting. Heart failure is an important cardiovascular disease and contributes to the leading cause of death for developed countries. Patients exhibiting heart failure with a low left ventricular ejection fraction (LVEF) can often be identified by clinicians, but patients with preserved LVEF might be undetected if they do not exhibit other signs and symptoms of heart failure. These cases motivate development of transthoracic ARFI imaging to aid the early diagnosis of the structural and functional heart abnormalities leading to heart failure. M-Mode ARFI imaging utilizes ultrasonic radiation force to displace tissue several micrometers in the direction of wave propagation. Conventional ultrasound tracks the response of the tissue to the force. This measurement is repeated rapidly at a location through the cardiac cycle, measuring timing and relative changes in myocardial stiffness. ARFI imaging was previously shown capable of measuring myocardial properties and function via invasive open-chest and intracardiac approaches. The prototype imaging system described in this dissertation is capable of rapid acquisition, processing, and display of ARFI images and shear wave elasticity imaging (SWEI) movies. Also presented is a rigorous safety analysis, including finite element method (FEM) simulations of tissue heating, hydrophone intensity and mechanical index (MI) measurements, and thermocouple transducer face heating measurements. For the pulse sequences used in later animal and clinical studies, results from the safety analysis indicates that transthoracic ARFI imaging can be safely applied at rates and levels realizable on the prototype ARFI imaging system. Preliminary data are presented from in vivo trials studying changes in myocardial stiffness occurring under normal and abnormal heart function. Presented is the first use of transthoracic ARFI imaging in a serial study of heart failure in a porcine model. Results demonstrate the ability of transthoracic ARFI to image cyclically-varying stiffness changes in healthy and infarcted myocardium under good B-mode imaging conditions at depths in the range of 3-5 cm. Challenging imaging scenarios such as deep regions of interest, vigorous lateral motion and stable, reverberant clutter are analyzed and discussed. Results are then presented from the first study of clinical feasibility of transthoracic cardiac ARFI imaging. At the Duke University Medical Center, healthy volunteers and patients having magnetic resonance imaging-confirmed apical infarcts were enrolled for the study. The number of patients who met the inclusion criteria in this preliminary clinical trial was low, but results showed that the limitations seen in animal studies were not overcome by allowing transmit power levels to exceed the FDA mechanical index (MI) limit. The results suggested the primary source of image degradation was clutter rather than lack of radiation force. Additionally, the transthoracic method applied in its present form was not shown capable of tracking propagating ARFI-induced shear waves in the myocardium. Under current instrumentation and processing methods, results of these studies support feasibility for transthoracic ARFI in high-quality B-Mode imaging conditions. Transthoracic ARFI was not shown sensitive to infarct or to tracking heart failure in the presence of clutter and signal decorrelation. This work does provide evidence that transthoracic ARFI imaging is a safe non-invasive tool, but clinical efficacy as a diagnostic tool will need to be addressed by further development to overcome current challenges and increase robustness to sources of image degradation.

Addressing the link between paraoxonase-1 gene variants and the incidence of early onset myocardial infarction

PubMed Central

Hashad, Ingy M.; Abou-Aisha, Khaled; Abdel-Maksoud, Sahar M.; Gad, Mohamed Z.

2015-01-01

Introduction The enzyme paraoxonase-1 (PON1) represents an endogenous defense mechanism against vascular oxidative stress, thereby contributing to the prevention of atherosclerosis. Several polymorphisms have been reported in the PON1 gene, including Q192R. PON1 phenotype is commonly expressed as the paraoxonase/arylesterase ratio (PON/ARE). The major aim of this study was to investigate the association between PON1 Q192R polymorphism, PON1 phenotypes and the incidence of early-onset acute myocardial infarction (AMI) in Egyptians. Material and methods The study subjects consisted of 102 AMI patients and 72 age-matched healthy controls. Genotyping and enzyme activities were determined using PCR-RFLP and kinetic spectrophotometric assays, respectively. Results The genotype distribution for the PON1 gene was significantly different between AMI patients (QQ = 38.24%, QR = 49.02%, RR = 12.75%) and controls (QQ = 66.67%, QR = 25%, RR = 8.33%). Allele frequencies were also significantly different between patients (Q = 62.75%, R = 37.25%) and controls (Q = 79.17%, R = 20.83%). The genotypes QR and RR showed higher risk for AMI compared to the homozygous QQ (odds ratio (OR) = 3.231, p < 0.001). The average PON/ARE ratio in MI patients (1.187 ±0.1) did not differ significantly from controls (1.118 ±0.26). However, it showed a significant difference among different genotypes in both AMI patients (QQ = 0.91 ±0.11, QR = 1.09 ±0.11 and RR = 2.65 ±0.4) (p = 0.0002) and controls (QQ = 0.68 ±0.1, QR = 1.07 ±0.11 and RR = 4.89 ±2.84) (p < 0.0001). Conclusions PON1 192R allele represents an independent risk factor for early-onset AMI in Egyptians, and PON1 Q192R polymorphism modulates the paraoxonase phenotype. PMID:26170843

The continual innovation of commercial PET/CT solutions in nuclear cardiology: Siemens Healthineers.

PubMed

Bendriem, Bernard; Reed, Jessie; McCullough, Kathryn; Khan, Mohammad Raza; Smith, Anne M; Thomas, Damita; Long, Misty

2018-04-10

Cardiac PET/CT is an evolving, non-invasive imaging modality that impacts patient management in many clinical scenarios. Beyond offering the capability to assess myocardial perfusion, inflammatory cardiac pathologies, and myocardial viability, cardiac PET/CT also allows for the non-invasive quantitative assessment of myocardial blood flow (MBF) and myocardial flow reserve (MFR). Recognizing the need for an enhanced comprehension of coronary physiology, Siemens Healthineers implemented a sophisticated solution for the calculation of MBF and MFR in 2009. As a result, each aspect of their innovative scanner and image-processing technology seamlessly integrates into an efficient, easy-to-use workflow for everyday clinical use that maximizes the number of patients who potentially benefit from this imaging modality.

Endothelial function is associated with myocardial diastolic function in women with systemic lupus erythematosus.

PubMed

Chin, Calvin W L; Chin, Chee-Yang; Ng, Marie X R; Le, Thu-Thao; Huang, Fei-Qiong; Fong, Kok-Yong; Thumboo, Julian; Tan, Ru-San

2014-09-01

Endothelial dysfunction is associated with traditional and systemic lupus erythematosus (SLE)-specific risk factors, and early data suggest reversibility of endothelial dysfunction with therapy. The clinical relevance of endothelial function assessment has been limited by the lack of studies, demonstrating its prognostic significance and impact on early myocardial function. Therefore, we aimed to determine the association between endothelial and myocardial diastolic function in SLE women. Women with SLE and no coronary artery disease were prospectively recruited and underwent radionuclide myocardial perfusion imaging (MPI) (Jetstream, Philips, the Netherlands) to exclude subclinical myocardial ischemia. Cardiac and vascular functions were assessed in all patients (Alpha 10, Aloka, Tokyo). Diastolic function was assessed using pulse wave early (E) and late mitral blood inflow and myocardial tissue Doppler (mean of medial and lateral annulus e') velocities. Endothelial function was measured using brachial artery flow-mediated vasodilatation (FMD%). Univariate and multivariate linear regressions were used to assess the association between FMD% and myocardial diastolic function, adjusting for potential confounders. Thirty-eight patients without detectable myocardial ischemia on MPI were studied (mean age 44 ± 10 years; mean disease duration 14 ± 6 years). About 61 % of patients had normal diastolic function (E/e' ≤ 8), and 5 % of patients had definite diastolic dysfunction with E/e' > 13 (mean 7.1 ± 2.9). FMD% was associated with E/e' (regression coefficient β = -0.35; 95 % CI -0.62 to -0.08; p = 0.01) independent of systolic blood pressure, age, and SLICC/ACR Damage Index.

Comparison of baseline characteristics and one-year outcomes between African-Americans and Caucasians undergoing percutaneous coronary intervention.

PubMed

Leborgne, Laurent; Cheneau, Edouard; Wolfram, Roswitha; Pinnow, Ellen E; Canos, Daniel A; Pichard, Augusto D; Suddath, William O; Satler, Lowell F; Lindsay, Joseph; Waksman, Ron

2004-02-15

The objectives of this study were to determine whether there are race-based differences in baseline characteristics and in short- or long-term outcomes after percutaneous coronary intervention (PCI). African-Americans have a higher incidence of coronary artery disease but are less likely to undergo coronary revascularization than Caucasians. Little is known about the profiles and outcomes of African-Americans who undergo PCI. Consecutive series of 1,268 African-Americans and 10,561 Caucasians with symptomatic coronary artery disease who underwent PCI between January 1994 and June 2001 were analyzed. Patients hospitalized for acute myocardial infarction were excluded. African-Americans were older, were more likely to be women, and had more co-morbid baseline conditions compared with Caucasians. Preprocedure lesion characteristics were similar with regard to vessel size, length, and complexity. The rate of clinical success did not differ between the groups. African-Americans experienced more in-hospital combined events of death and Q-wave myocardial infarction (p = 0.03). After propensity score adjustment, African-American race was not an independent predictor for in-hospital events. At 1 year, African-Americans had a slightly lower rate of target lesion revascularization and a 50% higher rate of death (9.8% vs. 6.4%, p <0.001), with a relative risk of 1.52 (95% confidence interval 1.22 to 1.89). In multivariate analysis, African-American race remained a significant predictor of increased 1-year mortality (hazard ratio 1.35, 95% confidence interval 1.06 to 1.71, p = 0.01). African-Americans undergoing angioplasty have more co-morbid baseline conditions than Caucasians. Despite similar clinical success, 1-year outcomes are impaired in African-Americans.

99Tcm-MIBI single photon emission tomography (SPET) for detecting myocardial ischaemia and necrosis in patients with significant coronary artery disease.

PubMed

Sciammarella, M G; Fragasso, G; Gerundini, P; Maffioli, L; Cappelletti, A; Margonato, A; Savi, A; Chierchia, S

1992-12-01

The ability of 99Tcm-methoxyisobutylisonitrile (MIBI) single photon emission tomography (SPET) to detect myocardial ischaemia and necrosis was assessed in 56 patients (45 male, 11 female, aged 55 +/- 5 years), with clinically recognized ischaemic heart disease (IHD). All underwent coronary angiography (CA) and left ventriculography (LV). SPET images were obtained at rest and at peak exercise (Modified Bruce) 90 min after injection of 99Tcm-MIBI (650-850 MBq). Data were acquired in 30 min over 180 degrees (from 45 degrees RAO to 45 degrees LPO) with no correction for attenuation, using a 64 x 64 matrix. The presence of persistent (P) or reversible (R) perfusion defects (PD) was then correlated to the resting and exercise ECG and to the results of CA and LV. Of the 56 patients, 34 had reversible underperfusion (RPD), 46 persistent underperfusion (PPD) and 31 had both. The occurrence of RPD correlated well with the occurrence of exercise-induced ST segment depression and/or angina (27 patients of 34 patients, 79%) and with the presence of significant coronary artery disease (CAD) (33 of 44, 73%). In 45 of 46 patients (98%) PPD corresponded to akinetic or severely hypokinetic segments (LV) usually explored by ECG leads exhibiting diagnostic Q waves (42 of 46 patients, 91%). The scan was normal both at rest and after stress in four of 11 patients with no CAD, and in two of 45 patients with CAD. Finally, an abnormal resting scan was seen in seven of 11 patients with normal coronary arteries, of whom six had regional wall motion abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary surgery and coronary angioplasty in patients with two-vessel coronary artery disease.

PubMed

Weintraub, W S; King, S B; Jones, E L; Douglas, J S; Craver, J M; Liberman, H A; Morris, D C; Guyton, R A

1993-03-01

There is uncertainty regarding the selection between coronary artery surgery and angioplasty in many patients with coronary artery disease, especially in those with 2-vessel disease. Whereas randomized trials will provide the best possible and most detailed data comparing therapy in these patients, clinical data bases may be used to provide a current perspective. The purpose of this study was to compare the long-term outcome of patients with 2-vessel coronary artery disease undergoing coronary surgery or angioplasty at Emory University hospitals in the years 1984 and 1985. Data on all patients with 2-vessel disease diagnosed at Emory University who underwent elective angioplasty or coronary surgery in the years 1984 and 1985 were compared. Categoric variables were analyzed by chi-square and continuous variables by unpaired t test. Survival was determined by the Kaplan-Meier method and differences in survival by the Mantel-Cox method. Determinants of survival were determined by Cox model analysis. There were 415 angioplasty patients and 454 surgical patients. Surgical patients were older and had more frequent systemic hypertension, diabetes mellitus, prior myocardial infarction, severe angina and congestive failure, and more significant narrowing in the left anterior descending coronary artery, totally occluded vessels and left ventricular dysfunction than did angioplasty patients. Complete revascularization was achieved more often in surgical patients. There was no difference in Q-wave myocardial infarction in the hospital. No angioplasty patient died compared with 1.1% of surgical patients (p = 0.03). Whereas 5-year survival was 93% in angioplasty patients and 89% in surgical patients (p = 0.11), there was no difference in risk-adjusted survival.(ABSTRACT TRUNCATED AT 250 WORDS)

An in silico framework to analyze the anisotropic shear wave mechanics in cardiac shear wave elastography

NASA Astrophysics Data System (ADS)

Caenen, Annette; Pernot, Mathieu; Peirlinck, Mathias; Mertens, Luc; Swillens, Abigail; Segers, Patrick

2018-04-01

Shear wave elastography (SWE) is a potential tool to non-invasively assess cardiac muscle stiffness. This study focused on the effect of the orthotropic material properties and mechanical loading on the performance of cardiac SWE, as it is known that these factors contribute to complex 3D anisotropic shear wave propagation. To investigate the specific impact of these complexities, we constructed a finite element model with an orthotropic material law subjected to different uniaxial stretches to simulate SWE in the stressed cardiac wall. Group and phase speed were analyzed in function of tissue thickness and virtual probe rotation angle. Tissue stretching increased the group and phase speed of the simulated shear wave, especially in the direction of the muscle fiber. As the model provided access to the true fiber orientation and material properties, we assessed the accuracy of two fiber orientation extraction methods based on SWE. We found a higher accuracy (but lower robustness) when extracting fiber orientations based on the location of maximal shear wave speed instead of the angle of the major axis of the ellipsoidal group speed surface. Both methods had a comparable performance for the center region of the cardiac wall, and performed less well towards the edges. Lastly, we also assessed the (theoretical) impact of pathology on shear wave physics and characterization in the model. It was found that SWE was able to detect changes in fiber orientation and material characteristics, potentially associated with cardiac pathologies such as myocardial fibrosis. Furthermore, the model showed clearly altered shear wave patterns for the fibrotic myocardium compared to the healthy myocardium, which forms an initial but promising outcome of this modeling study.

Functional Testing Underlying Coronary Revascularisation

ClinicalTrials.gov

2016-10-04

Multivessel Coronary Artery Disease; Vessel Disease; Stable Angina; Unstable Angina or Stabilized Non-ST Elevated Myocardial Infarction; Patients With ST-elevated Myocardial Infarction; Revascularization of Culprit Coronary Artery

Multi-Band (K- Q- and E-Band) Multi-Tone Millimeter-Wave Frequency Synthesizer for Radio Wave Propagation Studies

NASA Technical Reports Server (NTRS)

Simons, Rainee N.; Wintucky, Edwin G.

2014-01-01

This paper presents the design and test results of a multi-band multi-tone millimeter-wave frequency synthesizer, based on a solid-state frequency comb generator. The intended application of the synthesizer is in a space-borne transmitter for radio wave atmospheric studies at K-band (18 to 26.5 GHz), Q-band (37 to 42 GHz), and E-band (71 to 76 GHz). These studies would enable the design of robust multi-Gbps data rate space-to-ground satellite communication links. Lastly, the architecture for a compact multi-tone beacon transmitter, which includes a high frequency synthesizer, a polarizer, and a conical horn antenna, has been investigated for a notional CubeSat based space-to-ground radio wave propagation experiment.

Major influence of a 'smoke and mirrors' effect caused by wave reflection on early diastolic coronary arterial wave intensity.

PubMed

Mynard, Jonathan P; Penny, Daniel J; Smolich, Joseph J

2018-03-15

Coronary wave intensity analysis (WIA) is an emerging technique for assessing upstream and downstream influences on myocardial perfusion. It is thought that a dominant backward decompression wave (BDW dia ) is generated by a distal suction effect, while early-diastolic forward decompression (FDW dia ) and compression (FCW dia ) waves originate in the aorta. We show that wave reflection also makes a substantial contribution to FDW dia , FCW dia and BDW dia , as quantified by a novel method. In 18 sheep, wave reflection accounted for ∼70% of BDW dia , whereas distal suction dominated in a computer model representing a hypertensive human. Non-linear addition/subtraction of mechanistically distinct waves (e.g. wave reflection and distal suction) obfuscates the true contribution of upstream and downstream forces on measured waves (the 'smoke and mirrors' effect). The mechanisms underlying coronary WIA are more complex than previously thought and the impact of wave reflection should be considered when interpreting clinical and experimental data. Coronary arterial wave intensity analysis (WIA) is thought to provide clear insight into upstream and downstream forces on coronary flow, with a large early-diastolic surge in coronary flow accompanied by a prominent backward decompression wave (BDW dia ), as well as a forward decompression wave (FDW dia ) and forward compression wave (FCW dia ). The BDW dia is believed to arise from distal suction due to release of extravascular compression by relaxing myocardium, while FDW dia and FCW dia are thought to be transmitted from the aorta into the coronary arteries. Based on an established multi-scale computational model and high-fidelity measurements from the proximal circumflex artery (Cx) of 18 anaesthetized sheep, we present evidence that wave reflection has a major impact on each of these three waves, with a non-linear addition/subtraction of reflected waves obscuring the true influence of upstream and downstream forces through concealment and exaggeration, i.e. a 'smoke and mirrors' effect. We also describe methods, requiring additional measurement of aortic WIA, for unravelling the separate influences of wave reflection versus active upstream/downstream forces on coronary waves. Distal wave reflection accounted for ∼70% of the BDW dia in sheep, but had a lesser influence (∼25%) in the computer model representing a hypertensive human. Negative reflection of the BDW dia at the coronary-aortic junction attenuated the Cx FDW dia (by ∼40% in sheep) and augmented Cx FCW dia (∼5-fold), relative to the corresponding aortic waves. We conclude that wave reflection has a major influence on early-diastolic WIA, and thus needs to be considered when interpreting coronary WIA profiles. © 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society.

Quasi-Elastic Neutron Scattering Studies of the Slow Dynamics of Supercooled and Glassy Aspirin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yang; Tyagi, M.; Mamontov, Eugene

Aspirin, also known as acetylsalicylic acid (ASA), is not only a wonderful drug, but also a good glass former. Therefore, it serves as an important molecular system to study the near-arrest and arrested phenomena. In this paper, a high-resolution quasi-elastic neutron scattering (QENS) technique is used to investigate the slow dynamics of supercooled liquid and glassy aspirin from 410 K down to 350 K. The measured QENS spectra can be analyzed with a stretched exponential model. We find that (i) the stretched exponent (Q) is independent of the wave vector transfer Q in the measured Q-range, and (ii) the structuralmore » relaxation time (Q) follows a power law dependence on Q. Consequently, the Q-independent structural relaxation time 0 can be extracted for each temperature to characterize the slow dynamics of aspirin. The temperature dependence of 0 can be fitted with the mode coupling power law, the Vogel-Fulcher-Tammann equation and a universal equation for fragile glass forming liquids recently proposed by M. Tokuyama in the measured temperature range. The calculated dynamic response function T(Q,t) using the experimentally determined self-intermediate scattering function of the hydrogen atoms of aspirin shows a direct evidence of the enhanced dynamic fluctuations as the aspirin is increasingly supercooled, in agreement with the fixed-time mean squared displacement x2 and non-Gaussian parameter 2 extracted from the elastic scattering.« less

GPCR-autoantibodies in chronic heart failure.

PubMed

Boivin-Jahns, Valerie; Jahns, Roland

2018-06-01

Chronic heart failure (CHF) is a syndrome characterized by shortness of breath, fluid retention, and a progressive reduction in cardiac function. More than 60% of the cases are ischemic in origin (i.e., due to myo-cardial infarction) and about 30% are caused by non-ischemic myocardial damage (i.e., due to genetic or non-genetic causes like myocardial inflammation). Because of alterations in both cellular and humoral immunity patients with non-ischemic CHF often develop abnormal or misled immune responses, including cross-reacting antibodies and/or autoantibodies to various cardiac anti-gens. Non-ischemic myo-cardial damage was found to progress to CHF particularly, when associated (a) with the generation of autoantibodies directed against distinct myocyte membrane proteins critically involved in cardiac function - like G-protein coup-led membrane receptors (GPCRs), or (b) with virus persistence in the myocardium. This article will review current knowledge on the pathophysiological relevance of GPCR-autoreactivity in CHF by giving an overview on the so far available evidence from pre-clinical, clinical and epidemiological studies on the CHF-inducing potential of GPCR-autoantibodies and thereon based novel therapeutic approaches in GPCR autoantibody-associated CHF.

Frequency dependent Lg attenuation in south-central Alaska

USGS Publications Warehouse

McNamara, D.E.

2000-01-01

The characteristics of seismic energy attenuation are determined using high frequency Lg waves from 27 crustal earthquakes, in south-central Alaska. Lg time-domain amplitudes are measured in five pass-bands and inverted to determine a frequency-dependent quality factor, Q(f), model for south-central Alaska. The inversion in this study yields the frequency-dependent quality factor, in the form of a power law: Q(f) = Q0fη = 220(±30) f0.66(±0.09) (0.75≤f≤12Hz). The results from this study are remarkably consistent with frequency dependent quality factor estimates, using local S-wave coda, in south-central Alaska. The consistency between S-coda Q(f) and Lg Q(f) enables constraints to be placed on the mechanism of crustal attenuation in south-central Alaska. For the range of frequencies considered in this study both scattering and intrinsic attenuation mechanisms likely play an equal role.

Quantum Bohmian model for financial market

NASA Astrophysics Data System (ADS)

Choustova, Olga Al.

2007-01-01

We apply methods of quantum mechanics for mathematical modeling of price dynamics at the financial market. The Hamiltonian formalism on the price/price-change phase space describes the classical-like evolution of prices. This classical dynamics of prices is determined by “hard” conditions (natural resources, industrial production, services and so on). These conditions are mathematically described by the classical financial potential V(q), where q=(q1,…,qn) is the vector of prices of various shares. But the information exchange and market psychology play important (and sometimes determining) role in price dynamics. We propose to describe such behavioral financial factors by using the pilot wave (Bohmian) model of quantum mechanics. The theory of financial behavioral waves takes into account the market psychology. The real trajectories of prices are determined (through the financial analogue of the second Newton law) by two financial potentials: classical-like V(q) (“hard” market conditions) and quantum-like U(q) (behavioral market conditions).

[Comparison of Quantification of Myocardial Infarct Size by One Breath Hold Single Shot PSIR Sequence and Segmented FLASH-PSIR Sequence at 3. 0 Tesla MR].

PubMed

Cheng, Wei; Cai, Shu; Sun, Jia-yu; Xia, Chun-chao; Li, Zhen-lin; Chen, Yu-cheng; Zhong, Yao-zu

2015-05-01

To compare the two sequences [single shot true-FISP-PSIR (single shot-PSIR) and segmented-turbo-FLASH-PSIR (segmented-PSIR)] in the value of quantification for myocardial infarct size at 3. 0 tesla MRI. 38 patients with clinical confirmed myocardial infarction were served a comprehensive gadonilium cardiac MRI at 3. 0 tesla MRI system (Trio, Siemens). Myocardial delayed enhancement (MDE) were performed by single shot-PSIR and segmented-PSIR sequences separatedly in 12-20 min followed gadopentetate dimeglumine injection (0. 15 mmol/kg). The quality of MDE images were analysed by experienced physicians. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) between the two techniques were compared. Myocardial infarct size was quantified by a dedicated software automatically (Q-mass, Medis). All objectives were scanned on the 3. 0T MR successfully. No significant difference was found in SNR and CNR of the image quality between the two sequences (P>0. 05), as well as the total myocardial volume, between two sequences (P>0. 05). Furthermore, there were still no difference in the infarct size [single shot-PSIR (30. 87 ± 15. 72) mL, segmented-PSIR (29. 26±14. 07) ml], ratio [single shot-PSIR (22. 94%±10. 94%), segmented-PSIR (20. 75% ± 8. 78%)] between the two sequences (P>0. 05). However, the average aquisition time of single shot-PSIR (21. 4 s) was less than that of the latter (380 s). Single shot-PSIR is equal to segmented-PSIR in detecting the myocardial infarct size with less acquisition time, which is valuable in the clinic application and further research.

Pharmacological postconditioning with atorvastatin calcium attenuates myocardial ischemia/reperfusion injury in diabetic rats by phosphorylating GSK3β.

PubMed

Chen, Linyan; Cai, Ping; Cheng, Zhendong; Zhang, Zaibao; Fang, Jun

2017-07-01

Diabetes is an independent risk factor for myocardial ischemia, and many epidemiological data and laboratory studies have revealed that diabetes significantly exacerbated myocardial ischemia/reperfusion injury and ameliorated protective effects. The present study aimed to determine whether pharmacological postconditioning with atorvastatin calcium lessened diabetic myocardial ischemia/reperfusion injury, and investigated the role of glycogen synthase kinase (GSK3β) in this. A total of 72 streptozotocin-induced diabetic rats were randomly divided into six groups, and 24 age-matched male non-diabetic Sprague-Dawley rats were randomly divided into two groups. Rats all received 40 min myocardial ischemia followed by 180 min reperfusion, except sham-operated groups. Compared with the non-diabetic ischemia/reperfusion model group, the diabetic ischemia/reperfusion group had a comparable myocardial infarct size, but a higher level of serum cardiac troponin I (cTnI) and morphological alterations to their myocardial cells. Compared with the diabetic ischemia/reperfusion group, the group that received pharmacological postconditioning with atorvastatin calcium had smaller myocardial infarct sizes, lower levels of cTnI, reduced morphological alterations to myocardial cells, higher levels of p-GSK3β, heat shock factor (HSF)-1 and heat shock protein (HSP)70. The cardioprotective effect conferred by atorvastatin calcium did not attenuate myocardial ischemia/reperfusion injury following application of TDZD-8, which phosphorylates and inactivates GSK3β. Pharmacological postconditioning with atorvastatin calcium may attenuate diabetic heart ischemia/reperfusion injury in the current context. The phosphorylation of GSK3β serves a critical role during the cardioprotection in diabetic rats, and p-GSK3β may accelerate HSP70 production partially by activating HSF-1 during myocardial ischemic/reperfusion injury.

Effect of socioeconomic group on incidence of, management of, and survival after myocardial infarction and coronary death: analysis of community coronary event register.

PubMed Central

Morrison, C.; Woodward, M.; Leslie, W.; Tunstall-Pedoe, H.

1997-01-01

OBJECTIVE: To investigate the effect of socioeconomic group (with reference to age and sex) on the rate of, course of, and survival after coronary events. DESIGN: Community coronary event register from 1985 to 1991. SETTING: City of Glasgow north of the River Clyde, population 196,000. SUBJECTS: 3991 men and 1551 women aged 25-64 years on the Glasgow MONICA coronary event register with definite or fatal possible or unclassifiable events according to the criteria of the World Health Organisation's MONICA project (monitoring trends and determinants in cardiovascular disease). MAIN OUTCOME MEASURES: Rate of coronary events; proportion of subjects reaching hospital alive; case fatality in admitted patients and in community overall. RESULTS: Event rates increased with age for both sexes and were greater in men than women at all ages. The rate increased 1.7-fold in men and 2.4-fold in women from the least (Q1) to the most (Q4) deprived socioeconomic quarter. The socioeconomic gradient decreased with age and was steeper for women than men. The proportion treated in hospital (66%) decreased with age, was greater in women than men, and decreased in both sexes with increasing deprivation (age standardised odds ratio 0.82 for Q4 v Q1) Case fatality in hospital (20%) increased with age, was greater for women than men when age was standardised, and showed no strong socioeconomic pattern. Overall case fatality in the community (50%) increased with age, was similar between the sexes, and increased from Q1 to Q4 (age standardised odds ratio 1.12 in men, 1.18 in women). CONCLUSIONS: Socioeconomic group affects not only death rates from myocardial infarction but also event rates and chance of admission. This should be taken into account when different groups of patients are compared. Because social deprivation is associated with so many more deaths outside hospital, primary and secondary prevention are more likely than acute hospital care to reduce the socioeconomic variation in mortality. PMID:9055711

Q fever is an old and neglected zoonotic disease in Kenya: a systematic review.

PubMed

Njeru, J; Henning, K; Pletz, M W; Heller, R; Neubauer, H

2016-04-05

Q fever is a neglected zoonosis caused by the bacterium Coxiella burnetii. The knowledge of the epidemiology of Q fever in Kenya is limited with no attention to control and prevention programs. The purpose of this review is to understand the situation of Q fever in human and animal populations in Kenya in the past 60 years, and help identify future research priorities for the country. Databases were searched for national and international scientific studies or reports on Q fever. We included studies and reports published between 1950 and 2015 if they reported on Q fever prevalence, incidence, and infection control programs in Kenya. Data were extracted with respect to studies on prevalence of Coxiella infections, study design, study region, the study populations involved, and sorted according to the year of the study. We identified 15 studies and reports which qualified for data extraction. Human seroprevalence studies revealed evidence of C. burnetii infections ranging from 3 to 35.8% in all regions in which surveys were made and two Q fever outbreak episodes. Coxiella burnetii infections found in cattle 7.4-51.1%, sheep 6.7-20%, camels 20-46%, and goats 20-46% revealed variation based on ecoregions and the year of study. Farming and lack of protective clothing were associated with increased seropositivity among humans. However, high quality data is lacking on Q fever awareness, underlying cultural-economic factors influencing C. burnetii infection, and how the pathogen cycles may be embedded in livestock production and management systems in the economically and ecologically different Kenyan regions. We found no studies on national disease incidence estimates or disease surveillance and control efforts. Coxiella burnetii infections are common in human and in a wide range of animal populations but are still unrecognized and underestimated thus presenting a significant human and animal health threat in Kenya. The factors influencing pathogen transmission, persistence and spread are poorly understood. Integrated disease surveillance and prevention/control programs are needed in Kenya.

Unusual properties of high-compliance porosity extracted from measurements of pressure-dependent wave velocities in rocks

NASA Astrophysics Data System (ADS)

Zaitsev, Vladimir Y.; Radostin, Andrey V.; Pasternak, Elena; Dyskin, Arcady

2016-04-01

Conventionally the interpretation of wave velocities and their variations under load is conducted assuming that closable cracks have simple planar shapes, like the popular model of penny-shape cracks. For such cracks, the proportion between complementary variations in different elastic parameters of rocks (such as S- and P-wave velocities) is strictly pre-determined, in particular, it is independent of the crack aspect ratio and rather weakly dependent on the Poisson's ratio of the intact rock. Real rocks, however, contain multitude of cracks of different geometry. Faces of such cracks can exhibit complex modes of interaction when closed by external load, which may result in very different ratios between normal- and shear compliances of such defects. In order to describe the reduction of different elastic moduli, we propose a model in which the compliances of crack-like defects are explicitly decoupled and are not predetermined, so that the ratio q between total normal- and shear- compliances imparted to the rock mass (as well as individual values of these compliances) can be estimated from experimental data on reduction of different elastic moduli (e.g., pressure dependences of P- and S-wave velocities). Physically, the so-extracted ratio q can be interpreted as intrinsic property of individual crack-like defects similar to each other, or as a characteristic of proportion between concentrations of pure normal cracks with very large q and pure shear cracks with q→0. The latter case can correspond, e.g., to saturated cracks in which weakly-compressible liquid prevents crack closing under normal loading. It can be shown that for conventional dry planar cracks, the compliance ratio is q ˜2. The developed model applied to the data on wave-velocity variations with external pressure indicates that elastic properties of the real crack-like defects in rocks can differ considerably from the usually assumed ones. Comparison with experimental data on variations P- and S-wave velocities with hydrostatic compression of different dry and saturated rocks (sandstones, Westerly granite and Webatuck dolomite, etc.) shows that our model is accurate in a wide range of pressures with constant (i.e., pressure-independent) values of parameter q. Furthermore, the determined values of the latter are considerably different from those of conventional cracks. In particular, although all saturated samples have values q <1, the simplified approximation q=0 (i.e., the absence of normal compressibility that is often assumed for wet cracks) leads to large errors in the prediction of complementary variations in the shear- and bulk elastic moduli. Among dry sandstones, the majority have q >2 and many sandstones exhibit unusually high q»1 suggesting quite rough and tortoise nature of real cracks in those rocks. We demonstrate that in such cases, the use of the conventional assumption q ˜2 typical of penny-shape cracks leads to striking inconsistency between the predicted and experimentally observed crack-induced complementary variations in different elastic moduli. Furthermore, among samples with q»1, we revealed numerous examples that demonstrate negative Poisson's ratio at low pressures. VYZ and AVR acknowledge the financial support by RFBR grant No 15-05-05143.

Pseudo-myocardial infarction in diabetic ketoacidosis with hyperkalemia.

PubMed

Bellazzini, Marc A; Meyer, Tom

2010-10-01

Hyperkalemia-induced electrocardiogram changes such as dysrhythmias and altered T wave morphology are well described in the medical literature. Pseudo-infarction hyperkalemia-induced changes are less well known, but present a unique danger for the clinician treating these critically ill patients. This article describes a case of pseudo anteroseptal myocardial infarction in a type 1 diabetic with hyperkalemia. The most common patterns of pseudo-infarct and their associated potassium concentrations are then summarized from a literature review of 24 cases. Copyright © 2010 Elsevier Inc. All rights reserved.

Initiation and structures of gaseous detonation

NASA Astrophysics Data System (ADS)

Vasil'ev, A. A.; Vasiliev, V. A.

2018-03-01

The analysis of the initiation of a detonation wave (DW) and the emergence of a multi-front structure of the DW-front are presented. It is shown that the structure of the DW arises spontaneously at the stage of a strong overdriven of the wave. The hypothesis of the gradual enhancement of small perturbations on an initially smooth initiating blast wave, traditionally used in the numerical simulation of multi-front detonation, does not agree with the experimental data. The instability of the DW is due to the chemical energy release of the combustible mixture Q. A technique for determining the Q-value of mixture was proposed, based on reconstruction of the trajectory of the expanding wave from the position of the strong explosion model. The wave trajectory at the critical initiation of a multifront detonation in a combustible mixture is compared with the trajectory of an explosive wave from the same initiator in an inert mixture whose gas-dynamic parameters are equivalent to the parameters of the combustible mixture. The energy release of a mixture is defined as the difference in the joint energy release of the initiator and the fuel mixture during the critical initiation and energy release of the initiator when the blast wave is excited in an inert mixture. Observable deviations of the experimental profile of Q from existing model representations were found.

The role of momentum transfer during incoherent neutron scattering is explained by the energy landscape model

PubMed Central

Frauenfelder, Hans; Young, Robert D.; Fenimore, Paul W.

2017-01-01

We recently introduced a model of incoherent quasielastic neutron scattering (QENS) that treats the neutrons as wave packets of finite length and the protein as a random walker in the free energy landscape. We call the model ELM for “energy landscape model.” In ELM, the interaction of the wave packet with a proton in a protein provides the dynamic information. During the scattering event, the momentum Q(t) is transferred by the wave packet to the struck proton and its moiety, exerting the force F(t)=dQ(t)/dt. The resultant energy E⋆ is stored elastically and returned to the neutron as it exits. The energy is given by E⋆=kB(T0+χQ), where T0 is the ambient temperature and χ (≈ 91 K Å) is a new elastobaric coefficient. Experiments yield the scattering intensity (dynamic structure factor) S(Q;T) as a function of Q and T. To test our model, we use published data on proteins where only thermal vibrations are active. ELM competes with the currently accepted theory, here called the spatial motion model (SMM), which explains S(Q,T) by motions in real space. ELM is superior to SMM: It can explain the experimental angular and temperature dependence, whereas SMM cannot do so. PMID:28461503

Techniques for measuring the atomic recoil frequency using a grating-echo atom interferometer

NASA Astrophysics Data System (ADS)

Barrett, Brynle

I have developed three types of time-domain echo atom interferometer (AIs) that use either two or three standing-wave pulses in different configurations. Experiments approaching the transit time limit are achieved using samples of laser-cooled rubidium atoms with temperatures < 5 μK contained within a glass vacuum chamber—an environment that is largely free of both magnetic fields and field gradients. The principles of the atom-interferometric measurement of Eq can be understood based on a description of the "two-pulse" AI. This interferometer uses two standing-wave pulses applied at times t = 0 and t = T 21 to create a superposition of atomic momentum states differing by multiples of the two-photon momentum, ħq = 2 ħk where k is the optical wave number, that interfere in the vicinity of t = 2T 21. This interference or "echo" manifests itself as a density grating in the atomic sample, and is probed by applying a near-resonant traveling-wave "read-out" pulse and measuring the intensity of the coherent light Bragg-scattered in the backward direction. The scattered light from the grating is associated with a λ/2-periodic modulation produced by the interference of momentum states differing by ħq. Interfering states that differ by more than ħq—which produce higher-frequency spatial modulation within the sample—cannot be detected due to the nature of the Bragg scattering detection technique employed in the experiment. The intensity of the scattered light varies in a periodic manner as a function of the standing-wave pulse separation, T21. The fundamental frequency of this modulation is the two-photon atomic recoil frequency, ω q = ħq2/2M, where q = 2k and M is the mass of the atom (a rubidium isotope in this case). The recoil frequency, ω q, is related to the recoil energy, Eq = ħωq, which is the kinetic energy associated with the recoil of the atom after a coherent two-photon scattering process. By performing the experiment on a suitably long time scale ( T21 >> τq = π/ω q ˜32 μs), ωq can be measured precisely. Since ωq contains the ratio of Planck's constant to the mass of the atom, h/M, a precise measurement of ωq can be used as a strict test of quantum theories of the electromagnetic force. This two-pulse technique has a number of disadvantages for a precision measurement of ωq, such as a complicated functional dependence on T21 (due to the nature of Kapitza-Dirac diffraction, the level structure of the atom, and spontaneous emission). However, many of these difficulties can be avoided by using a three-pulse "perturbative" echo technique, where a third standing-wave pulse is applied at t = T21 + δT , with δT < T21. The function of the third pulse is to convert the difference between interfering momentum states from nħq (n > 1) to ħq. In this manner, interference between high-order momentum states contributes more significantly to the three-pulse echo than to the two-pulse echo. By fixing T21 and varying δT between the second standing-wave pulse and the echo time, the signal exhibits a simple shape with narrow fringes that revive periodically at the recoil period, τq. Using this technique, I have achieved a single measurement of ωq with a relative statistical uncertainty of ˜ 180 parts per 109 (ppb) on a time scale of 2T21 ˜ 72 ms in ˜ 15 minutes of data acquisition. Further improvements are anticipated by extending the experimental time scale and narrowing the signal fringe width. To demonstrate the final statistical uncertainty using the current configuration of the experiment, I acquired 82 individual measurements of ω q under the same experimental conditions. This resulted in a final measurement with a statistical precision of 37 ppb. However, this measurement is currently overwhelmed by systematic errors at the level of ˜ 5.7 parts per 106 (ppm). The first survey of systematic effects on the measurement of ωq with this technique has also been carried out, where individual measurements had relative statistical uncertainties of ≲ 1 ppm. These experimental studies, along with theoretical calculations, can be used to reduce and eliminate such effects in future rounds of experimentation. (Abstract shortened by UMI.).

Nonlinear dynamics near the stability margin in rotating pipe flow

NASA Technical Reports Server (NTRS)

Yang, Z.; Leibovich, S.

1991-01-01

The nonlinear evolution of marginally unstable wave packets in rotating pipe flow is studied. These flows depend on two control parameters, which may be taken to be the axial Reynolds number R and a Rossby number, q. Marginal stability is realized on a curve in the (R, q)-plane, and the entire marginal stability boundary is explored. As the flow passes through any point on the marginal stability curve, it undergoes a supercritical Hopf bifurcation and the steady base flow is replaced by a traveling wave. The envelope of the wave system is governed by a complex Ginzburg-Landau equation. The Ginzburg-Landau equation admits Stokes waves, which correspond to standing modulations of the linear traveling wavetrain, as well as traveling wave modulations of the linear wavetrain. Bands of wavenumbers are identified in which the nonlinear modulated waves are subject to a sideband instability.

Extreme Right Axis Deviation in Acute Myocardial Infarction: A Hazardous Signal of Poor Prognosis.

PubMed

Wang, Qingyu; Pan, Shuo; Liu, Fuqiang; Yang, Dan; Wang, Jun-Kui

2018-05-11

BACKGROUND New-onset extreme right axis deviation and right bundle branch block (RBBB) are rare during acute myocardial infarction (AMI), and has only been reported in several cases reflecting the severity of AMI. It could predict severe clinical complications and higher risks in coronary artery disease. Although there is little electrophysiological explanation, the complications are severe. They should be emphasized in newly diagnosed extreme right axis deviation and RBBB in AMI. CASE REPORT A 72-year-old male was admitted to our department with a chief complaint of intermittent retrosternal chest pain and was diagnosed with extensive anterior myocardial infarction with RBBB, by elevated myocardial enzymes and ECG. The main wave direction of QRS in lead aVR was positive and showed an extreme right axis deviation. After a month, the patient's chest distress and the RBBB vanished, but a right axis deviation still existed. The echocardiogram showed prior extensive anterior myocardial infarction (including apex myocardia) and lower LVEF. CONCLUSIONS New diagnosed RBBB and right axis deviation is uncommon and could be a useful clue to evaluate myocardial ischemia in AMI cases. This electrocardiographic marker can identify coronary artery occlusion where ST-segments are hard to evaluate, and hence, patients may benefit most from early and complete revascularization strategies such as primary angioplasty.

Imaging the propagation of the electromechanical wave in heart failure patients with cardiac resynchronization therapy

PubMed Central

Bunting, Ethan; Lambrakos, Litsa; Kemper, Paul; Whang, William; Garan, Hasan; Konofagou, Elisa

2016-01-01

Background Current electrocardiographic and echocardiographic measurements in heart failure (HF) do not take into account the complex interplay between electrical activation and local wall motion. The utilization of novel technologies to better characterize cardiac electromechanical behavior may lead to improved response rates with cardiac resynchronization therapy (CRT). Electromechanical Wave Imaging (EWI) is a non-invasive ultrasound-based technique that uses the transient deformations of the myocardium to track the intrinsic electromechanical wave that precedes myocardial contraction. In this paper, we investigate the performance and reproducibility of EWI in the assessment of HF patients and CRT. Methods EWI acquisitions were obtained in 5 healthy controls and 16 HF patients with and without CRT pacing. Responders (n=8) and non-responders (n=8) to CRT were identified retrospectively on the basis of left ventricular (LV) reverse remodeling. Electromechanical activation maps were obtained in all patients and used to compute a quantitative parameter describing the mean activation time of the LV lateral wall (LWAT). Results Mean LWAT was increased by 52.1 ms in HF patients in native rhythm compared to controls (p<0.01). For all HF patients, CRT pacing initiated a different electromechanical activation sequence. Responders exhibited a 56.4±28.9 ms reduction in LWAT with CRT pacing (p<0.01), while non-responders showed no significant change. Conclusion In this initial feasibility study, EWI was capable of characterizing local cardiac electromechanical behavior as it pertains to HF and CRT response. Activation sequences obtained with EWI allow for quantification of LV lateral wall electromechanical activation, thus providing a novel method for CRT assessment. PMID:27790723

Ultra-high-Q phononic resonators on-chip at cryogenic temperatures

NASA Astrophysics Data System (ADS)

Kharel, Prashanta; Chu, Yiwen; Power, Michael; Renninger, William H.; Schoelkopf, Robert J.; Rakich, Peter T.

2018-06-01

Long-lived, high-frequency phonons are valuable for applications ranging from optomechanics to emerging quantum systems. For scientific as well as technological impact, we seek high-performance oscillators that offer a path toward chip-scale integration. Confocal bulk acoustic wave resonators have demonstrated an immense potential to support long-lived phonon modes in crystalline media at cryogenic temperatures. So far, these devices have been macroscopic with cm-scale dimensions. However, as we push these oscillators to high frequencies, we have an opportunity to radically reduce the footprint as a basis for classical and emerging quantum technologies. In this paper, we present novel design principles and simple microfabrication techniques to create high performance chip-scale confocal bulk acoustic wave resonators in a wide array of crystalline materials. We tailor the acoustic modes of such resonators to efficiently couple to light, permitting us to perform a non-invasive laser-based phonon spectroscopy. Using this technique, we demonstrate an acoustic Q-factor of 2.8 × 107 (6.5 × 106) for chip-scale resonators operating at 12.7 GHz (37.8 GHz) in crystalline z-cut quartz (x-cut silicon) at cryogenic temperatures.

Impact of type 2 diabetes mellitus on recurrent myocardial infarction in China.

PubMed

Li, Wentao; Li, Muwei; Gao, Chuanyu; Wang, Xianpei; Qi, Datun; Liu, Jun; Jin, Qiangsong

2016-11-01

To evaluate the influence of type 2 diabetes mellitus on the long-term outcomes of Chinese patients with previous myocardial infarction, we studied 864 patients with previous myocardial infarction, including 251 with type 2 diabetes mellitus and 613 without type 2 diabetes mellitus, over a median follow-up time of 2.9 years. The type 2 diabetes mellitus patients were subdivided into 95 insulin-treated diabetes mellitus and 156 non-insulin-treated diabetes mellitus subjects. The crude incidences (per 1000 patient-years) in the type 2 diabetes mellitus subjects versus the non-type 2 diabetes mellitus subjects were 43.7 versus 25.1 for recurrent myocardial infarction, 68.7 versus 28.3 for all-cause death and 99.8 versus 49.9 for the composite end point (i.e. recurrent myocardial infarction or all-cause death). Cox regression analysis showed that the adjusted hazard ratios for recurrent myocardial infarction, all-cause death and their combination were 1.67 (95% confidence interval: 1.06-2.74), 1.90 (1.25-2.90) and 1.72 (1.23-2.40), respectively. Significant associations were also observed between insulin treatment and all-cause death. Our findings suggested that type 2 diabetes mellitus is an independent risk factor for recurrent myocardial infarction, all-cause death and the composite end point among previous myocardial infarction patients. © The Author(s) 2016.

The influence of shear-velocity heterogeneity on ScS2/ScS amplitude ratios and estimates of Q in the mantle

NASA Astrophysics Data System (ADS)

Ritsema, J.; Chaves, C. A. M.

2016-12-01

Regional waveforms of deep-focus Tonga-Fiji earthquakes indicate anomalous traveltime differences (ScS2-ScS) and amplitude ratios (ScS2/ScS) of the phases ScS and ScS2. The correlation between the ScS2-ScS delay time and the ScS2/ScS amplitude ratio suggests that shear-wave apparent Q in the mantle below the Tonga-Fiji region is highest when shear-wave velocities are lowest. This observation is unexpected if temperature variations were responsible for the seismic anomalies. Using spectral-element-method waveform simulations for four tomographic models we demonstrate that focusing and scattering of shear waves by long-wavelength 3D heterogeneity in the mantle may overwhelm the signal from intrinsic attenuation in long-period ScS2/ScS amplitude ratios. The tomographic models reproduce the variability in recorded ScS2-ScS difference times and ScS2/ScS amplitude ratios. Variations in shear-wave attenuation (i.e., the quality factor Q) are not necessary to explain the data. An explanation for slow shear wave propagation without intrinsic attenuation does not require a creative solution from mineral physics.

Q-factor improvement of degenerate four-wave-mixing regenerators for ASE degraded signals

NASA Astrophysics Data System (ADS)

Lu, Hang; Wu, Bao-jian; Geng, Yong; Zhou, Xing-yu; Sun, Fan

2017-11-01

All-optical regenerators can be used to suppress amplified spontaneous emission (ASE) noise introduced by cascaded erbium doped fiber amplifiers (EDFAs) in optical fiber communication systems and lead to the improvement of optical receiver sensitivity. By introducing the Q-factor transfer function (QTF), we evaluate the Q-factor performance of degenerate four-wave mixing (DFWM) regenerators with clock pump and reveal the differences between the optimal input powers determined from the static and dynamic power tranfer function (PTF) and the QTF curves. Our simulation shows that the clock-pump regnerator is capable of improving the Q-facor and receiver sensitivity for 40 Gbit/s ASE-degraded return-to-zero on-off keying (RZ-OOK) signal by 2.58 dB and 4.2 dB, respectively.

[Instantaneous wave-free ratio (iFR®) in patients with coronary artery disease].

PubMed

Baumann, S; Schaefer, A C; Hohneck, A; Mueller, K; Becher, T; Behnes, M; Renker, M; Borggrefe, M; Akin, I; Lossnitzer, D

2017-08-23

Coronary angiography is considered as the gold standard in the morphological representation of coronary artery stenosis. Coronary angiography is often performed without preprocedural non-invasive proof of ischemia and the assessment of the severity of a coronary lesion by morphology is very subjective. Thus, invasive fractional flow reserve (FFR) measurement represents the current standard for estimation of the hemodynamic relevance of coronary artery stenosis and facilitates decision making for percutaneous coronary intervention (PCI) and stenting. The FFR-guided revascularization strategy has been classified as a class IA recommendation in the 2014 ESC/EACTS guidelines on myocardial revascularization. Both the DEFER and the FAME studies showed no treatment advantage of hemodynamically irrelevant stenosis. By use of FFR (and targeted interventions), clinical results could be improved as well as the procedure costs were reduced; however, the use in clinical practice is still limited due to the need of adenosine administration and a significant prolongation of the procedure. Instantaneous wave-free ratio (iFR®) is a new innovative approach for the determination of the hemodynamic relevance of coronary stenosis which can be obtained at rest without the use of vasodilators. Regarding periprocedural complications as well as prognosis, iFR® showed non-inferiority compared to FFR in the SWEDEHEART and DEFINE-FLAIR trials.

Waveform inversion for 3-D earth structure using the Direct Solution Method implemented on vector-parallel supercomputer

NASA Astrophysics Data System (ADS)

Hara, Tatsuhiko

2004-08-01

We implement the Direct Solution Method (DSM) on a vector-parallel supercomputer and show that it is possible to significantly improve its computational efficiency through parallel computing. We apply the parallel DSM calculation to waveform inversion of long period (250-500 s) surface wave data for three-dimensional (3-D) S-wave velocity structure in the upper and uppermost lower mantle. We use a spherical harmonic expansion to represent lateral variation with the maximum angular degree 16. We find significant low velocities under south Pacific hot spots in the transition zone. This is consistent with other seismological studies conducted in the Superplume project, which suggests deep roots of these hot spots. We also perform simultaneous waveform inversion for 3-D S-wave velocity and Q structure. Since resolution for Q is not good, we develop a new technique in which power spectra are used as data for inversion. We find good correlation between long wavelength patterns of Vs and Q in the transition zone such as high Vs and high Q under the western Pacific.

Region-specific S-wave attenuation for earthquakes in northwestern Iran

NASA Astrophysics Data System (ADS)

Heidari, Reza; Mirzaei, Noorbakhsh

2017-11-01

In this study, continuous wavelet transform is applied to estimate the frequency-dependent quality factor of shear waves, Q S , in northwestern Iran. The dataset used in this study includes velocigrams of more than 50 events with magnitudes between 4.0 and 6.5, which have occurred in the study area. The CWT-based method shows a high-resolution technique for the estimation of S-wave frequency-dependent attenuation. The quality factor values are determined in the form of a power law as Q S ( f) = (147 ± 16) f 0.71 ± 0.02 and (126 ± 12) f 0.73 ± 0.02 for vertical and horizontal components, respectively, where f is between 0.9 and 12 Hz. Furthermore, in order to verify the reliability of the suggested Q S estimator method, an additional test is performed by using accelerograms of Ahar-Varzaghan dual earthquakes on August 11, 2012, of moment magnitudes 6.4 and 6.3 and their aftershocks. Results indicate that the estimated Q S values from CWT-based method are not very sensitive to the numbers and types of waveforms used (velocity or acceleration).

[Myocardial perfusion imaging by digital subtraction angiography].

PubMed

Kadowaki, H; Ishikawa, K; Ogai, T; Katori, R

1986-03-01

Several methods of digital subtraction angiography (DSA) were compared to determine which could better visualize regional myocardial perfusion using coronary angiography in seven patients with myocardial infarction, two with angina pectoris and five with normal coronary arteries. Satisfactory DSA was judged to be achieved if the shape of the heart on the mask film was identical to that on the live film and if both films were exactly superimposed. To obtain an identical mask film in the shape of each live film, both films were selected from the following three phases of the cardiac cycle; at the R wave of the electrocardiogram, 100 msec before the R wave, and 200 msec before the R wave. The last two were superior for obtaining mask and live films which were similar in shape, because the cardiac motion in these phases was relatively small. Using these mask and live films, DSA was performed either with the continuous image mode (CI mode) or the time interval difference mode (TID mode). The overall perfusion of contrast medium through the artery to the vein was adequately visualized using the CI mode. Passage of contrast medium through the artery, capillary and vein was visualized at each phase using TID mode. Subtracted images were displayed and photographed, and the density of the contrast medium was adequate to display contour lines as in a relief map. Using this DSA, it was found that regional perfusion of the contrast medium was not always uniform in normal subjects, depending on the typography of the coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Epicardial shock-wave therapy improves ventricular function in a porcine model of ischaemic heart disease.

PubMed

Holfeld, Johannes; Zimpfer, Daniel; Albrecht-Schgoer, Karin; Stojadinovic, Alexander; Paulus, Patrick; Dumfarth, Julia; Thomas, Anita; Lobenwein, Daniela; Tepeköylü, Can; Rosenhek, Raphael; Schaden, Wolfgang; Kirchmair, Rudolf; Aharinejad, Seyedhossein; Grimm, Michael

2016-12-01

Previously we have shown that epicardial shock-wave therapy improves left ventricular ejection fraction (LVEF) in a rat model of myocardial infarction. In the present experiments we aimed to address the safety and efficacy of epicardial shock-wave therapy in a preclinical large animal model and to further evaluate mechanisms of action of this novel therapy. Four weeks after left anterior descending (LAD) artery ligation in pigs, the animals underwent re-thoracotomy with (shock-wave group, n = 6) or without (control group, n = 5) epicardial shock waves (300 impulses at 0.38 mJ/mm 2 ) applied to the infarcted anterior wall. Efficacy endpoints were improvement of LVEF and induction of angiogenesis 6 weeks after shock-wave therapy. Safety endpoints were haemodynamic stability during treatment and myocardial damage. Four weeks after LAD ligation, LVEF decreased in both the shock-wave (43 ± 3%, p < 0.001) and control (41 ± 4%, p = 0.012) groups. LVEF markedly improved in shock-wave animals 6 weeks after treatment (62 ± 9%, p = 0.006); no improvement was observed in controls (41 ± 4%, p = 0.36), yielding a significant difference. Quantitative histology revealed significant angiogenesis 6 weeks after treatment (controls 2 ± 0.4 arterioles/high-power field vs treatment group 9 ± 3; p = 0.004). No acute or chronic adverse effects were observed. As a potential mechanism of action in vitro experiments showed stimulation of VEGF receptors after shock-wave treatment in human coronary artery endothelial cells. Epicardial shock-wave treatment in a large animal model of ischaemic heart failure exerted a positive effect on LVEF improvement and did not show any adverse effects. Angiogenesis was induced by stimulation of VEGF receptors. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

Long Noncoding RNA MHRT Protects Cardiomyocytes against H2O2-Induced Apoptosis

PubMed Central

Zhang, Jianying; Gao, Caihua; Meng, Meijuan; Tang, Hongxia

2016-01-01

Acute myocardial infarction (AMI) remains a leading cause of morbidity and mortality worldwide. The exploration of new biomarkers with high sensitivity and specificity for early diagnosis of AMI therefore becomes one of the primary task. In the current study, we aim to detect whether there is any heart specific long noncoding RNA (lncRNA) releasing into the circulation during AMI, and explore its function in the neonatal rat cardiac myocytes injury induced by H2O2. Our results revealed that the cardiac-specific lncRNA MHRT (Myosin Heavy Chain Associated RNA Transcripts) was significantly elevated in the blood from AMI patients compared with the healthy control (*p<0.05). Using an in vitro neonatal rat cardiac myocytes injury model, we demonstrated that lncRNA MHRT was upregulated in the cardiac myocytes after treatment with hydrogen peroxide (H2O2) via real-time RT-PCR (qRT-PCR). Furthermore, we knockdowned the MHRT gene by siRNA to confirm its roles in the H2O2-induced cardiac cell apoptosis, and found that knockdown of MHRT led to significant more apoptotic cells than the non-target control (**p<0.01), indicating that the lncRNA MHRT is a protective factor for cardiomyocyte and the plasma concentration of MHRT may serve as a biomarker for myocardial infarction diagnosis in humans AMI. PMID:26759697

An experimental study of the protective effect of simvastatin on sepsis-induced myocardial depression in rats.

PubMed

Wang, Yu; Zhang, Lichun; Zhao, Xin; Yang, Wenping; Zhang, Rong

2017-10-01

Many patients with sepsis died of heart failure caused by sepsis-induced myocardial depression. Patients with cardiovascular diseases treated by statins have a lower incidence and mortality of sepsis, although the mechanisms remain elusive. To investigate the protective effect of simvastatin on sepsis-induced myocardial depression and to explore possible mechanisms of action. Thirty six adult male Wistar rats were pretreated with simvastatin (0.2μg/g, q12h) for one week before cecal ligation and puncture (CLP). It was found that in simvastatin-treated rats, cardiac function indices, including left ventricular systolic pressure (LVESP) and maximal rate of rise and fall of left ventricular pressure (±dp/dtmax) and mean arterial pressure(MAP) markedly improved. Myocardial cells examined with hematoxylin and eosin (HE) were only partially swollen and degenerated and with fewer inflammatory cells infiltrating. Expressions of TLR4 and NF-κB p65 protein were significantly lower in simvastatin-treated rats than that in sepsis rats at the same time point. Levels of TNF-α, IL-1β, IL-6, MCP-1 and NO in myocardial tissues, together with levels of CTnI in serum were significantly declined in simvastatin-treated rats. Simvastatin has a protective effect on myocardial depression caused by sepsis. The effect may be mediated by the inhibition of TLR4-NF-κB signaling pathway, which leads to reduced levels of downstream inflammatory factors such as TNF-α, IL-1β, IL-6, MCP-1 and NO. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

A Millimeter Wave BPF using WG Mode High Permittivity Dielectric Resonators

NASA Astrophysics Data System (ADS)

Sato, Yosuke; Kogami, Yoshinori; Tomabechi, Yoshiro; Matsumura, Kazuhito

In this paper, a design technique of whispering gallery mode high Q value dielectric disk resonators for a millimeter-wave bandpass filter is described. To minimize the resonator size, some high permittivity materials are used. In this resonator design, unloaded Q value of an interested mode and the higher order modes are calculated and then optimum resonator size for the WG mode dielectric filter is determined. For a designed resonator, the higher order modes are hardly excited while the Q value of the fundamental mode can be maximized. Finally, some 3stage BPFs are constructed at 60GHz by using these designed resonators.

Continuous-wave and actively Q-switched resonantly dual-end-pumped Er : YAG ceramic laser emitting at 1.6 μm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai, T Y; Deng, Yu; Ju, Y-L

2015-12-31

We demonstrate a continuous-wave (cw) and actively Q-switched Er : YAG ceramic laser resonantly dual-end-pumped by a 1532 nm fibre-coupled laser diode. A maximum cw output power of 1.48 W at 1645.3 nm is obtained at an absorbed pump power of 12.72 W, corresponding to a slope efficiency of 19.2%. In the Q-switched regime the maximum pulse energy of 0.84 mJ is reached at a pulse repetition rate of 100 Hz, pulse duration of 48.03 ns and absorbed pump power of 10.51 W. (lasers)

Rogue Waves in Multi-Ion Cometary Plasmas

NASA Astrophysics Data System (ADS)

Sreekala, G.; Manesh, M.; Neethu, T. W.; Anu, V.; Sijo, S.; Venugopal, C.

2018-01-01

The effect of pair ions on the formation of rogue waves in a six-component plasma composed of two hot and one colder electron component, hot ions, and pair ions is studied. The kappa distribution, which provides an unambiguous replacement for a Maxwellian distribution in space plasmas, is connected with nonextensive statistical mechanics and provides a continuous energy spectrum. Hence, the colder and one component of the hotter electrons is modeled by kappa distributions and the other hot electron component, by a q-nonextensive distribution. It is found that the rogue wave amplitude is different for various pair-ion components. The magnitude, however, increases with increasing spectral index and nonextensive parameter q. These results may be useful in understanding the basic characteristics of rogue waves in cometary plasmas.

Internal transport barrier triggered by non-linear lower hybrid wave deposition under condition of beam-driven toroidal rotation

NASA Astrophysics Data System (ADS)

Gao, Q. D.; Budny, R. V.

2015-03-01

By using gyro-Landau fluid transport model (GLF23), time-dependent integrated modeling is carried out using TRANSP to explore the dynamic process of internal transport barrier (ITB) formation in the neutral beam heating discharges. When the current profile is controlled by LHCD (lower hybrid current drive), with appropriate neutral beam injection, the nonlinear interplay between the transport determined gradients in the plasma temperature (Ti,e) and toroidal velocity (Vϕ) and the E×B flow shear (including q-profile) produces transport bifurcations, generating spontaneously a stepwise growing ITB. In the discharge, the constraints imposed by the wave propagation condition causes interplay of the LH driven current distribution with the plasma configuration modification, which constitutes non-linearity in the LH wave deposition. The non-linear effects cause bifurcation in LHCD, generating two distinct quasi-stationary reversed magnetic shear configurations. The change of current profile during the transition period between the two quasi-stationary states results in increase of the E×B shearing flow arising from toroidal rotation. The turbulence transport suppression by sheared E×B flow during the ITB development is analysed, and the temporal evolution of some parameters characterized the plasma confinement is examined. Ample evidence shows that onset of the ITB development is correlated with the enhancement of E×B shearing rate caused by the bifurcation in LHCD. It is suggested that the ITB triggering is associated with the non-linear effects of the LH power deposition.

Endocardial Hippo signaling regulates myocardial growth and cardiogenesis.

PubMed

Artap, Stanley; Manderfield, Lauren J; Smith, Cheryl L; Poleshko, Andrey; Aghajanian, Haig; See, Kelvin; Li, Li; Jain, Rajan; Epstein, Jonathan A

2018-08-01

The Hippo signaling pathway has been implicated in control of cell and organ size, proliferation, and endothelial-mesenchymal transformation. This pathway impacts upon two partially redundant transcription cofactors, Yap and Taz, that interact with other factors, including members of the Tead family, to affect expression of downstream genes. Yap and Taz have been shown to regulate, in a cell-autonomous manner, myocardial proliferation, myocardial hypertrophy, regenerative potential, and overall size of the heart. Here, we show that Yap and Taz also play an instructive, non-cell-autonomous role in the endocardium of the developing heart to regulate myocardial growth through release of the paracrine factor, neuregulin. Without endocardial Yap and Taz, myocardial growth is impaired causing early post-natal lethality. Thus, the Hippo signaling pathway regulates cell size via both cell-autonomous and non-cell-autonomous mechanisms. Furthermore, these data suggest that Hippo may regulate organ size via a sensing and paracrine function in endothelial cells. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Kelvin-Mach Wake in a Two-Dimensional Fermi Sea

NASA Astrophysics Data System (ADS)

Kolomeisky, Eugene B.; Straley, Joseph P.

2018-06-01

The dispersion law for plasma oscillations in a two-dimensional electron gas in the hydrodynamic approximation interpolates between Ω ∝√{q } and Ω ∝q dependences as the wave vector q increases. As a result, downstream of a charged impurity in the presence of a uniform supersonic electric current flow, a wake pattern of induced charge density and potential is formed whose geometry is controlled by the Mach number M . For 1 √{2 }. These wakes also trail an external charge, traveling supersonically, a fixed distance away from the electron gas.

The Role of Alcohol Consumption in the Aetiology of Different Cardiovascular Disease Phenotypes: a CALIBER Study

ClinicalTrials.gov

2013-05-28

Chronic Stable Angina; Unstable Angina; Coronary Heart Disease Not Otherwise Specified; Acute Myocardial Infarction; Heart Failure; Ventricular Arrhythmias; Cardiac Arrest; Abdominal Aortic Aneurysm; Peripheral Arterial Disease; Ischaemic Stroke; Subarachnoid Haemorrhagic Stroke; Intracerebral Haemorrhagic Stroke; Stroke Not Otherwise Specified; Sudden Cardiac Death; Unheralded Coronary Death; Mortality; Coronary Heart Disease (CHD); Cardiovascular Disease (CVD); Fatal Cardiovascular Disease (Fatal CVD); ST Elevation Myocardial Infarction (STEMI); Non-ST Elevation Myocardial Infarction (nSTEMI); Myocardial Infarction Not Otherwise Specified (MI NOS)

Discussion paper: The kink oscillations of the thin nonuniform coronal loops

NASA Astrophysics Data System (ADS)

Mikhalyaev, B. B.

2006-12-01

[1] MHD-oscillations of an inhomogeneous coronal loop consisting of a dense cord and a surrounding shell are investigated. Magnetic field in the cord is longitudinal and in the shell is azimuthal only. Usually the nonuniform field leads to the existence of resonance. However here we assume the resonance points non exist in the tube, i.e. the resonances are cutted. Our approach pursue a target - an investigation of an influence of the wave radiation on the tube oscillations. The resonant absorption of tube oscillation energy is eliminated. The same tube effectively radiate a magnetosonic waves into the environment and the Q-factor of the tube oscillations is small. The presented model can explain the fast damping of the coronal loop oscillations observed by the TRACE EUV channel.

[Lethal myocardial injury associated with hydrogen sulfide poisoning: report of two cases].

PubMed

Inoue, Yukinori; Kumagai, Ken; Tanaka, Toshiharu; Yoshida, Satoru; Sekiguchi, Hiroshi; Kobayashi, Kaori; Hirose, Yasuo

2011-09-01

We investigated two cases of hydrogen sulfide poisoning in which the patients showed lethal myocardial injury. Both patients had planned to commit suicide by inhaling hydrogen sulfide. In case 1, a 17-year-old man was confused and was brought to our hospital by ambulance. An electrocardiogram (ECG) revealed diffuse elevation of the ST segment on the second hospital day. The patient recovered and was discharged from the hospital on the 15th day. However, he died suddenly on the 18th day. In case 2, a 21-year-old man was found lying on the floor and was admitted to our hospital. ECG showed tall T waves after 5 hr. Tachycardia and tachypnea occurred after 12 hr. After 16 hr, the ECG showed a marked elevation of the ST segment, and the patient developed cardiac arrest. Even though percutaneous cardiopulmonary support was used, he died on the 4th day. It is highly probable that myocardial injury asscociated with hydrogen sulfide poisoning was not caused by systemic hypoxia but by selective myocardial toxicity. These cases demonstrate that delayed presentation of a lethal myocardial injury should be considered while treating cases of hydrogen sulfide poisoning.

Electron acoustic nonlinear structures in planetary magnetospheres

NASA Astrophysics Data System (ADS)

Shah, K. H.; Qureshi, M. N. S.; Masood, W.; Shah, H. A.

2018-04-01

In this paper, we have studied linear and nonlinear propagation of electron acoustic waves (EAWs) comprising cold and hot populations in which the ions form the neutralizing background. The hot electrons have been assumed to follow the generalized ( r , q ) distribution which has the advantage that it mimics most of the distribution functions observed in space plasmas. Interestingly, it has been found that unlike Maxwellian and kappa distributions, the electron acoustic waves admit not only rarefactive structures but also allow the formation of compressive solitary structures for generalized ( r , q ) distribution. It has been found that the flatness parameter r , tail parameter q , and the nonlinear propagation velocity u affect the propagation characteristics of nonlinear EAWs. Using the plasmas parameters, typically found in Saturn's magnetosphere and the Earth's auroral region, where two populations of electrons and electron acoustic solitary waves (EASWs) have been observed, we have given an estimate of the scale lengths over which these nonlinear waves are expected to form and how the size of these structures would vary with the change in the shape of the distribution function and with the change of the plasma parameters.

Data dependence for the amplitude equation of surface waves

NASA Astrophysics Data System (ADS)

Secchi, Paolo

2016-04-01

We consider the amplitude equation for nonlinear surface wave solutions of hyperbolic conservation laws. This is an asymptotic nonlocal, Hamiltonian evolution equation with quadratic nonlinearity. For example, this equation describes the propagation of nonlinear Rayleigh waves (Hamilton et al. in J Acoust Soc Am 97:891-897, 1995), surface waves on current-vortex sheets in incompressible MHD (Alì and Hunter in Q Appl Math 61(3):451-474, 2003; Alì et al. in Stud Appl Math 108(3):305-321, 2002) and on the incompressible plasma-vacuum interface (Secchi in Q Appl Math 73(4):711-737, 2015). The local-in-time existence of smooth solutions to the Cauchy problem for the amplitude equation in noncanonical variables was shown in Hunter (J Hyperbolic Differ Equ 3(2):247-267, 2006), Secchi (Q Appl Math 73(4):711-737, 2015). In the present paper we prove the continuous dependence in strong norm of solutions on the initial data. This completes the proof of the well-posedness of the problem in the classical sense of Hadamard.

Dust-acoustic waves and stability in the permeating dusty plasma. II. Power-law distributions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gong Jingyu; Du Jiulin; Liu Zhipeng

2012-08-15

The dust-acoustic waves and the stability theory for the permeating dusty plasma with power-law distributions are studied by using nonextensive q-statistics. In two limiting physical cases, when the thermal velocity of the flowing dusty plasma is much larger than, and much smaller than the phase velocity of the waves, we derived the dust-acoustic wave frequency, the instability growth rate, and the instability critical flowing velocity. As compared with the formulae obtained in part I [Gong et al., Phys. Plasmas 19, 043704 (2012)], all formulae of the present cases and the resulting plasma characteristics are q-dependent, and the power-law distribution ofmore » each plasma component of the permeating dusty plasma has a different q-parameter and thus has a different nonextensive effect. Further, we make numerical analyses of an example that a cometary plasma tail is passing through the interplanetary space dusty plasma and we show that these power-law distributions have significant effects on the plasma characteristics of this kind of plasma environment.« less

Non-Invasive Detection of Risk for Emotion Provoked Myocardial Ischemia

PubMed Central

Burg, Matthew M.; Graeber, Brendon; Vashist, Aseem; Collins, Dorothea; Earley, Christine; Liu, Joyce; Lampert, Rachel; Soufer, Robert

2009-01-01

Objectives To test an easily administered, noninvasive technology to identify vulnerability to mental stress ischemia. Background Myocardial ischemia provoked by emotional stress (MSI) in patients with stable coronary artery disease (CAD) predicts major adverse cardiac events. A clinically useful tool to risk stratify patients on this factor is not available. Methods Patients with documented CAD (n=68) underwent single photon emission computed tomography (SPECT) myocardial perfusion imaging concurrent with pulse wave amplitude assessment by peripheral arterial tonometry (PAT) during a mental stress protocol of sequential rest and anger stress periods. Heart rate and blood pressure were assessed, and blood was drawn for catecholamine assay, during rest and stress. MSI was defined by the presence of a new perfusion defect during anger stress (n=26) and the ratio of stress to rest PAT response was calculated. Results Patients with MSI had a significantly lower PAT ratio than those without MSI (0.76 ± 0.04 vs. 0.91 ± 0.05, p=0.03). An ROC curve for optimum sensitivity/specificity of PAT ratio as an index of MSI produced a sensitivity of 0.62 and a specificity of 0.63. Among patients taking angiotensin converter enzyme (ACE) inhibitors, the sensitivity and specificity of the test increased to 0.86 and 0.73 (respectively); 90% of patients without MSI were correctly identified. Conclusions PAT in concert with ACE inhibition may provide a useful approach to assess risk for MSI. Future studies should help determine how best to utilize this approach for risk assessment in the clinical setting. PMID:18941131

Characterization of ventricular depolarization and repolarization changes in a porcine model of myocardial infarction.

PubMed

Romero, Daniel; Ringborn, Michael; Demidova, Marina; Koul, Sasha; Laguna, Pablo; Platonov, Pyotr G; Pueyo, Esther

2012-12-01

In this study, several electrocardiogram (ECG)-derived indices corresponding to both ventricular depolarization and repolarization were evaluated during acute myocardial ischemia in an experimental model of myocardial infarction produced by 40 min coronary balloon inflation in 13 pigs. Significant changes were rapidly observed from minute 4 after the start of coronary occlusion, achieving their maximum values between 11 and 22 min for depolarization and between 9 and 12 min for repolarization indices, respectively. Subsequently, these maximum changes started to decrease during the latter part of the occlusion. Depolarization changes associated with the second half of the QRS complex showed a significant but inverse correlation with the myocardium at risk (MaR) estimated by scintigraphic images. The correlation between MaR and changes of the downward slope of the QRS complex, [Formula: see text], evaluated at the two more relevant peaks observed during the occlusion, was r = -0.75, p < 0.01 and r = -0.79, p < 0.01 for the positive and negative deflections observed in [Formula: see text], temporal evolution, respectively. Repolarization changes, analyzed by evaluation of ST segment elevation at the main observed positive peak, also showed negative, however non-significant correlation with MaR: r = -0.34, p = 0.28. Our results suggest that changes evaluated in the latter part of the depolarization, such as those described by [Formula: see text], which are influenced by R-wave amplitude, QRS width and ST level variations simultaneously, correlate better with the amount of ischemia than other indices evaluated in the earlier part of depolarization or during the ST segment.

Vasospasm of atherosclerotic coronary arteries precipitates acute ischemic myocardial damage in myocardial infarction-prone strain of the Watanabe heritable hyperlipidemic rabbits.

PubMed

Shiomi, Masashi; Ishida, Tatsuro; Kobayashi, Tsutomu; Nitta, Norihisa; Sonoda, Akinaga; Yamada, Satoshi; Koike, Tomonari; Kuniyoshi, Nobue; Murata, Kiyoshi; Hirata, Ken-ichi; Ito, Takashi; Libby, Peter

2013-11-01

This study tested the hypothesis that vasospasm can trigger coronary plaque injury and acute ischemic myocardial damage. Myocardial infarction-prone strain of the Watanabe heritable hyperlipidemic rabbits received an intravenous bolus of ergonovine maleate (0.45 µmol/kg) during intravenous infusion of norepinephrine (12 nmol/kg per minute) to provoke coronary spasm in vivo. After this treatment, coronary angiography demonstrated vasospasm, and the ECG showed ischemic abnormalities (ST depression/elevation and T-wave inversion) in 77% of animals (23/30). These changes normalized after nitroglycerin injection. In rabbits that demonstrated these ECG findings for >20 minutes, echocardiograms showed left ventricular wall motion abnormality. Serum levels of heart-type fatty acid-binding protein, cardiac troponin-I, and myoglobin increased markedly 4 hours after spasm provocation. In coronary lesions of myocardial infarction-prone strain of the Watanabe heritable hyperlipidemic rabbits with provoked coronary spasm, we observed intimal injury in 60.9% in the form of endothelial cell protrusions (39.1%), denudation (30.4%), and macrophage extravasation (56.5%). Plaque disruption with luminal thrombus, however, was only seen in 2 of 23 animals (8.7%), and mural microthrombus was rarely observed (4.3%). These observations show that provocation of vasospasm in myocardial infarction-prone strain of the Watanabe heritable hyperlipidemic rabbits associates with subsequent ischemic myocardial damage. Although treatment with spasmogens altered aspects of plaque morphology, for example, endothelial protrusion and macrophage emigration, thrombosis was rare in these animals with chronic atherosclerotic disease.

Study of microdefects and their distribution in dislocation-free Si-doped HB GaAs by X-ray diffuse scattering on triple-crystal diffractometer

NASA Astrophysics Data System (ADS)

Charniy, L. A.; Morozov, A. N.; Bublik, V. T.; Scherbachev, K. D.; Stepantsova, I. V.; Kaganer, V. M.

1992-03-01

Microdefects in dislocation-free Si-doped (n = (1-3) × 10 18cm-3) HB GaAs crystals were studied by X-ray diffuse scattering measured with the help of a triple-crystal diffractometer. The intensity of the diffuse scattering as well as the isointensity contours around different reciprocal lattice points were analysed. A comparison of the measured isointensity contours with the theoretically calculated ones showed that the microdefects detected are interstitial dislocation loops with the Burgers vectors b = {1}/{2}<110 #3862;; lying in the planes #38;{110} and {111}. The mean radius of the dislocation loops R0 was determined using the wave vector q0 alpha; R-10 corresponding to the transmition point where the Huang diffuse scattering I( q) alpha q-2 ( q < q0) changed to the asymptotic scattering I( q) alpha q-4 ( q #62 q0). The analysis of a D-shaped cross-sectional (111) wafer cut from the end part of the HB ingot showed that R0 changed smoothly along the [ overline211] symmetry axis of the wafer. The highly inhomogeneous "new-moon"-like distribution of the non-dislocational etch-pits was also obtained. The maximal loop radius obtained at the edges of the wafer, R 0 = 1 μm, corresponds to the wafer area enriched with etch-pits and the minimal one, R 0 = 0.3 μm, corresponds to the bound of the new-moon-like area denuded from etch-pits. Microdefects of a new type were detected in the denuded area. These microdefects consist of nuclei, 0.1 μm in radius, and an extended atmosphere of interstitials. The minimal microdefect radius in the centre of the wafer corresponds to the maximum local value of the lattice parameter a = 5.655380 Å, and the minimum local value a = 5.65372 Å was obtained at the wafer edges enriched with microdefect-related etch-pits. Absolute X-ray diffuse intensity measurements were used for microdefect concentration determination. Normalization of I( q) was based on the comparison of the Huang intensity with the thermal diffuse scattering intensity which is predominant for the wave vector q å R-10. The microdefect concentration determined in this way appeared to be 4 × 10 9 cm -3 at the edges of the wafer and 4 × 10 11 cm -3 at the centre of the new-moon-like etch-pit denuded zone. The number of interstitial atoms forming dislocation loops is shown to be the same across the area of the wafer and equal to 10 16 cm -3.

Natural Variation in the Promoter of GSE5 Contributes to Grain Size Diversity in Rice.

PubMed

Duan, Penggen; Xu, Jinsong; Zeng, Dali; Zhang, Baolan; Geng, Mufan; Zhang, Guozheng; Huang, Ke; Huang, Luojiang; Xu, Ran; Ge, Song; Qian, Qian; Li, Yunhai

2017-05-01

The utilization of natural genetic variation greatly contributes to improvement of important agronomic traits in crops. Understanding the genetic basis for natural variation of grain size can help breeders develop high-yield rice varieties. In this study, we identify a previously unrecognized gene, named GSE5, in the qSW5/GW5 locus controlling rice grain size by combining the genome-wide association study with functional analyses. GSE5 encodes a plasma membrane-associated protein with IQ domains, which interacts with the rice calmodulin protein, OsCaM1-1. We found that loss of GSE5 function caused wide and heavy grains, while overexpression of GSE5 resulted in narrow grains. We showed that GSE5 regulates grain size predominantly by influencing cell proliferation in spikelet hulls. Three major haplotypes of GSE5 (GSE5, GSE5 DEL1+IN1 , and GSE5 DEL2 ) in cultivated rice were identified based on the deletion/insertion type in its promoter region. We demonstrated that a 950-bp deletion (DEL1) in indica varieties carrying the GSE5 DEL1+IN1 haplotype and a 1212-bp deletion (DEL2) in japonica varieties carrying the GSE5 DEL2 haplotype associated with decreased expression of GSE5, resulting in wide grains. Further analyses indicate that wild rice accessions contain all three haplotypes of GSE5, suggesting that the GSE5 haplotypes present in cultivated rice are likely to have originated from different wild rice accessions during rice domestication. Taken together, our results indicate that the previously unrecognized GSE5 gene in the qSW5/GW5 locus, which is widely utilized by rice breeders, controls grain size, and reveal that natural variation in the promoter region of GSE5 contributes to grain size diversity in rice. Copyright © 2017 The Author. Published by Elsevier Inc. All rights reserved.

Abundances, Ionization States, Temperatures, and FIP in Solar Energetic Particles

NASA Astrophysics Data System (ADS)

Reames, Donald V.

2018-04-01

The relative abundances of chemical elements and isotopes have been our most effective tool in identifying and understanding the physical processes that control populations of energetic particles. The early surprise in solar energetic particles (SEPs) was 1000-fold enhancements in {}3He/{}4He from resonant wave-particle interactions in the small "impulsive" SEP events that emit electron beams that produce type III radio bursts. Further studies found enhancements in Fe/O, then extreme enhancements in element abundances that increase with mass-to-charge ratio A/Q, rising by a factor of 1000 from He to Au or Pb arising in magnetic reconnection regions on open field lines in solar jets. In contrast, in the largest SEP events, the "gradual" events, acceleration occurs at shock waves driven out from the Sun by fast, wide coronal mass ejections (CMEs). Averaging many events provides a measure of solar coronal abundances, but A/Q-dependent scattering during transport causes variations with time; thus if Fe scatters less than O, Fe/O is enhanced early and depleted later. To complicate matters, shock waves often reaccelerate impulsive suprathermal ions left over or trapped above active regions that have spawned many impulsive events. Direct measurements of ionization states Q show coronal temperatures of 1-2 MK for most gradual events, but impulsive events often show stripping by matter traversal after acceleration. Direct measurements of Q are difficult and often unavailable. Since both impulsive and gradual SEP events have abundance enhancements that vary as powers of A/Q, we can use abundances to deduce the probable Q-values and the source plasma temperatures during acceleration, ≈3 MK for impulsive SEPs. This new technique also allows multiple spacecraft to measure temperature variations across the face of a shock wave, measurements otherwise unavailable and provides a new understanding of abundance variations in the element He. Comparing coronal abundances from SEPs and from the slow solar wind as a function of the first ionization potential (FIP) of the elements, remaining differences are for the elements C, P, and S. The theory of the fractionation of ions by Alfvén waves shows that C, P, and S are suppressed because of wave resonances during chromospheric transport on closed magnetic loops but not on open magnetic fields that supply the solar wind. Shock waves can accelerate ions from closed coronal loops that easily escape as SEPs, while the solar wind must emerge on open fields.

Effect of QiShenYiQi pill on myocardial collagen metabolism in experimental autoimmune myocarditis rats.

PubMed

Lv, Shi-Chao; Wu, Meifang; Li, Meng; Wang, Qiang; Wang, Xiao-Jing; Zhang, Ao; Xu, Ling; Zhang, Jun-Ping

2017-04-01

To observe the effect of QiShenYiQi pill (QSYQ) on myocardial collagen metabolism in experimental autoimmune myocarditis rats, and to explore its mechanism of action. Lewis rats underwent the injection of myocardial myosin mixed with freund's complete adjuvant were randomized into three groups: model, valsartan and QSYQ groups. And we treated rats which were injected phosphate buffered saline (PBS) mixed with freund's complete adjuvant as control group. Rats were intervened and euthanized at 4 and 8 weeks. We use alkaline hydrolysis to detect the content of myocardial hydroxyproline (HYP), and ELISA to detect the level of serum procollagen type I carboxyterminal peptide (PICP), procollagen type III amino-terminal peptide (PIIINP), and collagen C telopeptide type I (CTX-I). Myocardial MMP-1 and TIMP-1 protein expression was detected by immunohistochemistry, and myocardial MMP-1 and TIMP-1 mRNA expression was detected by real-time qPCR. QSYQ reduced the content of myocardial HYP, and this reduction was greater over time. QSYQ also reduced the serum concentration of PICP, PIIINP, CTX-I and the PICP/PIIINP ratio, which further reduced over time, whereas its effect on lowering PICP was significantly greater than that of valsartan at 4 and 8 weeks, and lowering CTX-I was significantly greater than that of valsartan at 8 weeks. In addition, after 4 weeks, QSYQ enhanced the protein and mRNA expression of MMP-1 and TIMP-1, and its effect on highering TIMP-1 was significantly greater than that of valsartan, whereas there was no significant difference in the expression of myocardial MMP-1 or TIMP-1 at 8 weeks. QSYQ reduced the ratio of MMP-1/TIMP-1, which further reduced over time, and the effect of QYSQ was significantly greater than that of valsartan after 4 weeks. This study provides evidence that QSYQ can reduce the rate of myocardial collagen synthesis and degradation. It also effectively improved the degree of myocardial fibrosis in experimental autoimmune myocarditis rats and it had a tendency to have a greater effect with longer treatment duration, which is related to the mechanism of regulation of MMP-1 and TIMP-1 expression in the myocardial rat. Copyright © 2017. Published by Elsevier Masson SAS.

A Study of the Irradiance- and Temperature-Dependence of Mid-Wave-Infrared (MWIR) Absorption in Indium Antimonide (InSb)

DTIC Science & Technology

2008-08-01

Direct valence to conduction band transitions (constant k vector ), (B) Indirect valence to conduction band transitions aided by photon/phonon coupling...feilddt g g dk dk dE dxdk qE dt dt v d v dt→ = = = − h h 1 (2.7) and g dx v dt = , which means that feild dk qE dt = −h . In order to find the...x B k xΨ = + where A and B are variables that are solved, kx is the wave vector and x is the distance. For a realistic solution, the wave function

Direct pair production in heavy-ion--atom collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anholt, R.; Jakubassa-Amundsen, D.H.; Amundsen, P.A.

1983-02-01

Direct pair production in approx.5-MeV/amu heavy-ion--atom collisions with uranium target atoms is calculated with the plane-wave Born approximation and the semiclassical approximation. Briggs's approximation is used to obtain the electron and positron wave functions. Since pair production involves high momentum transfer q from the moving projectile to the vacuum, use is made of a high-q approximation to greatly simplify the numerical computations. Coulomb deflection of the projectile, the effect of finite nuclear size on the elec- tronic wave functions, and the energy loss by the projectile exciting the pair are all taken into account in these calculations.

A Experimental Study of Fluctuating Pressure Loads Beneath Swept Shock Wave/boundary Layer Interactions

NASA Astrophysics Data System (ADS)

Garg, Sanjay

An experimental research program providing basic knowledge and establishing a database on the fluctuating pressure loads produced on aerodynamic surfaces beneath three-dimensional shock wave/boundary layer interactions is described. Such loads constitute a fundamental problem of critical concern to future supersonic and hypersonic flight vehicles. A turbulent boundary layer on a flat plate is subjected to interactions with swept planar shock waves generated by sharp fins. Fin angles from 10 ^circ to 20^circ at freestream Mach numbers of 3 and 4 produce a variety of interaction strengths from weak to very strong. Miniature pressure transducers flush-mounted in the flat plate have been used to measure interaction-induced wall pressure fluctuations. The distributions of properties of the pressure fluctuations, such as their rms level, amplitude distribution and power spectra, are also determined. Measurements have been made for the first time in the aft regions of these interactions, revealing fluctuating pressure levels as high as 155 dB, which places them in the category of significant aeroacoustic load generators. The fluctuations near the foot of the fin are dominated by low frequency (0-5 kHz) components, and are caused by a previously unrecognized random motion of the primary attachment line. This phenomenon is probably intimately linked to the unsteadiness of the separation shock at the start of the interaction. The characteristics of the pressure fluctuations are explained in light of the features of the interaction flowfield. In particular, physical mechanisms responsible for the generation of high levels of surface pressure fluctuations are proposed based on the results of the study. The unsteadiness of the flowfield of the surface is also examined via a novel, non-intrusive optical technique. Results show that the entire shock structure generated by the interaction undergoes relatively low-frequency oscillations.

Imaging of Myocardial Fatty Acid Oxidation

PubMed Central

Mather, Kieren J; DeGrado, Tim

2016-01-01

Myocardial fuel selection is a key feature of the health and function of the heart, with clear links between myocardial function and fuel selection and important impacts of fuel selection on ischemia tolerance. Radiopharmaceuticals provide uniquely valuable tools for in vivo, non-invasive assessment of these aspects of cardiac function and metabolism. Here we review the landscape of imaging probes developed to provide noninvasive assessment of myocardial fatty acid oxidation (MFAO). Also, we review the state of current knowledge that myocardial fatty acid imaging has helped establish of static and dynamic fuel selection that characterizes cardiac and cardiometabolic disease and the interplay between fuel selection and various aspects of cardiac function. PMID:26923433

The presence of enterovirus, adenovirus, and parvovirus B19 in myocardial tissue samples from autopsies: an evaluation of their frequencies in deceased individuals with myocarditis and in non-inflamed control hearts.

PubMed

Nielsen, Trine Skov; Hansen, Jakob; Nielsen, Lars Peter; Baandrup, Ulrik Thorngren; Banner, Jytte

2014-09-01

Multiple viruses have been detected in cardiac tissue, but their role in causing myocarditis remains controversial. Viral diagnostics are increasingly used in forensic medicine, but the interpretation of the results can sometimes be challenging. In this study, we examined the prevalence of adenovirus, enterovirus, and parvovirus B19 (PVB) in myocardial autopsy samples from myocarditis related deaths and in non-inflamed control hearts in an effort to clarify their significance as the causes of myocarditis in a forensic material. We collected all autopsy cases diagnosed with myocarditis from 1992 to 2010. Eighty-four suicidal deaths with morphologically normal hearts served as controls. Polymerase chain reaction was used for the detection of the viral genomes (adenovirus, enterovirus, and PVB) in myocardial tissue specimens. The distinction between acute and persistent PVB infection was made by the serological determination of PVB-specific immunoglobulins M and G. PVB was detected in 33 of 112 (29 %) myocarditis cases and 37 of 84 (44 %) control cases. All of the samples were negative for the presence of adenovirus and enterovirus. Serological evidence of an acute PVB infection, determined by the presence of immunoglobulin M, was only present in one case. In the remaining cases, PVB was considered to be a bystander with no or limited association to myocardial inflammation. In this study, adenovirus, enterovirus, and PVB were found to be rare causes of myocarditis. The detection of PVB in myocardial autopsy samples most likely represents a persistent infection with no or limited association with myocardial inflammation. The forensic investigation of myocardial inflammation demands a thorough examination, including special attention to non-viral causes and requires a multidisciplinary approach.

Non-contact detection of myocardium's mechanical activity by ultrawideband RF-radar and interpretation applying electrocardiography

NASA Astrophysics Data System (ADS)

Thiel, F.; Kreiseler, D.; Seifert, F.

2009-11-01

Electromagnetic waves can propagate through the body and are reflected at interfaces between materials with different dielectric properties. Therefore the reason for using ultrawideband (UWB) radar for probing the human body in the frequency range from 100 MHz up to 10 GHz is obvious and suggests an ability to monitor the motion of organs within the human body as well as obtaining images of internal structures. The specific advantages of UWB sensors are high temporal and spatial resolutions, penetration into object, low integral power, and compatibility with established narrowband systems. The sensitivity to ultralow power signals makes them suitable for human medical applications including mobile and continuous noncontact supervision of vital functions. Since no ionizing radiation is used, and due to the ultralow specific absorption rate applied, UWB techniques permit noninvasive sensing with no potential risks. This research aims at the synergetic use of UWB sounding combined with magnetic resonance imaging (MRI) to gain complementary information for improved functional diagnosis and imaging, especially to accelerate and enhance cardiac MRI by applying UWB radar as a noncontact navigator of myocardial contraction. To this end a sound understanding of how myocardial's mechanic is rendered by reflected and postprocessed UWB radar signals must be achieved. Therefore, we have executed the simultaneous acquisition and evaluation of radar signals with signals from a high-resolution electrocardiogram. The noncontact UWB illumination was done from several radiographic standard positions to monitor selected superficial myocardial areas during the cyclic physiological myocardial deformation in three different respiratory states. From our findings we could conclude that UWB radar can serve as a navigator technique for high and ultrahigh field magnetic resonance imaging and can be beneficial preserving the high resolution capability of this imaging modality. Furthermore it can potentially be used to support standard electrocardiography (ECG) analysis by complementary information where sole ECG analysis fails, e.g., electromechanical dissociation.

Non-contact detection of myocardium's mechanical activity by ultrawideband RF-radar and interpretation applying electrocardiography.

PubMed

Thiel, F; Kreiseler, D; Seifert, F

2009-11-01

Electromagnetic waves can propagate through the body and are reflected at interfaces between materials with different dielectric properties. Therefore the reason for using ultrawideband (UWB) radar for probing the human body in the frequency range from 100 MHz up to 10 GHz is obvious and suggests an ability to monitor the motion of organs within the human body as well as obtaining images of internal structures. The specific advantages of UWB sensors are high temporal and spatial resolutions, penetration into object, low integral power, and compatibility with established narrowband systems. The sensitivity to ultralow power signals makes them suitable for human medical applications including mobile and continuous noncontact supervision of vital functions. Since no ionizing radiation is used, and due to the ultralow specific absorption rate applied, UWB techniques permit noninvasive sensing with no potential risks. This research aims at the synergetic use of UWB sounding combined with magnetic resonance imaging (MRI) to gain complementary information for improved functional diagnosis and imaging, especially to accelerate and enhance cardiac MRI by applying UWB radar as a noncontact navigator of myocardial contraction. To this end a sound understanding of how myocardial's mechanic is rendered by reflected and postprocessed UWB radar signals must be achieved. Therefore, we have executed the simultaneous acquisition and evaluation of radar signals with signals from a high-resolution electrocardiogram. The noncontact UWB illumination was done from several radiographic standard positions to monitor selected superficial myocardial areas during the cyclic physiological myocardial deformation in three different respiratory states. From our findings we could conclude that UWB radar can serve as a navigator technique for high and ultrahigh field magnetic resonance imaging and can be beneficial preserving the high resolution capability of this imaging modality. Furthermore it can potentially be used to support standard electrocardiography (ECG) analysis by complementary information where sole ECG analysis fails, e.g., electromechanical dissociation.

Wave and pseudo-diffusion equations from squeezed states

NASA Technical Reports Server (NTRS)

Daboul, Jamil

1993-01-01

We show that the probability distributions P(sub n)(q,p;y) := the absolute value squared of (n(p,q;y), which are obtained from squeezed states, obey an interesting partial differential equation, to which we give two intuitive interpretations: as a wave equation in one space dimension; and as a pseudo-diffusion equation. We also study the corresponding Wehrl entropies S(sub n)(y), and we show that they have minima at zero squeezing, y = 0.

A model for attenuation and scattering in the Earth's crust

NASA Astrophysics Data System (ADS)

Toksöz, M. Nafi; Dainty, Anton M.; Reiter, Edmund; Wu, Ru-Shan

1988-03-01

The mechanisms contributing to the attenuation of earthquake ground motion in the distance range of 10 to 200 km are studied with the aid of laboratory data, coda waves Rg attenuation, strong motion attenuation measurements in the northeast United States and Canada, and theoretical models. The frequency range 1 10 Hz has been studied. The relative contributions to attenuation of anelasticity of crustal rocks (constant Q), fluid flow and scattering are evaluated. Scattering is found to be strong with an albedo B 0=0.8 0.9 and a scattering extinction length of 17 32 km. The albedo is defined as the ratio of the total extinction length to the scattering extinction length. The Rg results indicate that Q increases with depth in the upper kilometer or two of the crust, at least in New England. Coda Q appears to be equivalent to intrinsic (anelastic) Q and indicates that this Q increases with frequency as Q=Q o f n , where n is in the range of 0.2 0.9. The intrinsic attenuation in the crust can be explained by a high constant Q (500≤ Q o≤2000) and a frequency dependent mechanism most likely due to fluid effects in rocks and cracks. A fluid-flow attenuation model gives a frequency dependence ( Q≃ Q o f 0.5) similar to those determined from the analysis of coda waves of regional seismograms. Q is low near the surface and high in the body of the crust.

Long Non-Coding RNA H19 Protects H9c2 Cells against Hypoxia-Induced Injury by Targeting MicroRNA-139.

PubMed

Gong, Li-Cheng; Xu, Hai-Ming; Guo, Gong-Liang; Zhang, Tao; Shi, Jing-Wei; Chang, Chang

2017-01-01

Acute myocardial infarction (AMI) occurs when blood supply to the heart is diminished (ischemia) for long time; ischemia is primarily caused due to hypoxia. The present study evaluated the effects of long non-coding RNA H19 on hypoxic rat H9c2 cells and mouse HL-1 cells. Hypoxic injury was confirmed by measuring cell viability, migration and invasion, and apoptosis using MTT, Transwell and flow cytometry assays, respectively. H19 expression after hypoxia was estimated by qRT-PCR. We then measured the effects of non-physiologically expressed H19, knockdown of miR-139 with or without H19 silence, and abnormally expressed Sox8 on hypoxia-induced H9c2 cells. Moreover, the interacted miRNA for H19 and downstream target gene were virtually screened and verified. The involved signaling pathways and the effects of abnormally expressed H19 on contractility of HL-1 cells were explored via Western blot analysis. Hypoxia induced decreases of cell viability, migration and invasion, increase of cell apoptosis and up-regulation of H19. Knockdown of H19 increased hypoxia-induced injury in H9c2 cells. H19 acted as a sponge for miR-139 and H19 knockdown aggravated hypoxia-induced injury by up-regulating miR-139. Sox8 was identified as a target of miR-139, and its expression was negatively regulated by miR-139. The mechanistic studies revealed that overexpression of Sox8 might decrease hypoxia-induced cell injury by activating the PI3K/AKT/mTOR pathway and MAPK. Besides, H19 promoted contractility of HL-1 cells. These findings suggest that H19 alleviates hypoxia-induced myocardial cell injury by miR-139-mediated up-regulation of Sox8, along with activation of the PI3K/AKT/mTOR pathway and MAPK. © 2017 The Author(s). Published by S. Karger AG, Basel.

A Dislocation Model of Seismic Wave Attenuation and Micro-creep in the Earth: Harold Jeffreys and the Rheology of the Solid Earth

NASA Astrophysics Data System (ADS)

Karato, S.

A microphysical model of seismic wave attenuation is developed to provide a physical basis to interpret temperature and frequency dependence of seismic wave attenuation. The model is based on the dynamics of dislocation motion in minerals with a high Peierls stress. It is proposed that most of seismic wave attenuation occurs through the migration of geometrical kinks (micro-glide) and/or nucleation/migration of an isolated pair of kinks (Bordoni peak), whereas the long-term plastic deformation involves the continuing nucleation and migration of kinks (macro-glide). Kink migration is much easier than kink nucleation, and this provides a natural explanation for the vast difference in dislocation mobility between seismic and geological time scales. The frequency and temperature dependences of attenuation depend on the geometry and dynamics of dislocation motion both of which affect the distribution of relaxation times. The distribution of relaxation times is largely controlled by the distribution in distance between pinning points of dislocations, L, and the observed frequency dependence of Q, Q, Q ωα is shown to require a distribution function of P(L) L-m with m=4-2α The activation energy of Q-1 in minerals with a high Peierls stress corresponds to that for kink nucleation and is similar to that of long-term creep. The observed large lateral variation in Q-1 strongly suggests that the Q-1 in the mantle is frequency dependent. Micro-deformation with high dislocation mobility will (temporarily) cease when all the geometrical kinks are exhausted. For a typical dislocation density of 108 m-2, transient creep with small viscosity related to seismic wave attenuation will persist up to the strain of 10-6, thus even a small strain ( 10-6-10-4) process such as post-glacial rebound is only marginally affected by this type of anelastic relaxation. At longer time scales continuing nucleation of kinks becomes important and enables indefinitely large strain, steady-state creep, causing viscous behavior.

Derivation of Hamaker Dispersion Energy of Amorphous Carbon Surfaces in Contact with Liquids Using Photoelectron Energy-Loss Spectra

NASA Astrophysics Data System (ADS)

Godet, Christian; David, Denis

2017-12-01

Hamaker interaction energies and cutoff distances have been calculated for disordered carbon films, in contact with purely dispersive (diiodomethane) or polar (water) liquids, using their experimental dielectric functions ɛ ( q, ω) obtained over a broad energy range. In contrast with previous works, a q-averaged < ɛ ( q, ω) > q is derived from photoelectron energy-loss spectroscopy (XPS-PEELS) where the energy loss function (ELF) < Im[-1/ ɛ ( q, ω)] > q is a weighted average over allowed transferred wave vector values, q, given by the physics of bulk plasmon excitation. For microcrystalline diamond and amorphous carbon films with a wide range of (sp3/sp2 + sp3) hybridization, non-retarded Hamaker energies, A 132 ( L < 1 nm), were calculated in several configurations, and distance and wavenumber cutoff values were then calculated based on A 132 and the dispersive work of adhesion obtained from contact angles. A geometric average approximation, H 0 CVL = ( H 0 CVC H 0 LVL )1/2, holds for the cutoff separation distances obtained for carbon-vacuum-liquid (CVL), carbon-vacuum-carbon (CVC) and liquid-vacuum-liquid (LVL) equilibrium configurations. The linear dependence found for A CVL, A CLC and A CLV values as a function of A CVC, for each liquid, allows predictive relationships for Hamaker energies (in any configuration) using experimental determination of the dispersive component of the surface tension, {γ}_{CV}^d , and a guess value of the cutoff distance H 0 CVC of the solid. [Figure not available: see fulltext.

Testing the Ginzburg-Landau approximation for three-flavor crystalline color superconductivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mannarelli, Massimo; Sharma, Rishi; Rajagopal, Krishna

2006-06-01

It is an open challenge to analyze the crystalline color superconducting phases that may arise in cold dense, but not asymptotically dense, three-flavor quark matter. At present the only approximation within which it seems possible to compare the free energies of the myriad possible crystal structures is the Ginzburg-Landau approximation. Here, we test this approximation on a particularly simple 'crystal' structure in which there are only two condensates {approx}{delta}exp(iq{sub 2}{center_dot}r) and {approx}{delta}exp(iq{sub 3}{center_dot}r) whose position-space dependence is that of two plane waves with wave vectors q{sub 2} and q{sub 3} at arbitrary angles. For this case, we are able tomore » solve the mean-field gap equation without making a Ginzburg-Landau approximation. We find that the Ginzburg-Landau approximation works in the {delta}{yields}0 limit as expected, find that it correctly predicts that {delta} decreases with increasing angle between q{sub 2} and q{sub 3} meaning that the phase with q{sub 2} parallel q{sub 3} has the lowest free energy, and find that the Ginzburg-Landau approximation is conservative in the sense that it underestimates {delta} at all values of the angle between q{sub 2} and q{sub 3}.« less

Estimation of the intrinsic absorption and scattering attenuation in Northeastern Venezuela (Southeastern Caribbean) using coda waves

USGS Publications Warehouse

Ugalde, A.; Pujades, L.G.; Canas, J.A.; Villasenor, A.

1998-01-01

Northeastern Venezuela has been studied in terms of coda wave attenuation using seismograms from local earthquakes recorded by a temporary short-period seismic network. The studied area has been separated into two subregions in order to investigate lateral variations in the attenuation parameters. Coda-Q-1 (Q(c)-1) has been obtained using the single-scattering theory. The contribution of the intrinsic absorption (Q(i)-1) and scattering (Q(s)-1) to total attenuation (Q(t)-1) has been estimated by means of a multiple lapse time window method, based on the hypothesis of multiple isotropic scattering with uniform distribution of scatterers. Results show significant spatial variations of attenuation: the estimates for intermediate depth events and for shallow events present major differences. This fact may be related to different tectonic characteristics that may be due to the presence of the Lesser Antilles subduction zone, because the intermediate depth seismic zone may be coincident with the southern continuation of the subducting slab under the arc.

Frequency and Wavevector Dependence of the Atomic Level Stress-Stress Correlation Function in a Model Supercooled Liquid

NASA Astrophysics Data System (ADS)

Levashov, Valentin A.; Morris, James R.; Egami, Takeshi

2012-02-01

Temporal and spatial correlations among the local atomic level shear stresses were studied for a model liquid iron by molecular dynamics simulation [PRL 106,115703]. Integration over time and space of the shear stress correlation function F(r,t) yields viscosity via Green-Kubo relation. The stress correlation function in time and space F(r,t) was Fourier transformed to study the dependence on frequency, E, and wave vector, Q. The results, F(Q,E), showed damped shear stress waves propagating in the liquid for small Q at high and low temperatures. We also observed additional diffuse feature that appears as temperature is reduced below crossover temperature of potential energy landscape at relatively low frequencies at small Q. We suggest that this additional feature might be related to dynamic heterogeneity and boson peaks. We also discuss a relation between the time-scale of the stress-stress correlation function and the alpha-relaxation time of the intermediate self-scattering function S(Q,E).

Near-source attenuation of high-frequency body waves beneath the New Madrid Seismic Zone

NASA Astrophysics Data System (ADS)

Pezeshk, Shahram; Sedaghati, Farhad; Nazemi, Nima

2018-03-01

Attenuation characteristics in the New Madrid Seismic Zone (NMSZ) are estimated from 157 local seismograph recordings out of 46 earthquakes of 2.6 ≤ M ≤ 4.1 with hypocentral distances up to 60 km and focal depths down to 25 km. Digital waveform seismograms were obtained from local earthquakes in the NMSZ recorded by the Center for Earthquake Research and Information (CERI) at the University of Memphis. Using the coda normalization method, we tried to determine Q values and geometrical spreading exponents at 13 center frequencies. The scatter of the data and trade-off between the geometrical spreading and the quality factor did not allow us to simultaneously derive both these parameters from inversion. Assuming 1/ R 1.0 as the geometrical spreading function in the NMSZ, the Q P and Q S estimates increase with increasing frequency from 354 and 426 at 4 Hz to 729 and 1091 at 24 Hz, respectively. Fitting a power law equation to the Q estimates, we found the attenuation models for the P waves and S waves in the frequency range of 4 to 24 Hz as Q P = (115.80 ± 1.36) f (0.495 ± 0.129) and Q S = (161.34 ± 1.73) f (0.613 ± 0.067), respectively. We did not consider Q estimates from the coda normalization method for frequencies less than 4 Hz in the regression analysis since the decay of coda amplitude was not observed at most bandpass filtered seismograms for these frequencies. Q S/ Q P > 1, for 4 ≤ f ≤ 24 Hz as well as strong intrinsic attenuation, suggest that the crust beneath the NMSZ is partially fluid-saturated. Further, high scattering attenuation indicates the presence of a high level of small-scale heterogeneities inside the crust in this region.

Non-arrhythmic therapy of ventricular tachyarrhythmias and sudden cardiac death after acute myocardial infarction.

PubMed

Schweitzer, P

2006-12-01

The management of ventricular tachyarrhythmias and prevention of sudden cardiac death after acute myocardial infarction (AMI) underwent important evolution. In the CAST study, encanaide and other antiarrhythmic drugs were not only ineffective but also increased mortality after myocardial infarction. Amiodarone had some beneficial effect on arrhythmic events without improving survival, and ICDs failed to improve outcome early after AMI. In comparison, short and long term survival benefits of beta blockers, angiotensine converting enzyme inhibitors and aldosterone antagonists after AMI is well established. This review discusses the role of non-arrhythmic therapy in the prevention of ventricular tachyarrhythmia's and sudden cardiac death after AMI.

Diode-pumped continuous wave tunable and graphene Q-switched Tm:LSO lasers.

PubMed

Feng, T L; Zhao, S Z; Yang, K J; Li, G Q; Li, D C; Zhao, J; Qiao, W C; Hou, J; Yang, Y; He, J L; Zheng, L H; Wang, Q G; Xu, X D; Su, L B; Xu, J

2013-10-21

We have investigated the lasing characteristics of Tm:LSO crystal in three operation regimes: continuous wave (CW), wavelength tunable and passive Q-switching based on graphene. In CW regime, a maximum output power of 0.65 W at 2054.9 nm with a slope efficiency of 21% was achieved. With a quartz plate, a broad wavelength tunable range of 145 nm was obtained, corresponding to a FWHM of 100 nm. By using a graphene saturable absorber mirror, the passively Q-switched Tm:LSO laser produced pulses with duration of 7.8 μs at 2030.8 nm under a repetition rate of 7.6 kHz, corresponding to pulse energy of 14.0 μJ.

Efficient Q-switched Tm:YAG ceramic slab laser.

PubMed

Zhang, Shuaiyi; Wang, Mingjian; Xu, Lin; Wang, Yan; Tang, Yulong; Cheng, Xiaojin; Chen, Weibiao; Xu, Jianqiu; Jiang, Benxue; Pan, Yubai

2011-01-17

Characteristics of Tm:YAG ceramic for high efficient 2-μm lasers are analyzed. Efficient diode end-pumped continuous-wave and Q-switched Tm:YAG ceramic lasers are demonstrated. At the absorbed pump power of 53.2W, the maximum continuous wave (cw) output power of 17.2 W around 2016 nm was obtained with the output transmission of 5%. The optical conversion efficiency is 32.3%, corresponding to a slope efficiency of 36.5%. For Q-switched operation, the shortest width of 69 ns was achieved with the pulse repetition frequency of 500 Hz and single pulse energy of 20.4 mJ, which indicates excellent energy storage capability of the Tm:YAG ceramic.

miR-22-5p revealed as a potential biomarker involved in the acute phase of myocardial infarction via profiling of circulating microRNAs.

PubMed

Maciejak, Agata; Kiliszek, Marek; Opolski, Grzegorz; Segiet, Agnieszka; Matlak, Krzysztof; Dobrzycki, Slawomir; Tulacz, Dorota; Sygitowicz, Grazyna; Burzynska, Beata; Gora, Monika

2016-09-01

Acute myocardial infarction (AMI) is a life-threatening episode of coronary artery disease. Recently, circulating myocardial-derived microRNAs (miRNAs) have been reported as potential biomarkers of infarction. The present study aimed to identify differentially expressed miRNAs in patients with ST-segment elevation myocardial infarction that could be potentially dysregulated in response to early myocardial damage. miRNA expression profile analysis was performed using the Serum/Plasma Focus miRNA Polymerase Chain Reaction (PCR) panel of Exiqon A/S (Vedbaek, Denmark) on plasma samples of patients on the first day of AMI (admission) and on samples from the identical patients collected six months following AMI. Selected miRNAs were validated by reverse transcription‑quantitative PCR (RT‑qPCR) using independent patients with AMI and a control group of patients with a stable coronary artery disease. Thirty‑two species of plasma miRNA were differentially expressed (P<0.05) on admission compared with six months following AMI. Subsequent validation in an independent patient group confirmed that miR‑133b and miR‑22‑5p were significantly up‑regulated in the serum of patients with AMI. The receiver operating characteristic (ROC) curve analysis demonstrated a diagnostic utility for miR-22-5p, which has not previously been reported to be associated with AMI. Among the selected miRNAs, miR‑22‑5p represents a novel promising biomarker for the diagnosis of AMI.

[Effect of temperature on the structure of CaO-MgO-Al2O3-SiO2 nanocrystalline glass-ceramics studied by Raman spectroscopy].

PubMed

Li, Bao-Wei; Ouyang, Shun-Li; Zhang, Xue-Feng; Jia, Xiao-Lin; Deng, Lei-Bo; Liu, Fang

2014-07-01

In the present paper, nanocrystalline glass-ceramic of CaO-MgO-Al2O3-SiO2 system was produced by melting method. The CaO-MgO-Al2O3-SiO2 nanocrystalline glass-ceramic was measured by Raman spectroscopy in the temperature range from -190 to 310 degrees C in order to study the effect of temperature on the structure of this system nanocrystalline glass-ceramics. The results showed that different non-bridge oxygen bond silicon-oxygen tetrahedron structural unit changes are not consistent with rising temperature. Further analyses indicated that: the SiO4 tetrahedron with 2 non-bridged oxygen (Q2), the SiO4 tetrahedron with 3 non-bridged oxygen (Q(1)), which are situated at the edge of the 3-D SiO4 tetrahedrons network, and the SiO4 tetrahedron with 4 non-bridged oxygen (Q(0)), which is situated outside the 3-D network all suffered a significant influence by the temperature change, which has been expressed as: shifts towards the high wave-number, increased bond force constants, and shortened bond lengths. This paper studied the influence of temperature on CMAS system nanocrystalline glass-ceramics using variable temperature Raman technology. It provides experiment basis to the research on external environment influence on CMAS system nanocrystalline glass-ceramics materials in terms of structure and performance. In addition, the research provides experimental basis for controlling the expansion coefficient of nanocrystalline glass-ceramic of CaO-MgO-Al2O3-SiO2 system.

T-wave alternans negative coronary patients with low ejection and benefit from defibrillator implantation

NASA Technical Reports Server (NTRS)

Hohnloser, S. H.; Ikeda, T.; Bloomfield, D. M.; Dabbous, O. H.; Cohen, R. J.

2003-01-01

In a trial of prophylactic implantation of a defibrillator, a mortality benefit was seen among patients with previous myocardial infarction and a left-ventricular ejection fraction of 0.30 or less. We identified 129 similar patients from two previously published clinical trials in which microvolt T-wave alternans testing was prospectively assessed. At 24 months of follow-up, no sudden cardiac death or cardiac arrest was seen among patients who tested T-wave alternans negative, compared with an event rate of 15.6% among the remaining patients. Testing of T-wave alternans seems to identify patients who are at low risk of ventricular tachyarrhythmic event and who may not benefit from defibrillator therapy.

Q estimation of seismic data using the generalized S-transform

NASA Astrophysics Data System (ADS)

Hao, Yaju; Wen, Xiaotao; Zhang, Bo; He, Zhenhua; Zhang, Rui; Zhang, Jinming

2016-12-01

Quality factor, Q, is a parameter that characterizes the energy dissipation during seismic wave propagation. The reservoir pore is one of the main factors that affect the value of Q. Especially, when pore space is filled with oil or gas, the rock usually exhibits a relative low Q value. Such a low Q value has been used as a direct hydrocarbon indicator by many researchers. The conventional Q estimation method based on spectral ratio suffers from the problem of waveform tuning; hence, many researchers have introduced time-frequency analysis techniques to tackle this problem. Unfortunately, the window functions adopted in time-frequency analysis algorithms such as continuous wavelet transform (CWT) and S-transform (ST) contaminate the amplitude spectra because the seismic signal is multiplied by the window functions during time-frequency decomposition. The basic assumption of the spectral ratio method is that there is a linear relationship between natural logarithmic spectral ratio and frequency. However, this assumption does not hold if we take the influence of window functions into consideration. In this paper, we first employ a recently developed two-parameter generalized S-transform (GST) to obtain the time-frequency spectra of seismic traces. We then deduce the non-linear relationship between natural logarithmic spectral ratio and frequency. Finally, we obtain a linear relationship between natural logarithmic spectral ratio and a newly defined parameter γ by ignoring the negligible second order term. The gradient of this linear relationship is 1/Q. Here, the parameter γ is a function of frequency and source wavelet. Numerical examples for VSP and post-stack reflection data confirm that our algorithm is capable of yielding accurate results. The Q-value results estimated from field data acquired in western China show reasonable comparison with oil-producing well location.

Intrinsic and scattering attenuation of high-frequency S-waves in the central part of the External Dinarides

NASA Astrophysics Data System (ADS)

Majstorović, Josipa; Belinić, Tena; Namjesnik, Dalija; Dasović, Iva; Herak, Davorka; Herak, Marijan

2017-09-01

The central part of the External Dinarides (CED) is a geologically and tectonically complex region formed in the collision between the Adriatic microplate and the European plate. In this study, the contributions of intrinsic and scattering attenuation ( Q i - 1 and Q sc - 1 , respectively) to the total S-wave attenuation were calculated for the first time. The multiple lapse-time window analysis (MLTWA method), based on the assumptions of multiple isotropic scattering in a homogeneous medium with uniformly distributed scatterers, was applied to seismograms of 450 earthquakes recorded at six seismic stations. Selected events have hypocentral distances between 40 and 90 km with local magnitudes between 1.5 and 4.7. The analysis was performed over 11 frequency bands with central frequencies between 1.5 and 16 Hz. Results show that the seismic albedo of the studied area is less than 0.5 and Q i - 1 > Q sc - 1 at all central frequencies and for all stations. These imply that the intrinsic attenuation dominates over scattering attenuation in the whole study area. Calculated total S-wave and expected coda wave attenuation for CED are in a very good agreement with the ones measured in previous studies using the coda normalization and the coda-Q methods. All estimated attenuation factors decrease with increasing frequency. The intrinsic attenuation for CED is among the highest observed elsewhere, which could be due to the highly fractured and fluid-filled carbonates in the upper crust. The scattering and the total S-wave attenuation for CED are close to the average values obtained in other studies performed worldwide. In particular, good agreement of frequency dependence of total attenuation in CED and in the regions that contributed most strong-motion records for ground motion prediction equations used in PSHA in Croatia indicates that those were well chosen and applicable to this area as far as their attenuation properties are concerned.

Rationally engineered Troponin C modulates in vivo cardiac function and performance in health and disease.

PubMed

Shettigar, Vikram; Zhang, Bo; Little, Sean C; Salhi, Hussam E; Hansen, Brian J; Li, Ning; Zhang, Jianchao; Roof, Steve R; Ho, Hsiang-Ting; Brunello, Lucia; Lerch, Jessica K; Weisleder, Noah; Fedorov, Vadim V; Accornero, Federica; Rafael-Fortney, Jill A; Gyorke, Sandor; Janssen, Paul M L; Biesiadecki, Brandon J; Ziolo, Mark T; Davis, Jonathan P

2016-02-24

Treatment for heart disease, the leading cause of death in the world, has progressed little for several decades. Here we develop a protein engineering approach to directly tune in vivo cardiac contractility by tailoring the ability of the heart to respond to the Ca(2+) signal. Promisingly, our smartly formulated Ca(2+)-sensitizing TnC (L48Q) enhances heart function without any adverse effects that are commonly observed with positive inotropes. In a myocardial infarction (MI) model of heart failure, expression of TnC L48Q before the MI preserves cardiac function and performance. Moreover, expression of TnC L48Q after the MI therapeutically enhances cardiac function and performance, without compromising survival. We demonstrate engineering TnC can specifically and precisely modulate cardiac contractility that when combined with gene therapy can be employed as a therapeutic strategy for heart disease.

Rationally engineered Troponin C modulates in vivo cardiac function and performance in health and disease

PubMed Central

Shettigar, Vikram; Zhang, Bo; Little, Sean C.; Salhi, Hussam E.; Hansen, Brian J.; Li, Ning; Zhang, Jianchao; Roof, Steve R.; Ho, Hsiang-Ting; Brunello, Lucia; Lerch, Jessica K.; Weisleder, Noah; Fedorov, Vadim V.; Accornero, Federica; Rafael-Fortney, Jill A.; Gyorke, Sandor; Janssen, Paul M. L.; Biesiadecki, Brandon J.; Ziolo, Mark T.; Davis, Jonathan P.

2016-01-01

Treatment for heart disease, the leading cause of death in the world, has progressed little for several decades. Here we develop a protein engineering approach to directly tune in vivo cardiac contractility by tailoring the ability of the heart to respond to the Ca2+ signal. Promisingly, our smartly formulated Ca2+-sensitizing TnC (L48Q) enhances heart function without any adverse effects that are commonly observed with positive inotropes. In a myocardial infarction (MI) model of heart failure, expression of TnC L48Q before the MI preserves cardiac function and performance. Moreover, expression of TnC L48Q after the MI therapeutically enhances cardiac function and performance, without compromising survival. We demonstrate engineering TnC can specifically and precisely modulate cardiac contractility that when combined with gene therapy can be employed as a therapeutic strategy for heart disease. PMID:26908229

Comparison of the efficacy of pharmacoinvasive management for ST-segment elevation myocardial infarction in smokers versus non-smokers (from the Trial of Routine Angioplasty and Stenting After Fibrinolysis to Enhance Reperfusion in Acute Myocardial Infarction).

PubMed

Tan, Nigel S; Goodman, Shaun G; Cantor, Warren J; Tan, Mary K; Yan, Raymond T; Bagnall, Alan J; Mehta, Shamir R; Fitchett, David; Strauss, Bradley H; Yan, Andrew T

2014-10-01

Compared with non-smokers, cigarette smokers with ST-segment elevation myocardial infarctions derive greater benefit from fibrinolytic therapy. However, it is not known whether the optimal treatment strategy after fibrinolysis differs on the basis of smoking status. The Trial of Routine Angioplasty and Stenting After Fibrinolysis to Enhance Reperfusion in Acute Myocardial Infarction (TRANSFER-AMI) randomized patients with ST-segment elevation myocardial infarctions to a routine early invasive (pharmacoinvasive) versus a standard (early transfer only for rescue percutaneous coronary intervention or delayed angiography) strategy after fibrinolysis. The efficacy of these strategies was compared in 1,051 patients on the basis of their smoking status. Treatment heterogeneity was assessed between smokers and non-smokers, and multivariable analysis was performed to evaluate for an interaction between smoking status and treatment strategy after adjusting for baseline Global Registry of Acute Coronary Events (GRACE) risk score. Smokers (n=448) were younger, had fewer cardiovascular risk factors, and had lower GRACE risk scores. They had a lower rate of the primary composite end point of 30-day mortality, reinfarction, recurrent ischemia, heart failure, or cardiogenic shock and fewer deaths or reinfarctions at 6 months and 1 year. Smoking status was not a significant predictor of either primary or secondary end points in multivariable analysis. Pharmacoinvasive management reduced the primary end point compared with standard therapy in smokers (7.7% vs 13.6%, p=0.04) and non-smokers (13.1% vs 19.7%, p=0.03). Smoking status did not modify treatment effect on any measured outcomes (p>0.10 for all). In conclusion, compared with non-smokers, current smokers receiving either standard or early invasive management of ST-segment elevation myocardial infarction after fibrinolysis have more favorable outcomes, which is likely attributable to their better baseline risk profile. The beneficial treatment effect of a pharmacoinvasive strategy is consistent in smokers and non-smokers. Copyright © 2014 Elsevier Inc. All rights reserved.

Traces of charge density waves in NbS2

NASA Astrophysics Data System (ADS)

Leroux, Maxime; Cario, Laurent; Bosak, Alexei; Rodière, Pierre

2018-05-01

Among transition metal dichalcogenides (TMD), NbS2 is often considered as the archetypal compound that does not have a charge density wave (CDW) in any of its polytypes. By comparison, close isoelectronic compounds such as NbSe2, TaS2, and TaSe2 all have CDW in at least one polytype. Here we report traces of CDW in the 2H polytype of NbS2, using diffuse x-ray scattering measurements at 77 K and room temperature. We observe 12 extremely weak satellite peaks located at ±13.9° from a⃗* and b⃗* around each Bragg peak in the (h ,k ,0 ) plane. These satellite peaks are commensurate with the lattice via 3 q ⃗-q ⃗'=a⃗*,where q ⃗' is the 120° rotation of q ⃗, and define two √{13 }a ×√{13 }a superlattices in real space. These commensurate wave vectors and tilt angle are identical to those of the CDW observed in the 1T polytype of TaS2 and TaSe2. To understand this similarity and the faintness of the peaks, we discuss possible sources of local 1T polytype environment in bulk 2H-NbS2 crystals.

Near surface velocity and Q S structure of the Quaternary sediment in Bohai basin, China

NASA Astrophysics Data System (ADS)

Chong, Jiajun; Ni, Sidao

2009-10-01

Heavily populated by Beijing and Tianjin cities, Bohai basin is a seismically active Cenozoic basin suffering from huge lost by devastating earthquakes, such as Tangshan earthquake. The attenuation ( Q P and Q S) of the surficial Quaternary sediment has not been studied at natural seismic frequency (1-10 Hz), which is crucial to earthquake hazards study. Borehole seismic records of micro earthquake provide us a good way to study the velocity and attenuation of the surficial structure (0-500 m). We found that there are two pulses well separated with simple waveforms on borehole seismic records from the 2006 M W4.9 Wen’an earthquake sequence. Then we performed waveform modeling with generalized ray theory (GRT) to confirm that the two pulses are direct wave and surface reflected wave, and found that the average ν P and ν S of the top 300 m in this region are about 1.8 km/s and 0.42 km/s, leading to high ν P/ ν S ratio of 4.3. We also modeled surface reflected wave with propagating matrix method to constrain Q S and the near surface velocity structure. Our modeling indicates that Q S is at least 30, or probably up to 100, much larger than the typically assumed extremely low Q (˜10), but consistent with Q S modeling in Mississippi embayment. Also, the velocity gradient just beneath the free surface (0-50 m) is very large and velocity increases gradually at larger depth. Our modeling demonstrates the importance of borehole seismic records in resolving shallow velocity and attenuation structure, and hence may help in earthquake hazard simulation.

[Extracorporeal cardiac shock wave therapy for treatment of coronary artery disease].

PubMed

Wang, Yu; Guo, Tao; Cai, Hong-Yan; Ma, Tie-Kun; Tao, Si-Ming; Chen, Ming-Qing; Gu, Yun; Pan, Jia-Hua; Xiao, Jian-Ming; Zhao, Ling; Yang, Xi-Yun; Yang, Chao

2010-08-01

To evaluate the feasibility and efficiency of extracorporeal cardiac shock wave therapy (CSWT) for treatment of coronary artery disease. Twenty-five patients with 1 - 16 years history of chronic angina pectoris underwent the CSWT. Before and after the treatment, low-dose Dobutamine stress echocardiography and (99)Tc(m)-MIBI myocardial perfusion SPECT were applied to locate the ischemic segments, detect the viable myocardium and evaluate the effect of CSWT. Under the guidance of echocardiography, CSWT was applied in R-wave-triggered manner with low energy (0.09 mJ/mm(2)) at 200 shoots/spot for 9 spots (-1-0-+1 combination). Patients were divided group A and group B. Sixteen patients in group A were applied 9 sessions on 29 segments within 3 month and nine patients in group B were applied 9 sessions on 13 segments within 1 month. Ten chronic angina pectoris patients receiving standard medication served as controls. All patients completed the 9 sessions without procedural complications or adverse effects. CSWT significantly improved symptoms as evaluated by NYHA, Canadian Cardiovascular Society (CCS) class sores, Seattle angina questionnaire (SAQ), 6-min walk and the use of nitroglycerin (P < 0.05). CSWT also improved myocardial perfusion and regional myocardium function as evaluated by rest SPECT and stress peak systolic strain rate (PSSR) (P < 0.01). Myocardial perfusion improvement was more significant in group A compared with group B (1.21 ± 0.86 vs. 0.83 ± 0.80, P < 0.01). All parameters remained unchanged in control group during follow up. These preliminary results indicate that CSWT is safe and effective on ameliorating anginal symptoms for chronic angina pectoris patients.

Value of normal electrocardiographic findings in predicting resting left ventricular function in patients with chest pain and suspected coronary artery disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Keefe, J.H. Jr.; Zinsmeister, A.R.; Gibbons, R.J.

1989-06-01

Characterization of left ventricular function is important in managing patients with coronary artery disease. Although many methods are available to assess left ventricular function, most are either expensive, invasive, or both. In this study, we examined the ability of normal or near-normal resting electrocardiographic findings to predict resting left ventricular ejection fraction, measured by resting radionuclide angiography, in 874 patients with chest pain and suspected coronary artery disease. A retrospective review was undertaken of 4,410 Mayo Clinic patients who underwent rest and exercise radionuclide ventriculography for the evaluation of chest pain and known or suspected coronary artery disease; of these,more » 874 patients met the inclusion criteria for the current study. A 15-lead electrocardiogram, which was interpreted by the cardiologist or cardiology trainee working in the laboratory, was obtained at the same evaluation as the radionuclide study. In 590 patients with no previous history of a myocardial infarction and entirely normal resting electrocardiographic results without nonspecific ST-T wave abnormalities, the mean left ventricular ejection fraction was 0.63 +/- 0.004, and 559 patients (95%) had a normal resting ejection fraction (defined as 0.50 or more). Both nonspecific ST-T wave abnormalities (p less than 0.001) and, to a lesser degree, a history of myocardial infarction (p = 0.06) were independent predictors of an abnormal resting ejection fraction. In 185 patients with nonspecific ST-T wave abnormalities and no history of myocardial infarction, the mean left ventricular ejection fraction was 0.61 +/- 0.009, and 85% had a normal resting ejection fraction.« less

Analytical Investigations of Bulk Wave Resonators in the Piezoelectric Thin Film on Gallium-Arsenide Configuration.

DTIC Science & Technology

1987-07-28

OPPICE SYMBOL (Inedu @ Ame Cadep Kevin J. Malloy 202-767-4931 NE DO FORM 1473, 83 APR EDITION OF I JAN 73 S OBSOLETE. Unclassified . ’ J P...Sitnce thle calculated Q is a very cuadshldbhiertnteatalQsbcuete rapdlyvaringfuntioi o th waer hicnes, clcuatins material Q and thle Q due to radiation

Managing health habits for myocardial infarction (MI) patients.

PubMed

Song, R; Lee, H

2001-08-01

The study examined effects of the heart camp as a motivation enhancement program on cardiac risk reduction and behavioral modification in myocardial infarction (MI) patients. A total of 86 outpatients participated at the first heart camp and 45 returned to the second one in 8 weeks. The first and second heart camps were daylong programs consisted of health assessment, education classes, and Q&A session with interdisciplinary team approach. At the completion of the heart camp, the participants showed significantly lower scores in cardiac risk factors, and significant improvements in motivational variables, especially, perceived benefits and perceived barriers as well as in the performance of diet and exercise behaviors. The study results confirm that it is possible to enhance motivation for chronic patients like MI patients by even short period of comprehensive educational program.

C1q Deficiency Promotes Pulmonary Vascular Inflammation and Enhances the Susceptibility of the Lung Endothelium to Injury*

PubMed Central

Shah, Dilip; Romero, Freddy; Zhu, Ying; Duong, Michelle; Sun, Jianxin; Walsh, Kenneth; Summer, Ross

2015-01-01

The collectin proteins are innate immune molecules found in high concentrations on the epithelial and endothelial surfaces of the lung. While these proteins are known to have important anti-inflammatory actions in the airways of the lung little is known of their functional importance in the pulmonary circulation. We recently demonstrated that the circulating collectin protein adiponectin has potent anti-inflammatory effects on the lung endothelium, leading us to reason that other structurally related proteins might have similar effects. To test this hypothesis, we investigated the anti-inflammatory actions of C1q in lung endothelial homeostasis and the pulmonary vascular response to LPS or HCl injury. We show that lung endothelium from C1q-deficient (C1q−/−) mice expresses higher baseline levels of the vascular adhesion markers ICAM-1, VCAM-1, and E-selectin when compared with wild-type mice. Further, we demonstrate that these changes are associated with enhanced susceptibility of the lung to injury as evident by increased expression of adhesion markers, enhanced production of pro-inflammatory cytokines, and augmented neutrophil recruitment. Additionally, we found that C1q−/− mice also exhibited enhanced endothelial barrier dysfunction after injury as manifested by decreased expression of junctional adherens proteins and enhanced vascular leakage. Mechanistically, C1q appears to mediate its effects by inhibiting phosphorylation of p38 mitogen-activated protein kinase (MAPK) and blocking nuclear translocation of the P65 subunit of nuclear factor (NF)-κB. In summary, our findings indicate a previously unrecognized role for C1q in pulmonary vascular homeostasis and provide added support for the hypothesis that circulating collectin proteins have protective effects on the lung endothelium. PMID:26487714

Coronary Catheterization Laboratory Role for Post-Resuscitation Care Without ST Elevation Myocardial Infarction.

PubMed

Kumar, Kris; Lotun, Kapildeo

2018-05-07

Out of hospital cardiac arrest management of patients with non-ST myocardial infarction per current American Heart Association and European Resuscitation Council guidelines leave the decision in regard to early angiography up to the physician operators. Guidelines are clear on the positive impact of early intervention on survival and improvement on left ventricular function in patients presenting with cardiac arrest and ST elevation myocardial infarction on electrocardiogram. This review aims to analyze the data that current guidelines are based upon in regards to out of hospital cardiac arrest with electrocardiogram findings of non-ST elevation myocardial infarction as well as other clinical trials that support early angiography and reperfusion strategies as well as future studies that are in trial to study the role of the coronary catheterization laboratory in cardiac arrest. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Myocardial and Peripheral Ischemia Causes an Increase in Circulating Pregnancy-Associated Plasma Protein-A in Non-atherosclerotic, Non-heparinized Pigs.

PubMed

Steffensen, Lasse Bach; Poulsen, Christian Bo; Shim, Jeong; Bek, Marie; Jacobsen, Kevin; Conover, Cheryl A; Bentzon, Jacob Fog; Oxvig, Claus

2015-12-01

The usefulness of circulating pregnancy-associated plasma protein-A (PAPP-A) as a biomarker for acute coronary syndrome (ACS) is widely debated. We used the pig as a model to assess PAPP-A dynamics in the setting of myocardial ischemia. Induction of myocardial ischemia by ligation of the left anterior descending (LAD) coronary artery caused a systemic rise in PAPP-A. However, the ischemic myocardium was excluded as the source of PAPP-A. Interestingly, induction of ischemia in peripheral tissues by ligation of the left femoral artery caused a systemic rise in PAPP-A originating from the left hind limb. This is the first study to demonstrate PAPP-A elevations in the absence of atherosclerosis or heparin during myocardial ischemia. Our findings thus add to the current discussion of the usefulness of PAPP-A as a biomarker for ACS.

Two middle-age-onset hemochromatosis patients with heterozygous mutations in the hemojuvelin gene in a Chinese family.

PubMed

Li, Shufeng; Xue, Jun; Chen, Baojun; Wang, Qiwei; Shi, Minke; Xie, Xiaojing; Zhang, Liang

2014-04-01

Hereditary hemochromatosis is a disorder characterized by enhanced intestinal absorption of dietary iron. Here, we report a heterozygous genotype at two mutation sites in hemojuvelin (HJV) present in two brothers with middle-age-onset hemochromatosis in a Chinese family. To date, only homozygous or compound heterozygous states of HJV gene have been reported as associated with iron overload. However, the patients here were heterozygous for two mutations in one HJV allele in cis: a premature termination mutation (962G>A and 963C>A; C321X) and a mutation in the signal peptide (18G>C; Q6H). Previously unrecognized environmental or other genetic factors may have interacted with the heterozygous genotype in these patients.

Spatial variation of crustal coda Q in California

USGS Publications Warehouse

Philips, W.S.; Lee, W.H.K.; Newberry, J.T.

1988-01-01

Coda wave data from California microearthquakes were studied in order to delineate regional fluctuations of apparent crustal attenuation in the band 1.5 to 24 Hz. Apparent attenuation was estimated using a single back scattering model of coda waves. The coda wave data were restricted to ???30 s following the origin time; this insures that crustal effects dominate the results as the backscattered shear waves thought to form the coda would not have had time to penetrate much deeper. Results indicate a strong variation in apparent crustal attenuation at high frequencies between the Franciscan and Salinian regions of central California and the Long Valley area of the Sierra Nevada. Although the coda Q measurements coincide at 1.5 Hz (Qc=100), at 24 Hz there is a factor of four difference between the measurements made in Franciscan (Qc=525) and Long Valley (Qc=2100) with the Salinian midway between (Qc=900). These are extremely large variations compared to measures of seismic velocities of comparable resolution, demonstrating the exceptional sensitivity of the high frequency coda Q measurement to regional geology. In addition, the frequency trend of the results is opposite to that seen in a compilation of coda Q measurements made worldwide by other authors which tend to converge at high and diverge at low frequencies, however, the worldwide results generally were obtained without limiting the coda lengths and probably reflect upper mantle rather than crustal properties. Our results match those expected due to scattering in random media represented by Von Karman autocorrelation functions of orders 1/2 to 1/3. The Von Karman medium of order 1/3 corresponding to the Franciscan coda Q measurement contains greater amounts of high wavenumber fluctuations. This indicates relatively large medium fluctuations with wavelengths on the order of 100 m in the highly deformed crust associated with the Franciscan, however, the influence of scattering on the coda Q measurement is currently a matter of controversy. ?? 1988 Birkha??user Verlag.

Study of the in-medium nucleon electromagnetic form factors using a light-front nucleon wave function combined with the quark-meson coupling model

NASA Astrophysics Data System (ADS)

de Araújo, W. R. B.; de Melo, J. P. B. C.; Tsushima, K.

2018-02-01

We study the nucleon electromagnetic (EM) form factors in symmetric nuclear matter as well as in vacuum within a light-front approach using the in-medium inputs calculated by the quark-meson coupling model. The same in-medium quark properties are used as those used for the study of in-medium pion properties. The zero of the proton EM form factor ratio in vacuum, the electric to magnetic form factor ratio μpGEp (Q2) /GMp (Q2) (Q2 = -q2 > 0 with q being the four-momentum transfer), is determined including the latest experimental data by implementing a hard constituent quark component in the nucleon wave function. A reasonable fit is achieved for the ratio μpGEp (Q2) /GMp (Q2) in vacuum, and we predict that the Q02 value to cross the zero of the ratio to be about 15 GeV2. In addition the double ratio data of the proton EM form factors in 4He and H nuclei, [GEp4He (Q2) /G4HeMp (Q2) ] / [GEp1H (Q2) /GMp1H (Q2) ], extracted by the polarized (e → ,e‧ p →) scattering experiment on 4He at JLab, are well described. We also predict that the Q02 value satisfying μpGEp (Q02) /GMp (Q0 2) = 0 in symmetric nuclear matter, shifts to a smaller value as increasing nuclear matter density, which reflects the facts that the faster falloff of GEp (Q2) as increasing Q2 and the increase of the proton mean-square charge radius. Furthermore, we calculate the neutron EM form factor double ratio in symmetric nuclear matter for 0.1

Multi-stage phononic crystal structure for anchor-loss reduction of thin-film piezoelectric-on-silicon microelectromechanical-system resonator

NASA Astrophysics Data System (ADS)

Bao, Fei-Hong; Bao, Lei-Lei; Li, Xin-Yi; Ammar Khan, Muhammad; Wu, Hua-Ye; Qin, Feng; Zhang, Ting; Zhang, Yi; Bao, Jing-Fu; Zhang, Xiao-Sheng

2018-06-01

Thin-film piezoelectric-on-silicon acoustic wave resonators are promising for the development of system-on-chip integrated circuits with micro/nano-engineered timing reference. However, in order to realize their large potentials, a further enhancement of the quality factor (Q) is required. In this study, a novel approach, based on a multi-stage phononic crystal (PnC) structure, was proposed to achieve an ultra-high Q. A systematical study revealed that the multi-stage PnC structure formed a frequency-selective band-gap to effectively prohibit the dissipation of acoustic waves through tethers, which significantly reduced the anchor loss, leading to an insertion-loss reduction and enhancement of Q. The maximum unloaded Q u of the fabricated resonators reached the value of ∼10,000 at 109.85 MHz, indicating an enhancement by 19.4 times.

Q^2 Dependence of the S_{11}(1535) Photocoupling and Evidence for a P-wave resonance in eta electroproduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haluk Denizli; James Mueller; Steven Dytman

2007-07-01

New cross sections for the reactionmore » $$ep \\to e'\\eta p$$ are reported for total center of mass energy $W$=1.5--2.3 GeV and invariant squared momentum transfer $Q^2$=0.13--3.3 GeV$^2$. This large kinematic range allows extraction of new information about response functions, photocouplings, and $$\\eta N$$ coupling strengths of baryon resonances. A sharp structure is seen at $$W\\sim$$ 1.7 GeV. The shape of the differential cross section is indicative of the presence of a $P$-wave resonance that persists to high $Q^2$. Improved values are derived for the photon coupling amplitude for the $$S_{11}$$(1535) resonance. The new data greatly expands the $Q^2$ range covered and an interpretation of all data with a consistent parameterization is provided.« less

Wave propagation, scattering and emission in complex media

NASA Astrophysics Data System (ADS)

Jin, Ya-Qiu

I. Polarimetric scattering and SAR imagery. EM wave propagation and scattering in polarimetric SAR interferometry / S. R. Cloude. Terrain topographic inversion from single-pass polarimetric SAR image data by using polarimetric stokes parameters and morphological algorithm / Y. Q. Jin, L. Luo. Road detection in forested area using polarimetric SAR / G. W. Dong ... [et al.]. Research on some problems about SAR radiometric resolution / G. Dong ... [et al.]. A fast image matching algorithm for remote sensing applications / Z. Q. Hou ... [et al.]. A new algorithm of noised remote sensing image fusion based on steerable filters / X. Kang ... [et al.]. Adaptive noise reduction of InSAR data based on anisotropic diffusion models and their applications to phase unwrapping / C. Wang, X. Gao, H. Zhang -- II. Scattering from randomly rough surfaces. Modeling tools for backscattering from rough surfaces / A. K. Fung, K. S. Chen. Pseudo-nondiffracting beams from rough surface scattering / E. R. Méndez, T. A. Leskova, A. A. Maradudin. Surface roughness clutter effects in GPR modeling and detection / C. Rappaport. Scattering from rough surfaces with small slopes / M. Saillard, G. Soriano. Polarization and spectral characteristics of radar signals reflected by sea-surface / V. A. Butko, V. A. Khlusov, L. I. Sharygina. Simulation of microwave scattering from wind-driven ocean surfaces / M. Y. Xia ... [et al.]. HF surface wave radar tests at the Eastern China Sea / X. B. Wu ... [et al.] -- III. Electromagnetics of complex materials. Wave propagation in plane-parallel metamaterial and constitutive relations / A. Ishimaru ... [et al.]. Two dimensional periodic approach for the study of left-handed metamaterials / T. M. Grzegorczyk ... [et al.]. Numerical analysis of the effective constitutive parameters of a random medium containing small chiral spheres / Y. Nanbu, T. Matsuoka, M. Tateiba. Wave propagation in inhomogeneous media: from the Helmholtz to the Ginzburg -Landau equation / M. Gitterman. Transformation of the spectrum of scattered radiation in randomly inhomogeneous absorptive plasma layer / G. V. Jandieri, G. D. Aburjunia, V. G. Jandieri. Numerical analysis of microwave heating on saponification reaction / K. Huang, K. Jia -- IV. Scattering from complex targets. Analysis of electromagnetic scattering from layered crossed-gratings of circular cylinders using lattice sums technique / K. Yasumoto, H. T. Jia. Scattering by a body in a random medium / M. Tateiba, Z. Q. Meng, H. El-Ocla. A rigorous analysis of electromagnetic scattering from multilayered crossed-arrays of metallic cylinders / H. T. Jia, K. Yasumoto. Vector models of non-stable and spatially-distributed radar objects / A. Surkov ... [et al.]. Simulation of algorithm of orthogonal signals forming and processing used to estimate back scattering matrix of non-stable radar objects / D. Nosov ... [et al.]. New features of scattering from a dielectric film on a reflecting metal substrate / Z. H. Gu, I. M. Fuks, M. Ciftan. A higher order FDTD method for EM wave propagation in collision plasmas / S. B. Liu, J. J. Mo, N. C. Yuan -- V. Radiative transfer and remote sensing. Simulating microwave emission from Antarctica ice sheet with a coherent model / M. Tedesco, P. Pampaloni. Scattering and emission from inhomogeneous vegetation canopy and alien target by using three-dimensional Vector Radiative Transfer (3D-VRT) equation / Y. Q. Jin, Z. C. Liang. Analysis of land types using high-resolution satellite images and fractal approach / H. G. Zhang ... [et al.]. Data fusion of RADARSAT SAR and DMSP SSM/I for monitoring sea ice of China's Bohai Sea / Y. Q. Jin. Retrieving atmospheric temperature profiles from simulated microwave radiometer data with artificial neural networks / Z. G. Yao, H. B. Chen -- VI. Wave propagation and wireless communication. Wireless propagation in urban environments: modeling and experimental verification / D. Erricolo ... [et al.]. An overview of physics-based wave propagation in forested environment / K. Sarabandi, I. Koh. Angle-of-arrival fluctuations due to meteorological conditions in the diffraction zone of C-band radio waves, propagated over the ground surface / T. A. Tyufilina, A. A. Meschelyakov, M. V. Krutikov. Simulating radio channel statistics using ray based prediction codes / H. L. Bertoni. Measurement and simulation of ultra wideband antenna elements / W. Sörgel, W. Wiesbeck. The experimental investigation of a ground-placed radio complex synchronization system / V. P. Denisov ... [et al.] -- VII. Computational electromagnetics. Analysis of 3-D electromagnetic wave scattering with the Krylov subspace FFT iterative methods / R. S. Chen ... [et al.]. Sparse approximate inverse preconditioned iterative algorithm with block toeplitz matrix for fast analysis of microstrip circuits / L. Mo, R. S. Chen, E. K. N. Yung. An Efficient modified interpolation technique for the translation operators in MLFMA / J. Hu, Z. P. Nie, G. X. Zou. Efficient solution of 3-D vector electromagnetic scattering by CG-MLFMA with partly approximate iteration / J. Hu, Z. P. Nie. The effective constitution at interface of different media / L. G. Zheng, W. X. Zhang. Novel basis functions for quadratic hexahedral edge element / P. Liu ... [et al.]. A higher order FDTD method for EM wave propagation in collision plasmas / S. B. Liu, J. J. Mo, N. C. Yuan. Attenuation of electric field eradiated by underground source / J. P. Dong, Y. G. Gao.

Influence of presenting electrocardiographic findings on the treatment and outcomes of patients with non-ST-segment elevation myocardial infarction.

PubMed

Patel, Jigar H; Gupta, Raghav; Roe, Matthew T; Peng, S Andrew; Wiviott, Stephen D; Saucedo, Jorge F

2014-01-15

The influence of the presenting electrocardiographic (ECG) findings on the treatment and outcomes of patients with non-ST-segment elevation myocardial infarction (NSTEMI) has not been studied in contemporary practice. We analyzed the clinical characteristics, in-hospital management, and in-hospital outcomes of patients with NSTEMI in the Acute Coronary Treatment and Intervention Outcomes Network Registry-Get With The Guidelines (ACTION Registry-GWTG) according to the presenting ECG findings. A total of 175,556 patients from 485 sites from January 2007 to September 2011 were stratified by the ECG findings on presentation: ST depression (n = 40,146, 22.9%), T-wave inversions (n = 24,627, 14%), transient ST-segment elevation (n = 5,050, 2.9%), and no ischemic changes (n = 105,733, 60.2%). Patients presenting with ST-segment depression were the oldest and had the greatest prevalence of major cardiac risk factors. Coronary angiography was performed most frequently in the transient ST-segment elevation group, followed by the T-wave inversion, ST-segment depression, and no ischemic changes groups. The angiogram revealed that patients with ST-segment depression had more left main, proximal left anterior descending, and 3-vessel coronary artery disease and underwent coronary artery bypass grafting most often. In contrast, patients with transient ST-segment elevation had 1-vessel CAD and underwent percutaneous coronary intervention the most. The unadjusted mortality was highest in the ST-segment depression group, followed by the no ischemic changes, transient ST-segment elevation, and T-wave inversion group. Adjusted mortality using the ACTION Registry-GWTG in-hospital mortality model with the no ischemic changes group as the reference showed that in-hospital mortality was similar in the transient ST-segment elevation (odds ratio 1.15, 95% confidence interval 0.97 to 1.37; p = 0.10), higher in the ST-segment depression group (odds ratio 1.46, 95% confidence interval 1.37 to 1.54; p <0.0001), and lower in the T-wave inversion group (odds ratio 0.91, 95% confidence interval 0.83 to 0.99; p = 0.026). In conclusion, the clinical and angiographic characteristics and treatment and outcomes of patients with NSTEMI differed substantially according to the presenting ECG findings. Patients with ST-segment depression have a greater burden of co-morbidities and coronary atherosclerosis and have a greater risk of adjusted in-hospital mortality compared with the other groups. These findings highlight the importance of integrating the presenting ECG findings into the risk stratification algorithm for patients with NSTEMI. Copyright © 2014 Elsevier Inc. All rights reserved.

The Brazilian Family Health Program and Secondary Stroke and Myocardial Infarction Prevention: A 6-Year Cohort Study

PubMed Central

Franco, Selma; Longo, Alexandre; Moro, Carla; Buss, Talita A.; Collares, Daniel; Werlich, Roberta; Dadan, Danieli D.; Fissmer, Cristiane S.; Aragão, Ana; Ferst, Priscilla; Palharini, Felipe G.; Eluf-Neto, Jose; Fonseca, Luiz A. M.; Whiteley, William N.; Gonçalves, Anderson R. R.

2012-01-01

Objectives. We compared the incidence of recurrent or fatal cardiovascular disease in patients using Brazil’s government-run Family Health Program (FHP) with those using non-FHP models of care. Methods. From 2005 to 2010, we followed outpatients discharged from city public hospitals after a first ever stroke for stroke recurrence and myocardial infarction, using data from all city hospitals, death certificates, and outpatient monitoring in state-run and private units. Results. In the follow-up period, 103 patients in the FHP units and 138 in the non-FHP units had exclusively state-run care. Stroke or myocardial infarction occurred in 30.1% of patients in the FHP group and 36.2% of patients in non-FHP care (rate ratio [RR] = 0.85; 95% confidence interval [CI] = 0.61, 1.18; P = .39); 37.9% of patients in FHP care and 54.3% in non-FHP care (RR = 0.68; 95% CI = 0.50, 0.92; P = .01) died. FHP use was associated with lower hazard of death from all causes (hazard ratio [HR] = 0.58; P = .005) after adjusting for age and stroke severity. The absolute risk reduction for death by all causes was 16.4%. Conclusions. FHP care is more effective than is non-FHP care at preventing death from secondary stroke and myocardial infarction. PMID:23078478

Depression and Heart Diseases: Leading Health Problems.

PubMed

Raič, Matea

2017-12-01

Depression is the most common psychiatric disorder in the world population and the most frequent mental disorder in a primary health care. Unrecognized and untreated depression is associated with a poor outcome of treated chronic diseases which co-exist with depression. Depression and cardiovascular diseases are bidirectional related conditions, risks are for each other, and they often co-exist. Depression is a common disorder in cardiovascular patients with a prevalence of 20% to 45%, which is much more frequent than in the general population. In cardiac patients with acute myocardial infarction, depression occurs three times more often than in the general population. Depression has a direct effect on the pathophysiological changes of various organ systems, changing the values of blood pressure, heart rate, vasomotor tone, vascular resistance, blood viscosity and plasma volume. The potential mechanism for developing heart disease in depressed patients includes hypothalamic-pituitary-adrenal gland dysfunction, increased proinflammatory and prothrombotic factor activity, reduced omega-3 fatty acids, reduced heart rate variability, smoking, physical inactivity, reduced mood, self-esteem and self-efficacy.

Fully Nonlinear Edge Gyrokinetic Simulations of Kinetic Geodesic-Acoustic Modes and Boundary Flows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, X Q; Belli, E; Bodi, K

We present edge gyrokinetic neoclassical simulations of tokamak plasmas using the fully nonlinear (full-f) continuum code TEMPEST. A nonlinear Boltzmann model is used for the electrons. The electric field is obtained by solving the 2D gyrokinetic Poisson Equation. We demonstrate the following: (1) High harmonic resonances (n > 2) significantly enhance geodesic-acoustic mode (GAM) damping at high-q (tokamak safety factor), and are necessary to explain both the damping observed in our TEMPEST q-scans and experimental measurements of the scaling of the GAM amplitude with edge q{sub 95} in the absence of obvious evidence that there is a strong q dependencemore » of the turbulent drive and damping of the GAM. (2) The kinetic GAM exists in the edge for steep density and temperature gradients in the form of outgoing waves, its radial scale is set by the ion temperature profile, and ion temperature inhomogeneity is necessary for GAM radial propagation. (3) The development of the neoclassical electric field evolves through different phases of relaxation, including GAMs, their radial propagation, and their long-time collisional decay. (4) Natural consequences of orbits in the pedestal and scrape-off layer region in divertor geometry are substantial non-Maxwellian ion distributions and flow characteristics qualitatively like those observed in experiments.« less

The Shannon entropy information for mixed Manning Rosen potential in D-dimensional Schrodinger equation

NASA Astrophysics Data System (ADS)

Suparmi, A.; Cari, C.; Nur Pratiwi, Beta; Arya Nugraha, Dewanta

2017-01-01

D dimensional Schrodinger equation for the mixed Manning Rosen potential was investigated using supersymmetric quantum mechanics. We obtained the energy eigenvalues from radial part solution and wavefunctions in radial and angular parts solution. From the lowest radial wavefunctions, we evaluated the Shannon entropy information using Matlab software. Based on the entropy densities demonstrated graphically, we obtained that the wave of position information entropy density moves right when the value of potential parameter q increases, while its wave moves left with the increase of parameter α. The wave of momentum information entropy densities were expressed in graphs. We observe that its amplitude increase with increasing parameter q and α

Fault-zone guided waves from explosions in the San Andreas fault at Parkfield and Cienega Valley, California

USGS Publications Warehouse

Li, Y.-G.; Ellsworth, W.L.; Thurber, C.H.; Malin, P.E.; Aki, K.

1997-01-01

Fault-zone guided waves were successfully excited by near-surface explosions in the San Andreas fault zone both at Parkfield and Cienega Valley, central California. The guided waves were observed on linear, three-component seismic arrays deployed across the fault trace. These waves were not excited by explosions located outside the fault zone. The amplitude spectra of guided waves show a maximum peak at 2 Hz at Parkfield and 3 Hz at Cienega Valley. The guided wave amplitude decays sharply with observation distance from the fault trace. The explosion-excited fault-zone guided waves are similar to those generated by earthquakes at Parkfield but have lower frequencies and travel more slowly. These observations suggest that the fault-zone wave guide has lower seismic velocities as it approaches the surface at Parkfield. We have modeled the waveforms as S waves trapped in a low-velocity wave guide sandwiched between high-velocity wall rocks, resulting in Love-type fault-zone guided waves. While the results are nonunique, the Parkfield data are adequately fit by a shallow wave guide 170 m wide with an S velocity 0.85 km/sec and an apparent Q ??? 30 to 40. At Cienega Valley, the fault-zone wave guide appears to be about 120 m wide with an S velocity 0.7 km/sec and a Q ??? 30.

Effects of mTOR/NF-κB signaling pathway and high thoracic epidural anesthesia on myocardial ischemia-reperfusion injury via autophagy in rats.

PubMed

Huang, Wei-Qiang; Wen, Jian-Lin; Lin, Ri-Qi; Wei, Peng; Huang, Feng

2018-09-01

We investigated the role of mammalian target of rapamycin/nuclear factor-kappa B (mTOR/NF-κB) signaling pathway in high thoracic epidural anesthesia (HTEA) against myocardial ischemia-reperfusion (I/R) injury in rats. The rat model of myocardial I/R injury was established. Ninety rats were divided into the normal, sham, I/R, eHTEA, the PDTC, and HTEA + PDTC groups. ELISA was applied to detect cardiac function indexes. HE staining was conducted to observe histopathological changes of myocardial tissues, and TTC staining was performed to detect the myocardial infarction size. TUNEL staining was adopted to detect the cell apoptosis rate. The mRNA and protein levels of mTOR, NF-κB, Fasl, Bcl-2 and Bax, and LC3-I, LC3-II, BNIP3, and Atg5 were detected by RT-qPCR and Western blotting, respectively. The findings indicated that compared with the normal and sham groups, the I/R, PDTC, and HTEA groups showed the larger myocardial infarction size and increased cell apoptosis rate, while the results in the HTEA + PDTC group were opposite. Compared with the normal and sham groups, the I/R group showed reduced mRNA and protein levels of Bcl-2, LC3, BNIP3, and Atg5, and elevated mRNA and protein levels of mTOR, p50, p65, Bax, and Fasl, while the HTEA + PDTC group revealed the opposite results, and the PDTC and HTEA group revealed the increased mRNA and protein levels of Bcl-2, LC3, BNIP3, Atg5, mTOR, p50, p65, Bax, and Fasl. These results prove that the inhibition of mTOR/NF-κB signaling pathway potentiates HTEA against myocardial IR injury by autophagy and apoptosis in rats. © 2017 Wiley Periodicals, Inc.

SITUATION OF THE SPANISH AMERICANS OF NORTHERN NEW MEXICO.

ERIC Educational Resources Information Center

KNOWLTON, CLARK S.

THE SPANISH AMERICANS OF NORTHERN NEW MEXICO HAVE CONSTITUTED ONE OF THE UNRECOGNIZED DISADVANTAGED GROUPS. PER CAPITA INCOME IS LOW AND THE RATES OF UNEMPLOYMENT AND WELFARE ARE HIGH. THE CAUSES OF THE PRESENT SITUATION ARE--(1) LOSS OF LAND, (2) CULTURAL AND LINGUISTIC DISCRIMINATORY ATTITUDES, (3) NON-PROVISION OF ADEQUATE PROGRAMS TO…

HLA-DR-, CD33+, CD56+, CD16- myeloid/natural killer cell acute leukemia: a previously unrecognized form of acute leukemia potentially misdiagnosed as French-American-British acute myeloid leukemia-M3.

PubMed

Scott, A A; Head, D R; Kopecky, K J; Appelbaum, F R; Theil, K S; Grever, M R; Chen, I M; Whittaker, M H; Griffith, B B; Licht, J D

1994-07-01

We have identified and characterized a previously unrecognized form of acute leukemia that shares features of both myeloid and natural killer (NK) cells. From a consecutive series of 350 cases of adult de novo acute myeloid leukemia (AML), we identified 20 cases (6%) with a unique immunophenotype: CD33+, CD56+, CD11a+, CD13lo, CD15lo, CD34+/-, HLA-DR-, CD16-. Multicolor flow cytometric assays confirmed the coexpression of myeloid (CD33, CD13, CD15) and NK cell-associated (CD56) antigens in each case, whereas reverse transcription polymerase chain reaction (RT-PCR) assays confirmed the identity of CD56 (neural cell adhesion molecule) in leukemic blasts. Although two cases expressed CD4, no case expressed CD2, CD3, or CD8 and no case showed clonal rearrangement of genes encoding the T-cell receptor (TCR beta, gamma, delta). Leukemic blasts in the majority of cases shared unique morphologic features (deeply invaginated nuclear membranes, scant cytoplasm with fine azurophilic granularity, and finely granular Sudan black B and myeloperoxidase cytochemical reactivity) that were remarkably similar to those of acute promyelocytic leukemia (APL); particularly the microgranular variant (FAB AML-M3v). However, all 20 cases lacked the t(15;17) and 17 cases tested lacked the promyelocytic/retinoic acid receptor alpha (RAR alpha) fusion transcript in RT-PCR assays; 12 cases had 46,XX or 46,XY karyotypes, whereas 2 cases had abnormalities of chromosome 17q: 1 with del(17)(q25) and the other with t(11;17)(q23;q21) and the promyelocytic leukemia zinc finger/RAR alpha fusion transcript. All cases tested (6/20), including the case with t(11;17), failed to differentiate in vitro in response to all-trans retinoic acid (ATRA), suggesting that these cases may account for some APLs that have not shown a clinical response to ATRA. Four of 6 cases tested showed functional NK cell-mediated cytotoxicity, suggesting a relationship between these unique CD33+, CD56+, CD16- acute leukemias and normal CD56+, CD16- NK precursor cells. Using a combination of panning and multiparameter flow cytometric sorting, we identified a normal CD56+, CD33+, CD16- counterpart cell at a frequency of 1% to 2% in the peripheral blood of healthy individuals. Our studies suggest that this form of acute leukemia may arise from transformation of a precursor cell common to both the myeloid and NK cell lineages; thus we propose the designation myeloid/NK acute leukemia. Recognition of this new leukemic entity will be important in distinguishing these ATRA-nonresponsive cases from ATRA-responsive true APL.

The influence of shear-velocity heterogeneity on ScS2/ScS amplitude ratios and estimates of Q in the mantle

NASA Astrophysics Data System (ADS)

Chaves, Carlos A. M.; Ritsema, Jeroen

2016-08-01

Regional waveforms of deep-focus Tonga-Fiji earthquakes indicate anomalous traveltime differences (ScS2-ScS) and amplitude ratios (ScS2/ScS) of the phases ScS and ScS2. The correlation between the ScS2-ScS delay time and the ScS2/ScS amplitude ratio suggests that shear wave apparent Q in the mantle below the Tonga-Fiji region is highest when shear wave velocities are lowest. This observation is unexpected if temperature variations were responsible for the seismic anomalies. Using spectral element method waveform simulations for four tomographic models, we demonstrate that focusing and scattering of shear waves by long-wavelength 3-D heterogeneity in the mantle may overwhelm the signal from intrinsic attenuation in long-period ScS2/ScS amplitude ratios. The tomographic models reproduce the trends in recorded ScS2-ScS difference times and ScS2/ScS amplitude ratios. Although they cannot be ruled out, variations in shear wave attenuation (i.e., the quality factor Q) are not necessary to explain the data.

Processing of a nine-component near-offset VSP for seismic anisotropy

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacBeth, C.; Li, X.Y.; Zeng, X.

1997-03-01

A convolutional sequence of matrix operators is offered as a convenient deterministic scheme for processing a multicomponent vertical seismic profile (VSP). This sequence is applied to a nine-component near-offset VSP recorded at the Conoco borehole test facility, Kay County, Oklahoma. These data are corrected for tool spin and near-surface anisotropy together with source coupling or imbalance. After wave-field separation using a standard f-k filter, each source and receiver pair for the upgoing waves is adjusted to a common reference depth using a matrix operator based on the downgoing wavefield. The up- and downgoing waves are then processed for anisotropy bymore » a similarity transformation, to separate the qS1 and qS2 waves, from which the anisotropic properties are estimated. These estimates reveal a strong (apparent) vertical birefringence in the near-surface, but weak or moderate values for the majority of the subsurface. The target zone consists of a thin sandstone and deeper shale layer, both of which possess a strong vertical birefringence. The sandstone corresponds to a zone of known fluid flow. An observed qS2 attenuation and polarization change in the shale suggest it contains large fractures.« less

The detectability of high frequency energy at teleseismic and regional distances, 1. Studies of radiation from high-explosive and nuclear cratering events, 2

NASA Astrophysics Data System (ADS)

der, Z. A.; Blandford, R. R.

1981-03-01

A survey of the literature on short period seismic studies showed that seismic waves of high frequency in the 3-10 Hz range can be observed regularly at both regional and teleseismic distances. These observations show that the low Q values proposed for the long period seismic waves cannot be valid in the short period band. The data indicate that, in the mantle, Q increases with frequency and may be as much as five times higher at 5-10 Hz than in the long period band. Even with the most conservative assumptions, the level of high frequency amplitudes in the teleseismic P waves exceeds that predicted with a constant t*p = 1 sec by a factor of at least 100,000 at and beyond 5 Hz. The apparent Q beta of the lithosphere, which may be largely due to scattering by the small scale inhomogeneities in the crust, also shows an increase with frequency by as much as a factor of four within the 1-10 Hz band. This parameter controls the attenuation and the detectability of seismic waves at regional distances such as Pn, Pg, Su and Lg.

Internal transport barrier triggered by non-linear lower hybrid wave deposition under condition of beam-driven toroidal rotation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Q. D., E-mail: qgao@swip.ac.cn; Budny, R. V.

2015-03-15

By using gyro-Landau fluid transport model (GLF23), time-dependent integrated modeling is carried out using TRANSP to explore the dynamic process of internal transport barrier (ITB) formation in the neutral beam heating discharges. When the current profile is controlled by LHCD (lower hybrid current drive), with appropriate neutral beam injection, the nonlinear interplay between the transport determined gradients in the plasma temperature (T{sub i,e}) and toroidal velocity (V{sub ϕ}) and the E×B flow shear (including q-profile) produces transport bifurcations, generating spontaneously a stepwise growing ITB. In the discharge, the constraints imposed by the wave propagation condition causes interplay of the LHmore » driven current distribution with the plasma configuration modification, which constitutes non-linearity in the LH wave deposition. The non-linear effects cause bifurcation in LHCD, generating two distinct quasi-stationary reversed magnetic shear configurations. The change of current profile during the transition period between the two quasi-stationary states results in increase of the E×B shearing flow arising from toroidal rotation. The turbulence transport suppression by sheared E×B flow during the ITB development is analysed, and the temporal evolution of some parameters characterized the plasma confinement is examined. Ample evidence shows that onset of the ITB development is correlated with the enhancement of E×B shearing rate caused by the bifurcation in LHCD. It is suggested that the ITB triggering is associated with the non-linear effects of the LH power deposition.« less

Physics of Earthquake Disaster: From Crustal Rupture to Building Collapse

NASA Astrophysics Data System (ADS)

Uenishi, Koji

2018-05-01

Earthquakes of relatively greater magnitude may cause serious, sometimes unexpected failures of natural and human-made structures, either on the surface, underground, or even at sea. In this review, by treating several examples of extraordinary earthquake-related failures that range from the collapse of every second building in a commune to the initiation of spontaneous crustal rupture at depth, we consider the physical background behind the apparently abnormal earthquake disaster. Simple but rigorous dynamic analyses reveal that such seemingly unusual failures actually occurred for obvious reasons, which may remain unrecognized in part because in conventional seismic analyses only kinematic aspects of the effects of lower-frequency seismic waves below 1 Hz are normally considered. Instead of kinematics, some dynamic approach that takes into account the influence of higher-frequency components of waves over 1 Hz will be needed to anticipate and explain such extraordinary phenomena and mitigate the impact of earthquake disaster in the future.

Localised Nonlinear Waves in the Three-Component Coupled Hirota Equations

NASA Astrophysics Data System (ADS)

Xu, Tao; Chen, Yong

2017-10-01

We construct the Lax pair and Darboux transformation for the three-component coupled Hirota equations including higher-order effects such as third-order dispersion, self-steepening, and stimulated Raman scattering. A special vector solution of the Lax pair with 4×4 matrices for the three-component Hirota system is elaborately generated, based on this vector solution, various types of mixed higher-order localised waves are derived through the generalised Darboux transformation. Instead of considering various arrangements of the three potential functions q1, q2, and q3, here, the same combination is considered as the same type solution. The first- and second-order localised waves are mainly discussed in six mixed types: (1) the hybrid solutions degenerate to the rational ones and three components are all rogue waves; (2) two components are hybrid solutions between rogue wave (RW) and breather (RW+breather), and one component is interactional solution between RW and dark soliton (RW+dark soliton); (3) two components are RW+dark soliton, and one component is RW+bright soliton; (4) two components are RW+breather, and one component is RW+bright soliton; (5) two components are RW+dark soliton, and one component is RW+bright soliton; (6) three components are all RW+breather. Moreover, these nonlinear localised waves merge with each other by increasing the absolute values of two free parameters α, β. These results further uncover some striking dynamic structures in the multicomponent coupled system.

Agradient velocity, vortical motion and gravity waves in a rotating shallow-water model

NASA Astrophysics Data System (ADS)

Sutyrin Georgi, G.

2004-07-01

A new approach to modelling slow vortical motion and fast inertia-gravity waves is suggested within the rotating shallow-water primitive equations with arbitrary topography. The velocity is exactly expressed as a sum of the gradient wind, described by the Bernoulli function,B, and the remaining agradient part, proportional to the velocity tendency. Then the equation for inverse potential vorticity,Q, as well as momentum equations for agradient velocity include the same source of intrinsic flow evolution expressed as a single term J (B, Q), where J is the Jacobian operator (for any steady state J (B, Q) = 0). Two components of agradient velocity are responsible for the fast inertia-gravity wave propagation similar to the traditionally used divergence and ageostrophic vorticity. This approach allows for the construction of balance relations for vortical dynamics and potential vorticity inversion schemes even for moderate Rossby and Froude numbers assuming the characteristic value of |J(B, Q)| = to be small. The components of agradient velocity are used as the fast variables slaved to potential vorticity that allows for diagnostic estimates of the velocity tendency, the direct potential vorticity inversion with the accuracy of 2 and the corresponding potential vorticity-conserving agradient velocity balance model (AVBM). The ultimate limitations of constructing the balance are revealed in the form of the ellipticity condition for balanced tendency of the Bernoulli function which incorporates both known criteria of the formal stability: the gradient wind modified by the characteristic vortical Rossby wave phase speed should be subcritical. The accuracy of the AVBM is illustrated by considering the linear normal modes and coastal Kelvin waves in the f-plane channel with topography.

CSDP: The seismology of continental thermal regimes

NASA Astrophysics Data System (ADS)

Aki, K.

1991-05-01

The past year continued to be extremely productive following up two major breakthroughs made in the preceding year. One of the breakthroughs was the derivation of an integral equation for time-dependent power spectra, which unified all the existing theories on seismic scattering including the radiative transfer theory for total energy and single-multiple scattering theories based on the ray approach. We successfully applied the method to the data from the United States Geological Survey (USGS) regional seismic arrays in central California, Long Valley and Island of Hawaii, and obtained convincing results on the scattering Q(sup -1) and intrinsic Q(sup -1) in these areas for the frequency range from 1 Hz to 20 Hz. The frequency dependence of scattering Q(sup -1) is, then, interpreted in terms of random medium with continuous or discrete scatterers. The other breakthrough was the application of T-matrix formulation to the seismic scattering problem. We are currently working on two dimensional inclusions with high and low velocity contrast with the surrounding medium. In addition to the above two main lines of research, we were able to use so-called 'T-phase' observed on the Island of Hawaii to map the Q value with a good spatial resolution. The T-phase is seismic waves converted from acoustic waves propagated through the sofar channel of the ocean. We found that we can eliminate remarkably well the frequency dependent recording site effect from the T-phase amplitude using the amplification factor for coda waves, further confirming the fundamental separability of source, path and site effects for coda waves, and proving the effectiveness of stochastic modeling of high-frequency seismic waves.

Microwave bulk-acoustic-wave reflection-grating resonators.

PubMed

Oates, D E; Pan, J Y

1988-01-01

A technique for fabrication of bulk-acoustic-wave (BAW) resonators operating at fundamental frequencies between 1 and 10 GHz is presented. The resonators utilize a reflection grating made by optical holographic methods in iron-doped lithium niobate. Q factors of 30000 at 1 GHz have been demonstrated. Extension to Q of 10000 at 10 GHz appears feasible. Projected limitations to performance are discussed. The high Q at the high fundamental frequency directly results in low-phase noise. Phase-noise measurements of BAW resonator-stabilized oscillators operating at 1.14 GHz are presented. The single-sideband noise floor of <-140 dBc/Hz is shown to be in agreement with an analytical model. Projected improvements in the devices and circuits promise performance of <-160 dBc/Hz.

A continuous-wave and passively Q-switched Nd:LaGGG laser at 937 nm

NASA Astrophysics Data System (ADS)

Li, Z.-Y.; Ying, H.-Y.; Yang, H.; He, J.-L.

2013-10-01

A diode-end-pumped continuous-wave (CW) and passively Q-switched Nd:LaGGG (GGG: gadolinium gallium garnet) laser at about 937 nm was demonstrated for the first time. The maximum CW output power of 540 mW was obtained with the optical-optical conversion efficiency of 3.2% and the slope efficiency of 4.4%. A V3+:YAG (yttrium aluminum garnet) saturable absorber with the initial transmission of 97% was used for the passive Q-switching regime. The shortest pulse width was achieved as 500 ns with the pulse repetition rate of 96 kHz. The corresponding single-pulse energy and pulse peak power were determined as 1.56 μJ and 3.12 W, respectively.

On a q-extension of the linear harmonic oscillator with the continuous orthogonality property on ℝ

NASA Astrophysics Data System (ADS)

Alvarez-Nodarse, R.; Atakishiyeva, M. K.; Atakishiyev, N. M.

2005-11-01

We discuss a q-analogue of the linear harmonic oscillator in quantum mechanics based on a q-extension of the classical Hermite polynomials H n ( x) recently introduced by us in R. Alvarez-Nodarse et al.: Boletin de la Sociedad Matematica Mexicana (3) 8 (2002) 127. The wave functions in this q-model of the quantum harmonic oscillator possess the continuous orthogonality property on the whole real line ℝ with respect to a positive weight function. A detailed description of the corresponding q-system is carried out.

Taxonomy of segmental myocardial systolic dysfunction

PubMed Central

McDiarmid, Adam K.; Pellicori, Pierpaolo; Cleland, John G.; Plein, Sven

2017-01-01

The terms used to describe different states of myocardial health and disease are poorly defined. Imprecision and inconsistency in nomenclature can lead to difficulty in interpreting and applying trial outcomes to clinical practice. In particular, the terms ‘viable’ and ‘hibernating’ are commonly applied interchangeably and incorrectly to myocardium that exhibits chronic contractile dysfunction in patients with ischaemic heart disease. The range of inherent differences amongst imaging modalities used to define myocardial health and disease add further challenges to consistent definitions. The results of several large trials have led to renewed discussion about the classification of dysfunctional myocardial segments. This article aims to describe the diverse myocardial pathologies that may affect the myocardium in ischaemic heart disease and cardiomyopathy, and how they may be assessed with non-invasive imaging techniques in order to provide a taxonomy of myocardial dysfunction. PMID:27147609

Integrated Tsunami Database: simulation and identification of seismic tsunami sources, 3D visualization and post-disaster assessment on the shore

NASA Astrophysics Data System (ADS)

Krivorot'ko, Olga; Kabanikhin, Sergey; Marinin, Igor; Karas, Adel; Khidasheli, David

2013-04-01

One of the most important problems of tsunami investigation is the problem of seismic tsunami source reconstruction. Non-profit organization WAPMERR (http://wapmerr.org) has provided a historical database of alleged tsunami sources around the world that obtained with the help of information about seaquakes. WAPMERR also has a database of observations of the tsunami waves in coastal areas. The main idea of presentation consists of determining of the tsunami source parameters using seismic data and observations of the tsunami waves on the shore, and the expansion and refinement of the database of presupposed tsunami sources for operative and accurate prediction of hazards and assessment of risks and consequences. Also we present 3D visualization of real-time tsunami wave propagation and loss assessment, characterizing the nature of the building stock in cities at risk, and monitoring by satellite images using modern GIS technology ITRIS (Integrated Tsunami Research and Information System) developed by WAPMERR and Informap Ltd. The special scientific plug-in components are embedded in a specially developed GIS-type graphic shell for easy data retrieval, visualization and processing. The most suitable physical models related to simulation of tsunamis are based on shallow water equations. We consider the initial-boundary value problem in Ω := {(x,y) ?R2 : x ?(0,Lx ), y ?(0,Ly ), Lx,Ly > 0} for the well-known linear shallow water equations in the Cartesian coordinate system in terms of the liquid flow components in dimensional form Here ?(x,y,t) defines the free water surface vertical displacement, i.e. amplitude of a tsunami wave, q(x,y) is the initial amplitude of a tsunami wave. The lateral boundary is assumed to be a non-reflecting boundary of the domain, that is, it allows the free passage of the propagating waves. Assume that the free surface oscillation data at points (xm, ym) are given as a measured output data from tsunami records: fm(t) := ? (xm, ym,t), (xm,ym ) ?Ω, t ?(Tm1, Tm2), m = 1,2,...,M, M ?N (2) The problem of tsunami source reconstruction (inverse tsunami problem) consists of determining the unknown initial perturbation q(x,y) of the free surface defied in (1) from knowledge of the free surface oscillation data fm(t) given by (2). We present a numerical method to determine the tsunami source using measurements of the height of a passing tsunami wave. Proposed approach based on the weak solution theory for hyperbolic PDEs and adjoint problem method for minimization of the corresponding cost functional 2 J(q) = ?Aq - F? , F = (f1,...,fM ). (3) The adjoint problem is defined to obtain an explicit gradient formula for the cost functional (3). Different numerical algorithms (finite-difference approach and finite volume method) are proposed for the direct as well as adjoint problem. Conjugate gradient algorithm based on explicit gradient formula is used for numerical solution of the inverse problem (1)-(2). This work was partially supported by the Russian Foundation for Basic Research (project No. 12-01-00773) and by SB RAS interdisciplinary project 14 "Inverse Problems and Applications: Theory, Algorithms, Software".

Shear velocity and intrinsic Q structure of the shallow crust in southeastern New England from Rg wave dispersion

NASA Astrophysics Data System (ADS)

Saikia, Chandan K.; Kafka, Alan L.; Gnewuch, Scott C.; McTigue, John W.

1990-06-01

In this study, we analyzed 0.5-2.0 s period Rayleigh waves (Rg) generated by quarry and construction blasting in southern New England (CNE). We investigated group velocity dispersion and attenuation of the observed Rg waves. The paths crossing the Hartford Rift basin (HRB) show an obvious correlation between geology and Rg dispersion. The entire region in the southeastern New England comprising a wide range of geological structures and rock types from the Bronson Hill Anticlinorium to the Avalonian Terrane can be represented as one dispersion region. Therefore the relationship between lateral changes in geologic structures mapped on the surface and Rg dispersion is not as straightforward as might be expected for a best fitting flat-layered model of the shallow crust. The shear wave velocities appear to vary between 2.55 and 3.63 km/s within the upper 2.5 km except for the central HRB where the variation is between 2.12 and 2.7 km/s. Intrinsic Q structure is considered to be the primary means for the loss of energy in the shallow crust and was analyzed by modelling the waveforms of several of the observed seismograms. For this aspect of our study, we used a modal summation of Rayleigh waves assuming a far-field radiation approximation. The observed seismograms were dominated primarily by contributions from the fundamental mode, but higher modes were also included in the synthesis of the waveform. We were unable to model the absolute amplitudes of the waveforms because of the problems with the instrument calibration. It is clear, however, that to predict correct waveforms, the shear wave Q values in the upper few tenths of a kilometer of the crust must be about an order of magnitude smaller than Q values at the depth of 1-3 km which is of order of 100-250.

Twenty-five years of accomplishments of the College of American Pathologists Q-probes program for clinical pathology.

PubMed

Howanitz, Peter J; Perrotta, Peter L; Bashleben, Christine P; Meier, Frederick A; Ramsey, Glenn E; Massie, Larry W; Zimmerman, Roberta L; Karcher, Donald S

2014-09-01

During the past 25 years, the College of American Pathologists' (CAP) Q-Probes program has been available as a subscription program to teach laboratorians how to improve the quality of clinical laboratory services. To determine the accomplishments of the CAP Q-Probes program. We reviewed Q-Probes participant information, study data and conclusions, author information, and program accomplishments. During this time 117 Q-Probes clinical pathology studies were conducted by 54 authors and coauthors, 42,899 laboratories enrolled from 24 countries, 98 peer-reviewed publications occurred and were cited more than 1600 times, and the studies were featured 59 times in CAP Today. The most frequent studies (19) focused on turnaround times for results or products at specific locations (emergency department, operating room, inpatients, outpatients), specific diseases (acute myocardial infarction, urinary tract), availability for specific events such as morning rounds or surgery, a specific result (positive blood cultures), and a method on how to use data for improvement (stat test outliers). Percentile ranking of study participants with better performance provided benchmarks for each study with attributes statistically defined that influenced improved performance. Other programs, such as an ongoing quality improvement program (Q-Tracks), a laboratory competency assessment program, a pathologist certification program, and an ongoing physician practice evaluation program (Evalumetrics), have been developed from Q-Probes studies. The CAP's Q-Probes program has made significant contributions to the medical literature and has developed a worldwide reputation for improving the quality of clinical pathology services worldwide.

Intracranial pressure increases during exposure to a shock wave.

PubMed

Leonardi, Alessandra Dal Cengio; Bir, Cynthia A; Ritzel, Dave V; VandeVord, Pamela J

2011-01-01

Traumatic brain injuries (TBI) caused by improvised explosive devices (IEDs) affect a significant percentage of surviving soldiers wounded in Iraq and Afghanistan. The extent of a blast TBI, especially initially, is difficult to diagnose, as internal injuries are frequently unrecognized and therefore underestimated, yet problems develop over time. Therefore it is paramount to resolve the physical mechanisms by which critical stresses are inflicted on brain tissue from blast wave encounters with the head. This study recorded direct pressure within the brains of male Sprague-Dawley rats during exposure to blast. The goal was to understand pressure wave dynamics through the brain. In addition, we optimized in vivo methods to ensure accurate measurement of intracranial pressure (ICP). Our results demonstrate that proper sealing techniques lead to a significant increase in ICP values, compared to the outside overpressure generated by the blast. Further, the values seem to have a direct relation to a rat's size and age: heavier, older rats had the highest ICP readings. These findings suggest that a global flexure of the skull by the transient shockwave is an important mechanism of pressure transmission inside the brain.

Seismic Full Waveform Modeling & Imaging in Attenuating Media

NASA Astrophysics Data System (ADS)

Guo, Peng

Seismic attenuation strongly affects seismic waveforms by amplitude loss and velocity dispersion. Without proper inclusion of Q parameters, errors can be introduced for seismic full waveform modeling and imaging. Three different (Carcione's, Robertsson's, and the generalized Robertsson's) isotropic viscoelastic wave equations based on the generalized standard linear solid (GSLS) are evaluated. The second-order displacement equations are derived, and used to demonstrate that, with the same stress relaxation times, these viscoelastic formulations are equivalent. By introducing separate memory variables for P and S relaxation functions, Robertsson's formulation is generalized to allow different P and S wave stress relaxation times, which improves the physical consistency of the Qp and Qs modelled in the seismograms.The three formulations have comparable computational cost. 3D seismic finite-difference forward modeling is applied to anisotropic viscoelastic media. The viscoelastic T-matrix (a dynamic effective medium theory) relates frequency-dependent anisotropic attenuation and velocity to reservoir properties in fractured HTI media, based on the meso-scale fluid flow attenuation mechanism. The seismic signatures resulting from changing viscoelastic reservoir properties are easily visible. Analysis of 3D viscoelastic seismograms suggests that anisotropic attenuation is a potential tool for reservoir characterization. To compensate the Q effects during reverse-time migration (RTM) in viscoacoustic and viscoelastic media, amplitudes need to be compensated during wave propagation; the propagation velocity of the Q-compensated wavefield needs to be the same as in the attenuating wavefield, to restore the phase information. Both amplitude and phase can be compensated when the velocity dispersion and the amplitude loss are decoupled. For wave equations based on the GSLS, because Q effects are coupled in the memory variables, Q-compensated wavefield propagates faster than the attenuating wavefield, and introduce unwanted phase shift. Numerical examples show that there are phase (depth) shifts in the Q-compensated RTM images from the GSLS equation. An adjoint-based least-squares reverse-time migration is proposed for viscoelastic media (Q-LSRTM), to compensate the attenuation losses in P and S images. The viscoelastic adjoint operator, and the P and S modulus perturbation imaging conditions are derived using the adjoint-state method and an augmented Lagrangian functional. Q-LSRTM solves the viscoelastic linearized modeling operator for synthetic data, and the adjoint operator is used for back propagating the data residual. Q-LSRTM is capable of iteratively updating the P and S modulus perturbations,in the direction of minimizing data residuals, and attenuation loss is iteratively compensated. A novel Q compensation approach is developed for adjoint seismic imaging by pseudodifferential scaling. With a correct Q model included in the migration algorithm, propagation effects, including the Q effects, can be compensated with the application of the inverse Hessian to the RTM image. Pseudodifferential scaling is used to efficiently approximate the action of the inverse Hessian. Numerical examples indicate that the adjoint RTM images with pseudodifferential scaling approximate the true model perturbation, and can be used as well-conditioned gradients for least-squares imaging.

Mapping the active site helix-to-strand conversion of CxxxxC peroxiredoxin Q enzymes.

PubMed

Perkins, Arden; Gretes, Michael C; Nelson, Kimberly J; Poole, Leslie B; Karplus, P Andrew

2012-09-25

Peroxiredoxins (Prx) make up a family of enzymes that reduce peroxides using a peroxidatic cysteine residue; among these, members of the PrxQ subfamily are proposed to be the most ancestral-like yet are among the least characterized. In many PrxQ enzymes, a second "resolving" cysteine is located five residues downstream from the peroxidatic Cys, and these residues form a disulfide during the catalytic cycle. Here, we describe three hyperthermophilic PrxQ crystal structures originally determined by the RIKEN structural genomics group. We reprocessed the diffraction data and conducted further refinement to yield models with R(free) values lowered by 2.3-7.2% and resolution extended by 0.2-0.3 Å, making one, at 1.4 Å, one of the best resolved peroxiredoxins to date. Comparisons of two matched thiol and disulfide forms reveal that the active site conformational change required for disulfide formation involves a transition of ~20 residues from a pair of α-helices to a β-hairpin and 3(10)-helix. Each conformation has ~10 residues with a high level of disorder providing slack that allows the dramatic shift, and the two conformations are anchored to the protein core by distinct nonpolar side chains that fill three hydrophobic pockets. Sequence conservation patterns confirm the importance of these and a few additional residues for function. From a broader perspective, this study raises the provocative question of how to make use of the valuable information in the Protein Data Bank generated by structural genomics projects but not described in the literature, perhaps remaining unrecognized and certainly underutilized.

Coenzyme Q10 for the treatment of heart failure: a review of the literature

PubMed Central

DiNicolantonio, James J; Bhutani, Jaikrit; McCarty, Mark F; O'Keefe, James H

2015-01-01

Coenzyme Q10 (CoQ10) is an endogenously synthesised and diet-supplied lipid-soluble cofactor that functions in the mitochondrial inner membrane to transfer electrons from complexes I and II to complex III. In addition, its redox activity enables CoQ10 to act as a membrane antioxidant. In patients with congestive heart failure, myocardial CoQ10 content tends to decline as the degree of heart failure worsens. A number of controlled pilot trials with supplemental CoQ10 in heart failure found improvements in functional parameters such as ejection fraction, stroke volume and cardiac output, without side effects. Subsequent meta-analyses have confirmed these findings, although the magnitude of benefit tends to be less notable in patients with severe heart failure, or within the context of ACE inhibitor therapy. The multicentre randomised placebo-controlled Q-SYMBIO trial has assessed the impact of supplemental CoQ10 on hard endpoints in heart failure. A total of 420 patients received either CoQ10 (100 mg three times daily) or placebo and were followed for 2 years. Although short-term functional endpoints were not statistically different in the two groups, CoQ10 significantly reduced the primary long-term endpoint—a major adverse cardiovascular event—which was observed in 15% of the treated participants compared to 26% of those receiving placebo (HR=0.50, CI 0.32 to 0.80, p=0.003). Particularly in light of the excellent tolerance and affordability of this natural physiological compound, supplemental CoQ10 has emerged as an attractive option in the management of heart failure, and merits evaluation in additional large studies. PMID:26512330

Coenzyme Q10 and statins: biochemical and clinical implications.

PubMed

Littarru, Gian Paolo; Langsjoen, Peter

2007-06-01

Statins are drugs of known and undisputed efficacy in the treatment of hypercholesterolemia, usually well tolerated by most patients. In some cases treatment with statins produces skeletal muscle complaints, and/or mild serum CK elevation; the incidence of rhabdomyolysis is very low. As a result of the common biosynthetic pathway Coenzyme Q (ubiquinone) and dolichol levels are also affected, to a certain degree, by the treatment with these HMG-CoA reductase inhibitors. Plasma levels of CoQ10 are lowered in the course of statin treatment. This could be related to the fact that statins lower plasma LDL levels, and CoQ10 is mainly transported by LDL, but a decrease is also found in platelets and in lymphocytes of statin treated patients, therefore it could truly depend on inhibition of CoQ10 synthesis. There are also some indications that statin treatment affects muscle ubiquinone levels, although it is not yet clear to which extent this depends on some effect on mitochondrial biogenesis. Some papers indicate that CoQ10 depletion during statin therapy might be associated with subclinical cardiomyopathy and this situation is reversed upon CoQ10 treatment. We can reasonably hypothesize that in some conditions where other CoQ10 depleting situations exist treatment with statins may seriously impair plasma and possible tissue levels of coenzyme Q10. While waiting for a large scale clinical trial where patients treated with statins are also monitored for their CoQ10 status, with a group also being given CoQ10, physicians should be aware of this drug-nutrient interaction and be vigilant to the possibility that statin drugs may, in some cases, impair skeletal muscle and myocardial bioenergetics.

Inhibition of microRNA-1 attenuates hypoxia/re-oxygenation-induced apoptosis of cardiomyocytes by directly targeting Bcl-2 but not GADD45Beta

PubMed Central

Zhai, Changlin; Tang, Guanmin; Peng, Lei; Hu, Huilin; Qian, Gang; Wang, Shijun; Yao, Jiankang; Zhang, Xiaoping; Fang, Ying; Yang, Shuang; Zhang, Xiumei

2015-01-01

MicroRNAs are small non-coding RNAs that are able to regulate gene expression and play important roles in some biological and pathological processes, including the myocardial ischemia/reperfusion (I/R) injury. Recent findings demonstrated that miR-1 exacerbated I/R-induced injury. This study was to investigate theanti-apoptotic property of miR-1 inhibition and the potential regulatory mechanism. Results showed miR-1 expression reduced in the heart of rats undergoing myocardial I/R and the cardiomyocytes receiving hypoxia/reoxygenation (H/R) injury, but the serum miR-1 expression increased. The targets of miR-1 were predicted by cDNA microarray, and Bcl-2 and GADD45β were selected as candidate targets. Western blot assay and qPCR showed Bcl-2 and GADD45β protein and mRNA expressions increased after I/R injury and H/R injury. Bcl-2 was a direct target of miR-1 as shown in previous studies. Luciferase assay and Western blot assay revealed GADD45β was a direct target of miR-1, and miR-1 suppressed GADD45β expression via binding to its 3’UTR. Furthermore, miR-1 inhibition increased Bcl-2 expression and reduced IA/AAR (infarct area/area at risk) ratio and cell apoptosis in rats undergoing myocardial I/R as well as in cardiomyocytes receiving H/R injury. Importantly, Bcl-2 knockdown restored these consequences following miR-1 inhibition. However, GADD45β knockdown reduced IA/AAR ratio and cell apoptosis in vivo and in vitro, but failed torestore above consequences after miR-1 inhibition. In conclusion miR-1 inhibition protects against H/R-induced apoptosis of myocytes by directly targeting Bcl-2 but not GADD45β. PMID:26692938

Effect and Mechanism of QiShenYiQi Pill on Experimental Autoimmune Myocarditis Rats.

PubMed

Lv, Shichao; Wu, Meifang; Li, Meng; Wang, Qiang; Xu, Ling; Wang, Xiaojing; Zhang, Junping

2016-03-06

To observe the effect of QiShenYiQi pill (QSYQ) on experimental autoimmune myocarditis rats, and to explore its mechanism of action. Lewis rats underwent the injection of myocardial myosin mixed with Freund's complete adjuvant were randomized into 3 groups: model, valsartan, and QSYQ groups. Rats injected with phosphate-buffered saline (PBS) mixed with Freund's complete adjuvant were used as the control group. Rats were euthanized at 4 and 8 weeks, and we weighed rat body mass, heart mass, and left ventricular mass. Myocardium sections were stained with hematoxylin and eosin (H&E) and Masson trichrome. Myocardial TGF-β1 and CTGF protein expression was detected by immunohistochemistry, and myocardial TGF-β1 and CTGF mRNA expression was detected by real-time qPCR. QSYQ reduced HMI and LVMI, as well as the histological score of hearts and CVF, which further decreased over time, and its effect was significantly greater than that of valsartan at 4 and 8 weeks. After 4 weeks, QSYQ inhibited the protein and mRNA expression of TGF-β1 and CTGF, and its effect on lowering CTGF was significantly greater than that of valsartan. In addition, after 8 weeks, QSYQ also inhibited the protein and mRNA expression of CTGF, whereas there was no significant difference in the expression of myocardial TGF-β1. This study provides evidence that QSYQ can improve cardiac remodeling of experimental autoimmune myocarditis rats. It also effectively improved the degree of myocardial fibrosis, which is related to the mechanism of regulation of TGF-β1 CTGF.

Diagnostic and prognostic value of cardiovascular magnetic resonance in non-ischaemic cardiomyopathies

PubMed Central

2012-01-01

Cardiovascular Magnetic Resonance (CMR) is recognised as a valuable clinical tool which in a single scan setting can assess ventricular volumes and function, myocardial fibrosis, iron loading, flow quantification, tissue characterisation and myocardial perfusion imaging. The advent of CMR using extrinsic and intrinsic contrast-enhanced protocols for tissue characterisation have dramatically changed the non-invasive work-up of patients with suspected or known cardiomyopathy. Although the technique initially focused on the in vivo identification of myocardial necrosis through the late gadolinium enhancement (LGE) technique, recent work highlighted the ability of CMR to provide more detailed in vivo tissue characterisation to help establish a differential diagnosis of the underlying aetiology, to exclude an ischaemic substrate and to provide important prognostic markers. The potential application of CMR in the clinical approach of a patient with suspected non-ischaemic cardiomyopathy is discussed in this review. PMID:22857649

On the arbitrary l-wave solutions of the deformed hyperbolic manning-rosen potential including an improved approximation to the orbital centrifugal term

NASA Astrophysics Data System (ADS)

Xu, Chun-Long; Zhang, Min-Cang

2017-01-01

The arbitrary l-wave solutions to the Schrödinger equation for the deformed hyperbolic Manning-Rosen potential is investigated analytically by using the Nikiforov-Uvarov method, the centrifugal term is treated with an improved Greene and Aldrich's approximation scheme. The wavefunctions depend on the deformation parameter q, which is expressed in terms of the Jocobi polynomial or the hypergeometric function. The bound state energy is obtained, and the discrete spectrum is shown to be independent of the deformation parameter q.

Measurements of the S-wave fraction in B 0 → K + π - μ + μ - decays and the B 0 → K ∗(892)0 μ + μ - differential branching fraction

NASA Astrophysics Data System (ADS)

Aaij, R.; Adeva, B.; Adinolfi, M.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Andreassi, G.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Aquines Gutierrez, O.; Archilli, F.; d'Argent, P.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Bel, L. J.; Bellee, V.; Belloli, N.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Bettler, M.-O.; van Beuzekom, M.; Bifani, S.; Billoir, P.; Bird, T.; Birnkraut, A.; Bitadze, A.; Bizzeti, A.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Boettcher, T.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borisyak, M.; Borsato, M.; Bossu, F.; Boubdir, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Braun, S.; Britsch, M.; Britton, T.; Brodzicka, J.; Buchanan, E.; Burr, C.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Campora Perez, D.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; Cauet, Ch.; Cavallero, G.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chatzikonstantinidis, G.; Chefdeville, M.; Chen, S.; Cheung, S.-F.; Chobanova, V.; Chrzaszcz, M.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coquereau, S.; Corti, G.; Corvo, M.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Cruz Torres, M.; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dall'Occo, E.; Dalseno, J.; David, P. N. Y.; Davis, A.; De Aguiar Francisco, O.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Simone, P.; Dean, C.-T.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Demmer, M.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Dijkstra, H.; Dordei, F.; Dorigo, M.; Dosil Suárez, A.; Dovbnya, A.; Dreimanis, K.; Dufour, L.; Dujany, G.; Dungs, K.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Déléage, N.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Farley, N.; Farry, S.; Fay, R.; Ferguson, D.; Fernandez Albor, V.; Ferrari, F.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fleuret, F.; Fohl, K.; Fontana, M.; Fontanelli, F.; Forshaw, D. C.; Forty, R.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Färber, C.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; García Pardiñas, J.; Garra Tico, J.; Garrido, L.; Garsed, P. J.; Gascon, D.; Gaspar, C.; Gavardi, L.; Gazzoni, G.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianì, S.; Gibson, V.; Girard, O. G.; Giubega, L.; Gizdov, K.; Gligorov, V. V.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gorelov, I. V.; Gotti, C.; Grabalosa Gándara, M.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Griffith, P.; Grillo, L.; Grünberg, O.; Gushchin, E.; Guz, Yu.; Gys, T.; Göbel, C.; Hadavizadeh, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heister, A.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hombach, C.; Hulsbergen, W.; Humair, T.; Hushchyn, M.; Hussain, N.; Hutchcroft, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jawahery, A.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kecke, M.; Kelsey, M.; Kenyon, I. R.; Kenzie, M.; Ketel, T.; Khairullin, E.; Khanji, B.; Khurewathanakul, C.; Kirn, T.; Klaver, S.; Klimaszewski, K.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Kozachuk, A.; Kozeiha, M.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krokovny, P.; Kruse, F.; Krzemien, W.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kuonen, A. K.; Kurek, K.; Kvaratskheliya, T.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J.-P.; Leflat, A.; Lefrançois, J.; Lefèvre, R.; Lemaitre, F.; Lemos Cid, E.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Liu, X.; Loh, D.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Lucio Martinez, M.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Lusiani, A.; Lyu, X.; Machefert, F.; Maciuc, F.; Maev, O.; Maguire, K.; Malde, S.; Malinin, A.; Maltsev, T.; Manca, G.; Mancinelli, G.; Manning, P.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marino, P.; Marks, J.; Martellotti, G.; Martin, M.; Martinelli, M.; Martinez Santos, D.; Martinez Vidal, F.; Martins Tostes, D.; Massacrier, L. M.; Massafferri, A.; Matev, R.; Mathad, A.; Mathe, Z.; Matteuzzi, C.; Mauri, A.; Maurin, B.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; Meadows, B.; Meier, F.; Meissner, M.; Melnychuk, D.; Merk, M.; Michielin, E.; Milanes, D. A.; Minard, M.-N.; Mitzel, D. S.; Molina Rodriguez, J.; Monroy, I. A.; Monteil, S.; Morandin, M.; Morawski, P.; Mordà, A.; Morello, M. J.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Mulder, M.; Mussini, M.; Müller, D.; Müller, J.; Müller, K.; Müller, V.; Naik, P.; Nakada, T.; Nandakumar, R.; Nandi, A.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen-Mau, C.; Niess, V.; Nieswand, S.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Oldeman, R.; Onderwater, C. J. G.; Otalora Goicochea, J. M.; Otto, A.; Owen, P.; Oyanguren, A.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Pappenheimer, C.; Parker, W.; Parkes, C.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Pepe Altarelli, M.; Perazzini, S.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Petrov, A.; Petruzzo, M.; Picatoste Olloqui, E.; Pietrzyk, B.; Pikies, M.; Pinci, D.; Pistone, A.; Piucci, A.; Playfer, S.; Plo Casasus, M.; Poikela, T.; Polci, F.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Pomery, G. J.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, E.; Price, J. D.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Punzi, G.; Qian, W.; Quagliani, R.; Rachwal, B.; Rademacker, J. H.; Rama, M.; Ramos Pernas, M.; Rangel, M. S.; Raniuk, I.; Raven, G.; Redi, F.; Reichert, S.; dos Reis, A. C.; Remon Alepuz, C.; Renaudin, V.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Rodriguez Lopez, J. A.; Rodriguez Perez, P.; Rogozhnikov, A.; Roiser, S.; Romanovskiy, V.; Romero Vidal, A.; Ronayne, J. W.; Rotondo, M.; Ruf, T.; Ruiz Valls, P.; Saborido Silva, J. J.; Sagidova, N.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santimaria, M.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schael, S.; Schellenberg, M.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schubert, K.; Schubiger, M.; Schune, M.-H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sergi, A.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Siddi, B. G.; Silva Coutinho, R.; Silva de Oliveira, L.; Simi, G.; Sirendi, M.; Skidmore, N.; Skwarnicki, T.; Smith, E.; Smith, I. T.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Souza, D.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Stefko, P.; Stefkova, S.; Steinkamp, O.; Stenyakin, O.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Sun, L.; Sutcliffe, W.; Swientek, K.; Syropoulos, V.; Szczekowski, M.; Szumlak, T.; T'Jampens, S.; Tayduganov, A.; Tekampe, T.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Tournefier, E.; Tourneur, S.; Trabelsi, K.; Traill, M.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valat, S.; Valenti, G.; Vallier, A.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vecchi, S.; van Veghel, M.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Venkateswaran, A.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Volkov, V.; Vollhardt, A.; Voneki, B.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voß, C.; de Vries, J. A.; Vázquez Sierra, C.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Weiden, A.; Whitehead, M.; Wicht, J.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M. P.; Williams, M.; Williams, T.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wraight, K.; Wright, S.; Wyllie, K.; Xie, Y.; Xing, Z.; Xu, Z.; Yang, Z.; Yin, H.; Yu, J.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zarebski, K. A.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhang, Y.; Zhelezov, A.; Zheng, Y.; Zhokhov, A.; Zhukov, V.; Zucchelli, S.

2016-11-01

A measurement of the differential branching fraction of the decay B 0 → K ∗(892)0 μ + μ - is presented together with a determination of the S-wave fraction of the K + π - system in the decay B 0 → K +π- μ + μ -. The analysis is based on pp-collision data corresponding to an integrated luminosity of 3 fb-1 collected with the LHCb experiment. The measurements are made in bins of the invariant mass squared of the dimuon system, q 2. Precise theoretical predictions for the differential branching fraction of B 0 → K ∗(892)0 μ + μ - decays are available for the q 2 region 1 .1 < q 2 < 6 .0 GeV2 /c 4. In this q 2 region, for the K +π- invariant mass range 796 < m Kπ < 996 MeV /c 2, the S-wave fraction of the K +π- system in B 0 → K +π- μ + μ - decays is found to be {F}S=0.101± 0.017(stat)± 0.009(syst), and the differential branching fraction of B 0 → K ∗(892)0 μ + μ - decays is determined to be dB/d{q}^2=(0.{392}_{-0.019}^{+0.020}(stat)± 0.010(syst)± 0.027(norm))× 1{0}^{-7}{c}^4/{GeV}^2.

Light Scattering Analysis of Irregularly Shaped Dust Particles: A Study Using 3-Dimensional Reconstructions from Focused Ion-Beam (FIB) Tomography and Q-Space Analysis

NASA Astrophysics Data System (ADS)

Ortiz-Montalvo, D. L.; Conny, J. M.

2017-12-01

We study the scattering properties of irregularly shaped ambient dust particles. The way in which they scatter and absorb light has implications for aerosol optical remote sensing and aerosol radiative forcing applications. However, understanding light scattering and absorption by non-spherical particles can be very challenging. We used focused ion-beam scanning electron microscopy and energy-dispersive x-ray spectroscopy (FIB-SEM-EDS) to reconstruct three-dimensional (3-D) configurations of dust particles collected from urban and Asian sources. The 3-D reconstructions were then used in a discrete dipole approximation method (DDA) to determine their scattering properties for a range of shapes, sizes, and refractive indices. Scattering properties where obtained using actual-shapes of the particles, as well as, (theoretical) equivalently-sized geometrical shapes like spheres, ellipsoids, cubes, rectangular prisms, and tetrahedrons. We use Q-space analysis to interpret the angular distribution of the scattered light obtained for each particle. Q-space analysis has been recently used to distinguish scattering by particles of different shapes, and it involves plotting the scattered intensity versus the scattering wave vector (q or qR) on a log-log scale, where q = 2ksin(θ/2), k = 2π/λ, and R = particle effective radius. Results from a limited number of particles show that when Q-space analysis is applied, common patterns appear that agree with previous Q-space studies done on ice crystals and other irregularly shaped particles. More specifically, we found similar Q-space regimes including a forward scattering regime of constant intensity when qR < 1, followed by the Guinier regime when qR ≈ 1, which is then followed by a complex power law regime with a -3 slope regime, a transition regime, and then a -4 slope regime. Currently, Q-space comparisons between actual- and geometric shapes are underway with the objective of determining which geometric shape best represents the angular distribution and magnitude of the scattered light. Current work also focuses on the effects of the imaginary part of the refractive index on the light scattering of our dust particles.

Ten-year fatal and non-fatal myocardial infarction incidence in elderly populations in Spain: the EPICARDIAN cohort study

PubMed Central

Gabriel, Rafael; Alonso, Margarita; Reviriego, Blanca; Muñiz, Javier; Vega, Saturio; López, Isidro; Novella, Blanca; Suárez, Carmen; Rodríguez-Salvanés, Francisco

2009-01-01

Background In Spain, more than 85% of coronary heart disease deaths occur in adults older than 65 years. However, coronary heart disease incidence and mortality in the Spanish elderly have been poorly described. The aim of this study is to estimate the ten-year incidence and mortality rates of myocardial infarction in a population-based large cohort of Spanish elders. Methods A population-based cohort of 3729 people older than 64 years old, free of previous myocardial infarction, was established in 1995 in three geographical areas of Spain. Any case of fatal and non-fatal myocardial infarction was investigated until December 2004 using the "cold pursuit method", previously used and validated by the the WHO-MONICA project. Results Men showed a significantly (p < 0.001) higher cumulative incidence of myocardial infarction (7.2%; 95%CI: 5.94-8.54) than women (3.8%; 95%CI: 3.06-4.74). Although cumulative incidence increased with age (p < 0.05), gender-differences tended to narrow. Adjusted incidence rates were higher in men (957 per 100 000 person-years) than in women (546 per 100 000 person-years) (p < 0.001) and increased with age (p < 0.001). The increase was progressive in women but not in men. Adjusted mortality rates were also higher in men than in women (p < 0.001), being three times higher in the age group of ≥ 85 years old than in the age group of 65-74 years old (p < 0.001). Conclusion Incidence of fatal and non-fatal myocardial infarction is high in the Spanish elderly population. Men show higher rates than women, but gender differences diminish with age. PMID:19778417

[Chatergee syndrome and anesthesia. Apropos of a case].

PubMed

Le Marec, C; Belat, C; Caroff, P; Puidupin, M; Paris, A; Fourel, D; Dumas, P; Le Guern, G

1996-01-01

A combination of complete left bundle branch block (LBBB) and symmetrical negative T waves on the ECG characterizes the Chattergee syndrome. This pattern is infrequently and fortuitously detected in the absence of clinical symptoms. However, when appearing during general anaesthesia, it may lead to diagnostic difficulties to rule out a myocardial ischaemia. One case of this pattern was observed near the end of an otherwise non-complicated cholecystectomy in a ASA II 45 year old man, ECG abnormalities lasted for only a short time. Recovery and outcome were uneventful. Investigations were negative except for an early LBBB during the exercise test. Echocardiography and coronarography were normal. No therapy was given. In such perioperative cases, it is recommended to keep a very cautious attitude and to search for an incipient coronary disease which cannot be completely excluded in some cases.

Taxonomy of segmental myocardial systolic dysfunction.

PubMed

McDiarmid, Adam K; Pellicori, Pierpaolo; Cleland, John G; Plein, Sven

2017-04-01

The terms used to describe different states of myocardial health and disease are poorly defined. Imprecision and inconsistency in nomenclature can lead to difficulty in interpreting and applying trial outcomes to clinical practice. In particular, the terms 'viable' and 'hibernating' are commonly applied interchangeably and incorrectly to myocardium that exhibits chronic contractile dysfunction in patients with ischaemic heart disease. The range of inherent differences amongst imaging modalities used to define myocardial health and disease add further challenges to consistent definitions. The results of several large trials have led to renewed discussion about the classification of dysfunctional myocardial segments. This article aims to describe the diverse myocardial pathologies that may affect the myocardium in ischaemic heart disease and cardiomyopathy, and how they may be assessed with non-invasive imaging techniques in order to provide a taxonomy of myocardial dysfunction. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Cardiology.

Visco-acoustic wave-equation traveltime inversion and its sensitivity to attenuation errors

NASA Astrophysics Data System (ADS)

Yu, Han; Chen, Yuqing; Hanafy, Sherif M.; Huang, Jiangping

2018-04-01

A visco-acoustic wave-equation traveltime inversion method is presented that inverts for the shallow subsurface velocity distribution. Similar to the classical wave equation traveltime inversion, this method finds the velocity model that minimizes the squared sum of the traveltime residuals. Even though, wave-equation traveltime inversion can partly avoid the cycle skipping problem, a good initial velocity model is required for the inversion to converge to a reasonable tomogram with different attenuation profiles. When Q model is far away from the real model, the final tomogram is very sensitive to the starting velocity model. Nevertheless, a minor or moderate perturbation of the Q model from the true one does not strongly affect the inversion if the low wavenumber information of the initial velocity model is mostly correct. These claims are validated with numerical tests on both the synthetic and field data sets.

Welding induced residual stress evaluation using laser-generated Rayleigh waves

NASA Astrophysics Data System (ADS)

Ye, Chong; Zhou, Yuanlai; Reddy, Vishnu V. B.; Mebane, Aaron; Ume, I. Charles

2018-04-01

Welding induced residual stress could affect the dimensional stability, fatigue life, and chemical resistance of the weld joints. Ultrasonic method serves as an important non-destructive tool for the residual stress evaluation due to its easy implementation, low cost and wide application to different materials. Residual stress would result in the ultrasonic wave velocity variation, which is the so called acoustoelastic effect. In this paper, Laser/EMAT ultrasonic technique was proposed to experimentally study the relative velocity variation ΔV/V of Rayleigh wave, which has the potential to evaluate surface/subsurface longitudinal residual stress developed during the Gas Metal Arc Welding process. Broad band ultrasonic waves were excited by pulsed Q-Switched Nd: YAG laser. An electromagnetic acoustic transducer (EMAT) attached to the welded plates was used to capture the Rayleigh wave signals propagating along the weld seam direction. Different time of flight measurements were conducted by varying the distance between the weld seam and Rayleigh wave propagating path in the range of 0 to 45 mm. The maximum relative velocity difference was found on the weld seam. With the increasing distance away from the weld seam, the relative velocity difference sharply decreased to negative value. With further increase in distance, the relative velocity difference slowly increased and approached zero. The distribution of relative velocity variations indicates that tensile stress appears in the melted zone as it becomes compressive near the heat-affected zone.

Brief Report: Eosinophilic Esophagitis as a Cause of Feeding Problems in Autistic Boy. The First Reported Case

ERIC Educational Resources Information Center

Jarocka-Cyrta, Elzbieta; Wasilewska, Jolanta; Kaczmarski, Maciej Gustaw

2011-01-01

Unrecognized gastrointestinal disorders may contribute to the behavioral problems in non-verbal patients, but they are often overlooked since the clinical symptoms are nonspecific. Eosinophilic esophagitis (EE) is a chronic inflammatory disorder manifesting itself predominantly in reflux-type symptoms that do not respond to standard anti-reflux…

Brain function monitoring during off-pump cardiac surgery: a case report

PubMed Central

Zanatta, Paolo; Bosco, Enrico; Di Pasquale, Piero; Nivedita, Agarwal; Valfrè, Carlo; Sorbara, Carlo

2008-01-01

Background Early postoperative stroke is an adverse syndrome after coronary bypass surgery. This report focuses on overcoming of cerebral ischemia as a result of haemodynamic instability during heart enucleation in off-pump procedure. Case presentation A 67 year old male patient, Caucasian race, with a body mass index of 28, had a recent non-Q posterolateral myocardial infarction one month before and recurrent instable angina. His past history includes an uncontrolled hypertension, dyslipidemia, insulin dependent diabetes mellitus, epiaortic vessel stenosis. The patient was scheduled for an off-pump procedure and monitored with bilateral somatosensory evoked potentials, whose alteration signalled the decrement of the cardiac index during operation. The somatosensory evoked potentials appeared when the blood pressure was increased with a pharmacological treatment. Conclusion During the off-pump coronary bypass surgery, a lower cardiac index, predisposes patients, with multiple stroke risk factors, to a reduction of the cerebral blood flow. Intraoperative somatosensory evoked potentials monitoring provides informations about the functional status of somatosensory cortex to reverse effects of brain ischemia. PMID:18706094

On the role of density and attenuation in three-dimensional multiparameter viscoacoustic VTI frequency-domain FWI: an OBC case study from the North Sea

NASA Astrophysics Data System (ADS)

Operto, S.; Miniussi, A.

2018-06-01

3-D frequency-domain full waveform inversion (FWI) is applied on North Sea wide-azimuth ocean-bottom cable data at low frequencies (≤10 Hz) to jointly update vertical wave speed, density and quality factor Q in the viscoacoustic VTI approximation. We assess whether density and Q should be viewed as proxy to absorb artefacts resulting from approximate wave physics or are valuable for interpretation in the presence of soft sediments and gas cloud. FWI is performed in the frequency domain to account for attenuation easily. Multiparameter frequency-domain FWI is efficiently performed with a few discrete frequencies following a multiscale frequency continuation. However, grouping a few frequencies during each multiscale step is necessary to mitigate acquisition footprint and match dispersive shallow guided waves. Q and density absorb a significant part of the acquisition footprint hence cleaning the velocity model from this pollution. Low Q perturbations correlate with low-velocity zones associated with soft sediments and gas cloud. However, the amplitudes of the Q perturbations show significant variations when the inversion tuning is modified. This dispersion in the Q reconstructions is however not passed on the velocity parameter suggesting that cross-talks between first-order kinematic and second-order dynamic parameters are limited. The density model shows a good match with a well log at shallow depths. Moreover, the impedance built a posteriori from the FWI velocity and density models shows a well-focused image with however local differences with the velocity model near the sea bed where density might have absorbed elastic effects. The FWI models are finally assessed against time-domain synthetic seismogram modelling performed with the same frequency-domain modelling engine used for FWI.

Lower Performance in Orientation to Time and Place Associates with Greater Risk of Cardiovascular Events and Mortality in the Oldest Old: Leiden 85-Plus Study.

PubMed

Rostamian, Somayeh; van Buchem, Mark A; Jukema, J Wouter; Gussekloo, Jacobijn; Poortvliet, Rosalinde K E; de Cren, Anton J M; Sabayan, Behnam

2017-01-01

Background: Impairment in orientation to time and place is commonly observed in community-dwelling older individuals. Nevertheless, the clinical significance of this has been not fully explored. In this study, we investigated the link between performance in orientation domains and future risk of cardiovascular events and mortality in a non-hospital setting of the oldest old adults. Methods: We included 528 subjects free of myocardial infarction (Group A), 477 individuals free of stroke/transient ischemic attack (Group B), and 432 subjects free of both myocardial infarction and stroke/transient ischemic attack (Group C) at baseline from the population-based Leiden 85-plus cohort study. Participants were asked to answer five questions related to orientation to time and five questions related to orientation to place. 5-year risks of first-time fatal and non-fatal myocardial infarction, fatal and non-fatal stroke, as well as cardiovascular and non-cardiovascular mortality, were estimated using the multivariate Cox regression analysis. Results: In the multivariable analyses, adjusted for sociodemographic characteristics and cardiovascular risk factors, each point lower performance in "orientation to time" was significantly associated with higher risk of first-time myocardial infarction (hazard ratio [HR] 1.35, 95% confidence interval [CI] 1.09-1.67, P = 0.007), first-time stroke (HR 1.35, 95% CI 1.12-1.64, P = 0.002), cardiovascular mortality (HR 1.28, 95% CI 1.06-1.54, P = 0.009) and non-cardiovascular mortality (HR 1.37, 95% CI 1.20-1.56, P < 0.001). Similarly, each point lower performance in "orientation to place" was significantly associated with higher risk of first-time myocardial infarction (HR 1.67, 95% CI 1.25-2.22, P = 0.001), first-time stroke (HR 1.39, 95% CI 1.05-1.82, P = 0.016), cardiovascular mortality (HR 1.35, 95% CI 1.00-1.82, P = 0.054) and non-cardiovascular mortality (HR 1.45, 95% CI 1.20-1.77, P < 0.001). Conclusions: Lower performance in orientation to time and place in advanced age is independently related to higher risk of myocardial infarction, stroke and mortality. Impaired orientation might be an early sign of covert vascular injuries, putting subjects at greater risk of cardiovascular events and mortality.

Vortices, skyrmions, and chirality waves in frustrated Mott insulators with a quenched periodic array of impurities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayami, Satoru; Lin, Shi -Zeng; Kamiya, Yoshitomo

Finite-Q magnetic instabilities are rather common in frustrated magnets. When the magnetic susceptibility is maximized at multiple-Q vectors related through lattice symmetry operations, exotic magnetic orderings such as vortex and skyrmion crystals may follow. Here, we show that a periodic array of nonmagnetic impurities, which can be realized through charge density wave ordering, leads to a rich phase diagram featuring a plethora of chiral magnetic phases, especially when there is a simple relation between the reciprocal vectors of the impurity superlattice and the magnetic Q vectors. We also investigate the effect of changing the impurity concentration or disturbing the impuritymore » array with small quenched randomness. Lastly, alternative realizations of impurity superlattices are briefly discussed.« less

Vortices, skyrmions, and chirality waves in frustrated Mott insulators with a quenched periodic array of impurities

DOE PAGES

Hayami, Satoru; Lin, Shi -Zeng; Kamiya, Yoshitomo; ...

2016-11-10

Finite-Q magnetic instabilities are rather common in frustrated magnets. When the magnetic susceptibility is maximized at multiple-Q vectors related through lattice symmetry operations, exotic magnetic orderings such as vortex and skyrmion crystals may follow. Here, we show that a periodic array of nonmagnetic impurities, which can be realized through charge density wave ordering, leads to a rich phase diagram featuring a plethora of chiral magnetic phases, especially when there is a simple relation between the reciprocal vectors of the impurity superlattice and the magnetic Q vectors. We also investigate the effect of changing the impurity concentration or disturbing the impuritymore » array with small quenched randomness. Lastly, alternative realizations of impurity superlattices are briefly discussed.« less

Payments for acute myocardial infarction episodes-of-care initiated at hospitals with and without interventional capabilities.

PubMed

Ben-Josef, Gal; Ott, Lesli S; Spivack, Steven B; Wang, Changqin; Ross, Joseph S; Shah, Sachin J; Curtis, Jeptha P; Kim, Nancy; Krumholz, Harlan M; Bernheim, Susannah M

2014-11-01

It is unknown whether hospitals with percutaneous coronary intervention (PCI) capability provide costlier care than hospitals without PCI capability for patients with acute myocardial infarction. The growing number of PCI hospitals and higher rate of PCI use may result in higher costs for episodes-of-care initiated at PCI hospitals. However, higher rates of transfers and postacute care procedures may result in higher costs for episodes-of-care initiated at non-PCI hospitals. We identified all 2008 acute myocardial infarction admissions among Medicare fee-for-service beneficiaries by principal discharge diagnosis and classified hospitals as PCI- or non-PCI-capable on the basis of hospitals' 2007 PCI performance. We added all payments from admission through 30 days postadmission, including payments to hospitals other than the admitting hospital. We calculated and compared risk-standardized payment for PCI and non-PCI hospitals using 2-level hierarchical generalized linear models, adjusting for patient demographics and clinical characteristics. PCI hospitals had a higher mean 30-day risk-standardized payment than non-PCI hospitals (PCI, $20 340; non-PCI, $19 713; P<0.001). Patients presenting to PCI hospitals had higher PCI rates (39.2% versus 13.2%; P<0.001) and higher coronary artery bypass graft rates (9.5% versus 4.4%; P<0.001) during index admissions, lower transfer rates (2.2% versus 25.4%; P<0.001), and lower revascularization rates within 30 days (0.15% versus 0.27%; P<0.0001) than those presenting to non-PCI hospitals. Despite higher PCI and coronary artery bypass graft rates for Medicare patients initially presenting to PCI hospitals, PCI hospitals were only $627 costlier than non-PCI hospitals for the treatment of patients with acute myocardial infarction in 2008. © 2014 American Heart Association, Inc.

Oxygenation-sensitive cardiovascular magnetic resonance in hypertensive heart disease with left ventricular myocardial hypertrophy and non-left ventricular myocardial hypertrophy: Insight from altered mechanics and cardiac BOLD imaging.

PubMed

Chen, Bing-Hua; Wu, Rui; An, Dong-Aolei; Shi, Ruo-Yang; Yao, Qiu-Ying; Lu, Qing; Hu, Jiani; Jiang, Meng; Deen, James; Chandra, Ankush; Xu, Jian-Rong; Wu, Lian-Ming

2018-05-07

BOLD (blood oxygen level dependent) MRI can detect regional condition of myocardial oxygen supply and demand by means of paramagnetic properties. Noninvasive assessment of myocardial oxygenation by BOLD MRI in hypertensive patients with hypertension (HTN) left ventricular myocardial hypertrophy (LVMH) and HTN non-LVMH and its correlation with myocardial mechanics were performed. Prospective. Twenty patients with HTN LVMH, 21 patients with HTN non-LVMH, and 23 normotensive controls were enrolled. Cine imaging, T2* and T1 mapping sequences were achieved at 3.0T. Dedicated T1 mapping, T2*, and cine imaging analysis were performed by two radiologists using cvi42. One-way analysis of variance, Kruskal-Wallis test, Bland-Altman analysis, Pearson's correlation coefficient, Spearman's rank correlation. T2* values of HTN LVMH group were significantly lower versus the controls (23.78 ± 3.09 versus 30.77 ± 2.71; P < 0.001) and HTN non-LVMH group (23.78 ± 3.09 versus 28.64 ± 4.23; P < 0.001). Left ventricular peak circumferential strain were reduced in HTN LVMH patients compared with other two groups (-11.32 [-15.64, -10.3], -16.78 [-19.35, -15.34], and -19.73 [-20.57, -18.73]; P < 0.05); and longitudinal strain of HTN LVMH patients were lower than other two groups (-11.31 ± 2.91, -15.1 ± 3.06, and -18.85 ± 1.85; P < 0.05); radial strain of HTN LVMH patients were also lower than other two groups (25.03 ± 16, 40.95 ± 17.5 and 47.9 ± 10.23; P < 0.05). Extracellular volume correlated with peak circumferential, longitudinal, and radial strain (spearman rho = 0.6, 0.64, and -0.69; P < 0.05), respectively; T2* negatively correlated with peak circumferential and longitudinal strain (spearman rho = -0.43 and -0.49; P < 0.05), respectively. Patients with lower T2* values had significant decreases in myocardial mechanics (P < 0.05). HTN LVMH patients have both impaired myocardial mechanics and decreased T2* values compared with HTN non-LVMH and normotensive groups. BOLD MRI could provide a feasible assessment modality for detecting altered T2* due to the change of de-oxygenated hemoglobin and hence to the change of signal intensity in oxygenation-sensitive images. 1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018. © 2018 International Society for Magnetic Resonance in Medicine.

Mathematics of tsunami: modelling and identification

NASA Astrophysics Data System (ADS)

Krivorotko, Olga; Kabanikhin, Sergey

2015-04-01

Tsunami (long waves in the deep water) motion caused by underwater earthquakes is described by shallow water equations ( { ηtt = div (gH (x,y)-gradη), (x,y) ∈ Ω, t ∈ (0,T ); η|t=0 = q(x,y), ηt|t=0 = 0, (x,y) ∈ Ω. ( (1) Bottom relief H(x,y) characteristics and the initial perturbation data (a tsunami source q(x,y)) are required for the direct simulation of tsunamis. The main difficulty problem of tsunami modelling is a very big size of the computational domain (Ω = 500 × 1000 kilometres in space and about one hour computational time T for one meter of initial perturbation amplitude max|q|). The calculation of the function η(x,y,t) of three variables in Ω × (0,T) requires large computing resources. We construct a new algorithm to solve numerically the problem of determining the moving tsunami wave height S(x,y) which is based on kinematic-type approach and analytical representation of fundamental solution. Proposed algorithm of determining the function of two variables S(x,y) reduces the number of operations in 1.5 times than solving problem (1). If all functions does not depend on the variable y (one dimensional case), then the moving tsunami wave height satisfies of the well-known Airy-Green formula: S(x) = S(0)° --- 4H (0)/H (x). The problem of identification parameters of a tsunami source using additional measurements of a passing wave is called inverse tsunami problem. We investigate two different inverse problems of determining a tsunami source q(x,y) using two different additional data: Deep-ocean Assessment and Reporting of Tsunamis (DART) measurements and satellite altimeters wave-form images. These problems are severely ill-posed. The main idea consists of combination of two measured data to reconstruct the source parameters. We apply regularization techniques to control the degree of ill-posedness such as Fourier expansion, truncated singular value decomposition, numerical regularization. The algorithm of selecting the truncated number of singular values of an inverse problem operator which is agreed with the error level in measured data is described and analysed. In numerical experiment we used conjugate gradient method for solving inverse tsunami problems. Gradient methods are based on minimizing the corresponding misfit function. To calculate the gradient of the misfit function, the adjoint problem is solved. The conservative finite-difference schemes for solving the direct and adjoint problems in the approximation of shallow water are constructed. Results of numerical experiments of the tsunami source reconstruction are presented and discussed. We show that using a combination of two types of data allows one to increase the stability and efficiency of tsunami source reconstruction. Non-profit organization WAPMERR (World Agency of Planetary Monitoring and Earthquake Risk Reduction) in collaboration with Institute of Computational Mathematics and Mathematical Geophysics of SB RAS developed the Integrated Tsunami Research and Information System (ITRIS) to simulate tsunami waves and earthquakes, river course changes, coastal zone floods, and risk estimates for coastal constructions at wave run-ups and earthquakes. The special scientific plug-in components are embedded in a specially developed GIS-type graphic shell for easy data retrieval, visualization and processing. We demonstrate the tsunami simulation plug-in for historical tsunami events (2004 Indian Ocean tsunami, Simushir tsunami 2006 and others). This work was supported by the Ministry of Education and Science of the Russian Federation.

Phencyclidine and Chemical “Stroking”

PubMed Central

Alexander, Ranya L.

1980-01-01

The current wave of drug abuse is but the latest manifestation of the real human need for “stroking.” Drugs which affect the pleasure center of the brain are prime objects of abuse. Phencyclidine (“PCP” or “angel dust”) is a cyclohexylamine which has properties of the amphetamine-stimulants, the narcotic-depressants and the hallucinogens. Previously unrecognized population groups include children less than six years of age and pregnant women and their intoxicated offspring. Successful treatment of present and future patients must be multidisciplinary and will ultimately depend upon a clear understanding of the pharmacology, social psychology, politics, and economics of drugs of abuse. PMID:7191444

Mortality and morbidity due to exposure to outdoor air pollution in Mashhad metropolis, Iran. The AirQ model approach.

PubMed

Miri, Mohammad; Derakhshan, Zahra; Allahabadi, Ahmad; Ahmadi, Ehsan; Oliveri Conti, Gea; Ferrante, Margherita; Aval, Hamideh Ebrahimi

2016-11-01

In the past two decades, epidemiological studies have shown that air pollution is one of the causes of morbidity and mortality. In this study the effect of PM10, PM2.5, NO2, SO2 and O3 pollutants on human health among the inhabitants of Mashhad has been evaluated. To evaluate the health effects due to air pollution, the AirQ model software 3.3.2, developed by WHO European Centre for Environment and Health, was used. The daily data related to the pollutants listed above has been used for the short term health effects (total mortality, cardiovascular and respiratory mortality, hospitalization due to cardiovascular and respiratory diseases, chronic obstructive pulmonary disease and acute myocardial infarction). PM2.5 had the most health effects on Mashhad inhabitants. With increasing in each 10μg/m3, relative risk rate of pollutant concentration for total mortality due to PM10, PM2.5, SO 2 , NO 2 and O 3 was increased of 0.6%, 1.5%, 0.4%, 0.3% and 0.46% respectively and, the attributable proportion of total mortality attributed to these pollutants was respectively equal to 4.24%, 4.57%, 0.99%, 2.21%, 2.08%, and 1.61% (CI 95%) of the total mortality (correct for the non-accident) occurred in the year of study. The results of this study have a good compatibly with other studies conducted on the effects of air pollution on humans. The AirQ software model can be used in decision-makings as a useful and easy tool. Copyright © 2016 Elsevier Inc. All rights reserved.

Mortality among high-risk patients with acute myocardial infarction admitted to U.S. teaching-intensive hospitals in July: a retrospective observational study.

PubMed

Jena, Anupam B; Sun, Eric C; Romley, John A

2013-12-24

Studies of whether inpatient mortality in US teaching hospitals rises in July as a result of organizational disruption and relative inexperience of new physicians (July effect) find small and mixed results, perhaps because study populations primarily include low-risk inpatients whose mortality outcomes are unlikely to exhibit a July effect. Using the US Nationwide Inpatient sample, we estimated difference-in-difference models of mortality, percutaneous coronary intervention rates, and bleeding complication rates, for high- and low-risk patients with acute myocardial infarction admitted to 98 teaching-intensive and 1353 non-teaching-intensive hospitals during May and July 2002 to 2008. Among patients in the top quartile of predicted acute myocardial infarction mortality (high risk), adjusted mortality was lower in May than July in teaching-intensive hospitals (18.8% in May, 22.7% in July, P<0.01), but similar in non-teaching-intensive hospitals (22.5% in May, 22.8% in July, P=0.70). Among patients in the lowest three quartiles of predicted acute myocardial infarction mortality (low risk), adjusted mortality was similar in May and July in both teaching-intensive hospitals (2.1% in May, 1.9% in July, P=0.45) and non-teaching-intensive hospitals (2.7% in May, 2.8% in July, P=0.21). Differences in percutaneous coronary intervention and bleeding complication rates could not explain the observed July mortality effect among high risk patients. High-risk acute myocardial infarction patients experience similar mortality in teaching- and non-teaching-intensive hospitals in July, but lower mortality in teaching-intensive hospitals in May. Low-risk patients experience no such July effect in teaching-intensive hospitals.

[Multicenter evaluation of h-FABP semi-quantitative assay (Cardio Detect) in central laboratory: the point in acute myocardial infarction diagnosis].

PubMed

Lefèvre, G; Fayet, J-M; Graïne, H; Berny, C; Maupas-Schwalm, F; Capolaghi, B; Morin, C

2007-01-01

The diagnostic performance of heart-Fatty Acid Binding Protein (h-FABP) (semi-quantitative CardioDetect test) and cardiac troponin I (TnIc) blood assays were compared in one hundred patients presenting with suspicion of acute coronary syndrome. Final patient diagnosis was "acute myocardial infarction" in 36 cases, "non ST myocardial infarction" in 25 cases and "non ischemic pathologies" in 39 cases. h-FABP results were positive in 26 patients, negative in 57 patients and ambiguous in 17 patients, the latter corresponding to the final diagnosis of "acute myocardial infarction" in 5 cases, "non ST myocardial infarction" in 2 cases and "non ischemic pathologies " in 10 cases. At admission, h-FABP and TnIc exhibiteda sensitivity of 54% an 66%, respectively and a specificity of 86% and 95%, respectively. Positive and negative predictive values were 81% and 64% for h-FABP, respectively and 92% and 75% for cTnI, respectively. h-FABP and cTnI demonstrated a similar diagnostic efficiency if admission delay is less than 4 hours after onset of chest pain (area under ROC curve TnIc = 0.767 +/- 0.091 ; area under ROC curve h-FABP = 0.622 +/- 0.109 ; p = 0.144). On the contrary, cTnI assay demonstrated a better efficiency than h-FABP (p< 0.005) for patients admitted in a delay of 4 to 12 hours after the onset of chest pain. If chosen cTnI cut-off corresponded to the recent consensus definition used for monitoring acute coronary syndrome patients, h-FABP semi-quantitative assay realized within central laboratory did not demonstrated a better diagnostic efficiency than cTnI.

Gender differences in physical activity following acute myocardial infarction in adults: A prospective, observational study.

PubMed

Minges, Karl E; Strait, Kelly M; Owen, Neville; Dunstan, David W; Camhi, Sarah M; Lichtman, Judith; Geda, Mary; Dreyer, Rachel P; Bueno, Héctor; Beltrame, John F; Curtis, Jeptha P; Krumholz, Harlan M

2017-01-01

Aims Despite the benefits of regular physical activity participation following acute myocardial infarction, little is known about gender differences in physical activity among patients after acute myocardial infarction. We described, by gender, physical activity trajectories pre- and post-acute myocardial infarction, and determined whether gender was independently associated with physical activity. Methods and results The Variation in Recovery: Role of Gender on Outcomes of Young AMI patients (VIRGO) study, conducted at 103 US, 24 Spanish, and three Australian hospitals, was designed, in part, to evaluate gender differences in lifestyle behaviors following acute myocardial infarction. We used baseline, one-month, and 12-month data collected from patients aged 18-55 years ( n = 3572). Patients were assigned to American Heart Association-defined levels of physical activity. A generalized estimating equation model was used to account for repeated measures within the same individual over time. Men were more active (≥150 min/wk moderate or ≥75 min/wk vigorous activity) than women at baseline (42% vs 34%), one month (45% vs 34%), and 12 months (48% vs 36%) (all p < 0.0001). Men engaged in a significantly longer duration of activity at each time point. When controlling for all other factors, women had 1.37 times the odds of being less active than men from pre-acute myocardial infarction to 12-months post-acute myocardial infarction (95% confidence interval: 1.21-1.55). Non-white race, non-active workplaces, smoking, diabetes, hypertension, and obesity were also associated independently with being less active over time (all p < 0.05). Conclusions Although activity increased modestly over time, women recovering from acute myocardial infarction were less likely to meet physical activity recommendations than were men. By identifying factors associated with low levels of activity during acute myocardial infarction recovery, targeted interventions can be introduced prior to hospital discharge.

Characterizing differences in mortality at the low end of the fitness spectrum in individuals with cardiovascular disease.

PubMed

Mandic, Sandra; Myers, Jonathan; Oliveira, Ricardo B; Abella, Joshua; Froelicher, Victor F

2010-06-01

A graded but nonlinear relationship exists between fitness and mortality, with the greatest mortality differences occurring between the least-fit (first, Q1) and the next-least-fit (second, Q2) quintiles of fitness. The purpose of this study was to compare clinical characteristics, exercise test responses, and physical activity (PA) patterns in Q1 versus Q2 in patients with cardiovascular disease (CVD). Observational retrospective study. A total of 5101 patients with a history of CVD underwent clinical treadmill testing and were followed up for 9.1+/-5.5 years. Patients were classified into quintiles of exercise capacity measured in metabolic equivalents. Clinical characteristics, treadmill test results, and recreational PA patterns were compared between Q1 (n = 923) and Q2 (n = 929). Q1 had a nearly two-fold increase in age-adjusted relative risk of cardiovascular mortality compared with Q2 (hazard ratio: 3.79 vs. 2.04, P<0.05; reference: fittest quintile). Q1 patients were older, had more extensive use of medications, and were more likely to have a history of typical angina (35 vs. 28%), myocardial infarction (30 vs. 24%), chronic heart failure (25 vs. 14%), claudication (15 vs. 9%) and stroke (9 vs. 6%) compared with Q2 (all comparisons: P<0.05). Recent and lifetime recreational PA was not different between the two groups. Greater severity of disease in the least-fit versus the next-least-fit quintile likely contributes to but cannot fully explain marked differences in mortality rates in CVD patients. To achieve potential survival benefits, our results suggest that unfit CVD patients should engage in exercise programs of sufficient volume and intensity to improve fitness.

Practice-Level Variation in Outpatient Cardiac Care and Association With Outcomes.

PubMed

Clough, Jeffrey D; Rajkumar, Rahul; Crim, Matthew T; Ott, Lesli S; Desai, Nihar R; Conway, Patrick H; Maresh, Sha; Kahvecioglu, Daver C; Krumholz, Harlan M

2016-02-23

Utilization of cardiac services varies across regions and hospitals, yet little is known regarding variation in the intensity of outpatient cardiac care across cardiology physician practices or the association with clinical endpoints, an area of potential importance to promote efficient care. We included 7 160 732 Medicare beneficiaries who received services from 5635 cardiology practices in 2012. Beneficiaries were assigned to practices providing the plurality of office visits, and practices were ranked and assigned to quartiles using the ratio of observed to predicted annual payments per beneficiary for common cardiac services (outpatient intensity index). The median (interquartile range) outpatient intensity index was 1.00 (0.81-1.24). Mean payments for beneficiaries attributed to practices in the highest (Q4) and lowest (Q1) quartile of outpatient intensity were: all cardiac payments (Q4 $1272 vs Q1 $581; ratio, 2.2); cardiac catheterization (Q4 $215 vs Q1 $64; ratio, 3.4); myocardial perfusion imaging (Q4 $253 vs Q1 $83; ratio, 3.0); and electrophysiology device procedures (Q4 $353 vs Q1 $142; ratio, 2.5). The adjusted odds ratios (95% CI) for 1 incremental quartile of outpatient intensity for each outcome was: cardiac surgical/procedural hospitalization (1.09 [1.09, 1.10]); cardiac medical hospitalization (1.00 [0.99, 1.00]); noncardiac hospitalization (0.99 [0.99, 0.99]); and death at 1 year (1.00 [0.99, 1.00]). Substantial variation in the intensity of outpatient care exists at the cardiology practice level, and higher intensity is not associated with reduced mortality or hospitalizations. Outpatient cardiac care is a potentially important target for efforts to improve efficiency in the Medicare population. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Cardiovascular magnetic resonance of myocardial edema using a short inversion time inversion recovery (STIR) black-blood technique: Diagnostic accuracy of visual and semi-quantitative assessment

PubMed Central

2012-01-01

Background The short inversion time inversion recovery (STIR) black-blood technique has been used to visualize myocardial edema, and thus to differentiate acute from chronic myocardial lesions. However, some cardiovascular magnetic resonance (CMR) groups have reported variable image quality, and hence the diagnostic value of STIR in routine clinical practice has been put into question. The aim of our study was to analyze image quality and diagnostic performance of STIR using a set of pulse sequence parameters dedicated to edema detection, and to discuss possible factors that influence image quality. We hypothesized that STIR imaging is an accurate and robust way of detecting myocardial edema in non-selected patients with acute myocardial infarction. Methods Forty-six consecutive patients with acute myocardial infarction underwent CMR (day 4.5, +/- 1.6) including STIR for the assessment of myocardial edema and late gadolinium enhancement (LGE) for quantification of myocardial necrosis. Thirty of these patients underwent a follow-up CMR at approximately six months (195 +/- 39 days). Both STIR and LGE images were evaluated separately on a segmental basis for image quality as well as for presence and extent of myocardial hyper-intensity, with both visual and semi-quantitative (threshold-based) analysis. LGE was used as a reference standard for localization and extent of myocardial necrosis (acute) or scar (chronic). Results Image quality of STIR images was rated as diagnostic in 99.5% of cases. At the acute stage, the sensitivity and specificity of STIR to detect infarcted segments on visual assessment was 95% and 78% respectively, and on semi-quantitative assessment was 99% and 83%, respectively. STIR differentiated acutely from chronically infarcted segments with a sensitivity of 95% by both methods and with a specificity of 99% by visual assessment and 97% by semi-quantitative assessment. The extent of hyper-intense areas on acute STIR images was 85% larger than those on LGE images, with a larger myocardial salvage index in reperfused than in non-reperfused infarcts (p = 0.035). Conclusions STIR with appropriate pulse sequence settings is accurate in detecting acute myocardial infarction (MI) and distinguishing acute from chronic MI with both visual and semi-quantitative analysis. Due to its unique technical characteristics, STIR should be regarded as an edema-weighted rather than a purely T2-weighted technique. PMID:22455461

Bifurcation Culprit Lesions in ST-segment Elevation Myocardial Infarction: Procedural Success and 5-year Outcome Compared With Nonbifurcation Lesions.

PubMed

Salinas, Pablo; Mejía-Rentería, Hernán; Herrera-Nogueira, Raúl; Jiménez-Quevedo, Pilar; Nombela-Franco, Luis; Núñez-Gil, Iván Javier; Gonzalo, Nieves; Del Trigo, María; Pérez-Vizcayno, María José; Quirós, Alicia; Escaned, Javier; Macaya, Carlos; Fernández-Ortiz, Antonio

2017-08-09

We assessed short- and long-term outcomes of primary angioplasty in ST-segment elevation myocardial infarction by comparing bifurcation culprit lesions (BCL) with non-BCL. Observational study with a propensity score matched control group. Among 2746 consecutive ST-segment elevation myocardial infarction patients, we found 274 (10%) patients with BCL. The primary outcome was a composite endpoint including all-cause death, myocardial infarction, coronary artery bypass grafting or target vessel revascularization, assessed at 30-days and 5-years. Baseline characteristics showed no differences after propensity matching (1:1). In the BCL group, the most frequent strategy was provisional stenting of the main branch (84%). Compared with the non-BCL group, the procedures were technically more complex in the BCL group in terms of need for balloon dilatation (71% BCL vs 59% non-BCL; P = .003), longer procedural time (70 ± 29minutes BCL vs 62.8 ± 28.9minutes non-BCL; P = .004) and contrast use (256.2 ± 87.9mL BCL vs 221.1 ± 82.3mL non-BCL; P < .001). Main branch angiographic success was similar (93.4% BCL vs 93.8% non-BCL; P = .86). Thirty-day all-cause mortality was similar between groups: 4.7% BCL vs 5.1% non-BCL; P = .84. At the 5-year follow-up, there were no differences in all-cause death (12% BCL vs 13% non-BCL; P = .95) or the combined event (22% BCL vs 21% non-BCL; P = .43). Primary angioplasty of a BCL was technically more complex; however, main branch angiographic success was similar, and there were no differences in long-term prognosis compared with non-BCL patients. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Usefulness of the admission electrocardiogram to predict long-term outcomes after non-ST-elevation acute coronary syndrome (from the FRISC II, ICTUS, and RITA-3 [FIR] Trials).

PubMed

Damman, Peter; Holmvang, Lene; Tijssen, Jan G P; Lagerqvist, Bo; Clayton, Tim C; Pocock, Stuart J; Windhausen, Fons; Hirsch, Alexander; Fox, Keith A A; Wallentin, Lars; de Winter, Robbert J

2012-01-01

The aim of this study was to evaluate the independent prognostic value of qualitative and quantitative admission electrocardiographic (ECG) analysis regarding long-term outcomes after non-ST-segment elevation acute coronary syndromes (NSTE-ACS). From the Fragmin and Fast Revascularization During Instability in Coronary Artery Disease (FRISC II), Invasive Versus Conservative Treatment in Unstable Coronary Syndromes (ICTUS), and Randomized Intervention Trial of Unstable Angina 3 (RITA-3) patient-pooled database, 5,420 patients with NSTE-ACS with qualitative ECG data, of whom 2,901 had quantitative data, were included in this analysis. The main outcome was 5-year cardiovascular death or myocardial infarction. Hazard ratios (HRs) were calculated with Cox regression models, and adjustments were made for established outcome predictors. The additional discriminative value was assessed with the category-less net reclassification improvement and integrated discrimination improvement indexes. In the 5,420 patients, the presence of ST-segment depression (≥1 mm; adjusted HR 1.43, 95% confidence interval [CI] 1.25 to 1.63) and left bundle branch block (adjusted HR 1.64, 95% CI 1.18 to 2.28) were independently associated with long-term cardiovascular death or myocardial infarction. Risk increases were short and long term. On quantitative ECG analysis, cumulative ST-segment depression (≥5 mm; adjusted HR 1.34, 95% CI 1.05 to 1.70), the presence of left bundle branch block (adjusted HR 2.15, 95% CI 1.36 to 3.40) or ≥6 leads with inverse T waves (adjusted HR 1.22, 95% CI 0.97 to 1.55) was independently associated with long-term outcomes. No interaction was observed with treatment strategy. No improvements in net reclassification improvement and integrated discrimination improvement were observed after the addition of quantitative characteristics to a model including qualitative characteristics. In conclusion, in the FRISC II, ICTUS, and RITA-3 NSTE-ACS patient-pooled data set, admission ECG characteristics provided long-term prognostic value for cardiovascular death or myocardial infarction. Quantitative ECG characteristics provided no incremental discrimination compared to qualitative data. Copyright © 2012 Elsevier Inc. All rights reserved.

Dual-wavelength mid-infrared CW and Q-switched laser in diode end-pumped Tm,Ho:GdYTaO4 crystal

NASA Astrophysics Data System (ADS)

Wang, Beibei; Gao, Congcong; Dou, Renqin; Nie, Hongkun; Sun, Guihua; Liu, Wenpeng; Yu, Haijuan; Wang, Guoju; Zhang, Qingli; Lin, Xuechun; He, Jingliang; Wang, Wenjun; Zhang, Bingyuan

2018-02-01

Dual-wavelength continuous-wave and Q-switched lasers are demonstrated in a Tm,Ho:GdYTaO4 crystal under 790 nm laser diode end pumping for the first time to the best of our knowledge. The laser operates with a dual wavelength at 1949.677 nm and 2070 nm for continuous-wave with a spacing of about 120 nm. The maximum output power is 0.332 W with a pump power of 3 W. By using graphene as the saturable absorber, a passively Q-switched operation is performed with a dual-wavelength at 1950.323 nm and 2068.064 nm with a wavelength interval of about 118 nm. The maximum average output power of the Q-switched laser goes up to 200 mW with a minimum pulse duration of 1.2 µs and a maximum repetition rate of 34.72 kHz.

Compact diode-pumped continuous-wave and passively Q-switched Nd:GYSO laser at 1.07 μm

NASA Astrophysics Data System (ADS)

Lin, Zhi; Huang, Xiaoxu; Lan, Jinglong; Cui, Shengwei; Wang, Yi; Xu, Bin; Luo, Zhengqian; Xu, Huiying; Cai, Zhiping; Xu, Xiaodong; Zhang, Xiaoyan; Wang, Jun; Xu, Jun

2016-08-01

We report diode-pumped continuous-wave (CW) and Q-switched Nd:GYSO lasers using a compact two-mirror linear laser cavity. Single-wavelength laser emissions at 1074.11 nm with 4.1-W power and at 1058.27 nm with 1.47-W power have been obtained in CW mode. The slope efficiencies with respect to the absorbed pump powers are 48.5% and 22.9%, respectively. Wavelength tunability is also demonstrated with range of about 8 nm. Using a MoS2 saturable absorber, maximum average output power up to 410 mW at 1074 nm can be yielded with absorbed pump power 6.41 W and the maximum pulse energy reaches 1.20 μJ with pulse repetition rate of 342.5 kHz and shortest pulse width of 810 ns. The CW laser results represent the best laser performance and the Q-switching also present the highest output power for Q-switched Nd3+ lasers with MoS2 as saturable absorber.

Time From the Beginning of the Right Ventricle Isovolumetric Contraction to the Peak of the S Wave: A New TDI Indicator for the Non-Invasive Estimation of Pulmonary Hypertension.

PubMed

Parsaee, Mozhgan; Ghaderi, Fereshteh; Alizadehasl, Azin; Bakhshandeh, Hooman

2016-08-01

Echocardiography is a key screening tool in the diagnostic algorithm of pulmonary hypertension (PH). In addition, tissue doppler imaging (TDI) is a promising method for the noninvasive estimation of pulmonary artery pressure (PAP). The aim of this study was to validate the accuracy of measuring the time from the beginning of the right ventricular isovolumetric contraction time (RV IVRT) to the peak of the S wave in the TDI of the base of the RV free wall (time to peak or TTP), as an indicator for the non-invasive estimation of pulmonary hypertension. In this diagnostic test study, 60 consecutive patients referred for right heart catheterization (RHC) were enrolled. A pulse-wave TDI was performed before the cardiac catheterization, with a mean interval of 1 hour between the two measurements. The TDI variables, such as the RV IVRT, myocardial performance index (MPI), and the new "time to peak" parameter, were measured at the lateral basal RV free wall. The patients were divided into two sub-groups according to the RHC findings: no-PH (mean PAP < 25 mmHg) and PH (mean PAP ≥ 25 mmHg) groups. Then, we calculated the specificity and sensitivity of the TDI parameters (including the TTP) for the diagnosis of PH. In our study, the TTP showed a significant inverse relationship with the PAP. Based on our results, a TTP of less than 127 ms could be used to predict PH, with a sensitivity and specificity of about 70% (AUC = 0.746 ± 0.064). Based on the results of this study, we suggest the use of a novel "time from the beginning of isovolumetric contraction to the peak of the S wave" (TTP) parameter in the TDI of the base of the RV free wall to predict PH with acceptable accuracy in comparison with RHC.

A family of nonlinear Schrödinger equations admitting q-plane wave solutions

NASA Astrophysics Data System (ADS)

Nobre, F. D.; Plastino, A. R.

2017-08-01

Nonlinear Schrödinger equations with power-law nonlinearities have attracted considerable attention recently. Two previous proposals for these types of equations, corresponding respectively to the Gross-Pitaievsky equation and to the one associated with nonextensive statistical mechanics, are here unified into a single, parameterized family of nonlinear Schrödinger equations. Power-law nonlinear terms characterized by exponents depending on a real index q, typical of nonextensive statistical mechanics, are considered in such a way that the Gross-Pitaievsky equation is recovered in the limit q → 1. A classical field theory shows that, due to these nonlinearities, an extra field Φ (x → , t) (besides the usual one Ψ (x → , t)) must be introduced for consistency. The new field can be identified with Ψ* (x → , t) only when q → 1. For q ≠ 1 one has a pair of coupled nonlinear wave equations governing the joint evolution of the complex valued fields Ψ (x → , t) and Φ (x → , t). These equations reduce to the usual pair of complex-conjugate ones only in the q → 1 limit. Interestingly, the nonlinear equations obeyed by Ψ (x → , t) and Φ (x → , t) exhibit a common, soliton-like, traveling solution, which is expressible in terms of the q-exponential function that naturally emerges within nonextensive statistical mechanics.

Heart attacks and the Newcastle earthquake.

PubMed

Dobson, A J; Alexander, H M; Malcolm, J A; Steele, P L; Miles, T A

To test the hypothesis that stress generated by the Newcastle earthquake led to increased risk of heart attack and coronary death. A natural experiment. People living in the Newcastle and Lake Macquarie local government areas of New South Wales, Australia. At 10.27 a.m. on 28 December 1989 Newcastle was struck by an earthquake measuring 5.6 on the Richter scale. Myocardial infarction and coronary death defined by the criteria of the WHO MONICA Project and hospital admissions for coronary disease before and after the earthquake and in corresponding periods in previous years. Well established, concurrent data collection systems were used. There were six fatal myocardial infarctions and coronary deaths among people aged under 70 years after the earthquake in the period 28-31 December 1989. Compared with the average number of deaths at this time of year this was unusually high (P = 0.016). Relative risks for this four-day period were: fatal myocardial infarction and coronary death, 1.67 (95% confidence interval [Cl]: 0.72, 3.17); non-fatal definite myocardial infarction, 1.05 (95% Cl: 0.05, 2.22); non-fatal possible myocardial infarction, 1.34 (95% Cl: 0.67, 1.91); hospital admissions for myocardial infarction or other ischaemic heart disease, 1.27 (95% Cl: 0.83, 1.66). There was no evidence of increased risk during the following four months. The magnitude of increased risk of death was slightly less than that previously reported after earthquakes in Greece. The data provide weak evidence that acute emotional and physical stress may trigger myocardial infarction and coronary death.

Dietary non enzymatic antioxidant capacity and the risk of myocardial infarction in the Swedish women's lifestyle and health cohort.

PubMed

Hantikainen, Essi; Löf, Marie; Grotta, Alessandra; Trolle Lagerros, Ylva; Serafini, Mauro; Bellocco, Rino; Weiderpass, Elisabete

2018-02-01

Foods rich in antioxidants have been associated with a reduced risk of myocardial infarction. However, findings from randomized clinical trials on the role of antioxidant supplementation remain controversial. It has been suggested that antioxidants interact with each other to promote cardiovascular health. We therefore investigated the association between dietary Non Enzymatic Antioxidant Capacity (NEAC), measuring the total antioxidant potential of the whole diet, and the risk of myocardial infarction. We followed 45,882 women aged 30-49 years and free from cardiovascular diseases through record linkages from 1991 until 2012. Dietary NEAC was assessed by a validated food frequency questionnaire collected at baseline. Total dietary NEAC was categorized into quintiles and multivariable Cox proportional hazard regression models were fitted to estimate hazard ratios (HR) with 95% confidence intervals (CI). During a mean follow-up time of 20.3 years we detected 657 incident cases of myocardial infarction. After adjusting for potential confounders, we found a significant 28% lower risk of myocardial infarction among women in the fourth (HR: 0.72; 95% CI 0.55-0.95) and a 40% lower risk among women in the fifth quintile (HR: 0.60, 95% CI 0.45-0.81) of dietary NEAC compared to women in the first quintile, with a significant trend (p-value < 0.001). Higher dietary NEAC is associated with a lower risk of myocardial infarction in young to middle-aged women. These findings support the hypothesis that dietary antioxidants protect from myocardial infarction and that this effect might be exerted through interactions between antioxidants.

Velocity sensitivity of seismic body waves to the anisotropic parameters of a TTI-medium

NASA Astrophysics Data System (ADS)

Zhou, Bing; Greenhalgh, Stewart

2008-09-01

We formulate the derivatives of the phase and group velocities for each of the anisotropic parameters in a tilted transversely isotropic medium (TTI-medium). This is a common geological model in seismic exploration and has five elastic moduli or related Thomsen parameters and two orientation angles defining the axis of symmetry of the rock. We present two independent methods to compute the derivatives and examine the formulae with real anisotropic rocks. The formulations and numerical computations do not encounter any singularity problem when applied to the two quasi shear waves, which is a problem with other approaches. The two methods yield the same results, which show in a quantitative way the sensitivity behaviour of the phase and the group velocities to all of the elastic moduli or Thomsen's anisotropic parameters as well as the orientation angles in the 2D and 3D cases. One can recognize the dominant (strong effect) and weak (or 'dummy') parameters for the three seismic body-wave modes (qP, qSV, qSH) and their effective domains over the whole range of phase-slowness directions. These sensitivity patterns indicate the possibility of nonlinear kinematic inversion with the three wave modes for determining the anisotropic parameters and imaging an anisotropic medium.