bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiple UPFC damping control scheme using ANN coordinated adaptive controllers
Authors: Ma Tsao‐Tsung 
Published: August 2009

AbstractThis paper presents a novel design of an adaptive damping control scheme using artificial neural network (ANN) coordinated multiple unified power flow controllers (UPFCs). In this study, a centralized global control scheme is proposed in which three UPFCs are first assumed to be strategically installed in the system to achieve a steady state power flow control objective, then utilized to demonstrate the proposed control scheme in enhancing the damping of low frequency electromechanical oscillations exhibited by a three‐area, six‐machine power system. The coordination of controllers is accomplished by a genetic algorithm based tuning process that is based on considering various system operating conditions and minimizing a set of predefined coordinated damping performance indices (CDPI). The task of real‐time adaptation of system uncertainties is carried out using a trained ANN as an adaptive coordinator to achieve the robust control objectives. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Handling occlusions in video‐based augmented reality using depth information
Authors: Zhu Jiejie , Pan Zhigeng , Sun Chao , Chen Wenzhi 
Published: August 2009

AbstractAugmented Reality (AR) composes virtual objects with real scenes in a mixed environment where human–computer interaction has more semantic meanings. To seamlessly merge virtual objects with real scenes, correct occlusion handling is a significant challenge. We present an approach to separate occluded objects in multiple layers by utilizing depth, color, and neighborhood information. Scene depth is obtained by stereo cameras and two Gaussian local kernels are used to represent color, spatial smoothness. These three cues areintelligentlyfused in a probability framework, where the occlusion information can be safely estimated. We apply our method to handle occlusions in video‐based AR where virtual objects are simply overlapped on real scenes. Experiment results show the approach can correctly register virtual and real objects in different depth layers, and provide a spatial‐awareness interaction environment. Copyright © 2009 John Wiley & Sons, Ltd.
Are the Catalytic Properties of Enzymes from Piezophilic Organisms Pressure Adapted?
Authors: Hay Sam , Evans Rhiannon M. , Levy Colin , Loveridge E. Joel , Wang Xi , Leys David , Allemann Rudolf K. , Scrutton Nigel S. 
Published: August 2009

AbstractWe report the crystal structure of dihydrofolate reductase (DHFR) from the psychropiezophilic bacterium Moritella profunda, which was isolated from the deep ocean at 2 °C and 280 bar. The structure is typical of a chromosomal DHFR and we were unable to identify any obvious structural features that would suggest pressure adaptation. In particular, the core regions of the enzyme are virtually identical to those of the DHFR from the mesophile Escherichia coli. The steady‐state rate at pH 9, which is limited by hydride transfer at atmospheric pressure, is roughly constant between 1 and 750 bar, falling at higher pressures. However, the value of KM increases with increasing pressure, and as a result kcat/KM decreases over the entire pressure range studied. Isotope effect studies showed that increasing the pressure causes a change in the rate‐limiting step of the reaction. We therefore see no evidence of pressure adaptation in either the structure or the activity of this enzyme.
Self‐Assembly of a Chiral Lipid Gelator Controlled by Solvent and Speed of Gelation
Authors: Xue Pengchong , Lu Ran , Yang Xinchun , Zhao Li , Xu Defang , Liu Yan , Zhang Hanzhuang , Nomoto Hiroyuki , Takafuji Makoto , Ihara Hirotaka 
Published: August 2009

AbstractGlutamine derivative1with two‐photon absorbing units has been synthesized and was found to show gelation ability in some solvents. Its self‐assembly in the gel phase could be controlled by the solvent and speed of gelation. For example, in DMSO the organogelator self‐assembled into H‐aggregates with weak exciton coupling between the aromatic moieties. On the other hand, in DMSO/diphenyl ether (1:9, v/v) the molecules formed 1D aggregates, but with strong exciton coupling due to the small distance between the chromophores. Moreover, the formation of these two kinds of aggregates could be adjusted by the ratio of DMSO to diphenyl ether. In DMSO/toluene, DMSO/butanol, DMSO/butyl acetate, and DMSO/acetic acid systems similar results were observed. Therefore, conversion of the packing model occurs irrespective of the nature of the solvent. Notably, a unique sign inversion in the CD spectra could be realized by controlling the speed of gelation in the DMSO/diphenyl ether (1:9, v/v) system. It was found that a low speed of gelation induces the gelator to adopt a packing model with strong π–π interactions between the aromatic units. Moreover, the gels, when excited at 800 nm, emit strong green fluorescence and the quantum chemical calculations suggest that intramolecular charge transfer leads to two‐photon absorption of the gelator molecule.
Comparative cardiac effects of hemodialysis and continuous ambulatory peritoneal dialysis
Authors: Alpert M. A. , Van Stone J. , Twardowski Z. J. , Ruder M. A. , Whiting R. B. , Kelly D. L. , Madsen B. R. 
Published: August 2009

AbstractTo assess the comparative cardiac effects of hemodialysis and continous ambulatory peritoneal dialysis (CAPD), we performed M‐mode echocardiography prior to and immediately following hemodialysis on 56 patients and during the dwell phase of CAPD on 39 patients. Hemodialysis produced a significant increse in the mean velocity of circumferential fiber shortening (V̄CF, an index of left ventricular systolic function) in patients with low V̄CF prior to dialysis, but resulted in no significant change in V̄CF in patients with normal predialysis V̄CF. Hemodialysis produced a significant increase in V̄CF in patients with a normal predialysis left ventricular end‐diastolic volume index (LVEDVI), but resulted in no significant change in V̄CF in patients with left ventricular dilatation prior to dialysis. Hemodialysis produced a significant decrease in mean LVEDVI and mean stroke index, but resulted in no significant change in mean cardiac index due to a reflex increase in heart rate. Mean LVEDVI, mean stroke index, and V̄CF values in patients on CAPD were not significantly different from those observed immediately following hemodialysis. Mean cardiac index and mean heart rate were significantly lower in CAPD patients than in posthemodialysis patients. Pericardial effusion was observed in 25% of hemodialysis patients and 5% of CAPD patients (p<0.05). We conclude (1) the effects of hemodialysis on left ventricular performance are variable and depend in part on predialysis left ventricular volume and left ventricular systolic function, (2) except for a lower cardiac index, left ventricular hemodynamics for CAPD patients resemble those of posthemodialysis patients, and (3) pericardial effusion occurs with significantly higher frequency in patients on hemodialysis than in those on CAPD.
Short‐term effect of nifedipine on effort tolerance in patients with angina pectoris
Authors: Flugelman M. Y. , Shefer A. , Halon D. A. , Witt H. , Gotsman M. S. 
Published: August 2009

AbstractThe short‐term effect of oral nifedipine on effort tolerance was tested in 10 patients with effort angina pectoris and a positive effort test (GXT). The patients had four symptom‐limited GXTs, using the Bruce protocol, on each day of the study at 0800, 1000, 1400, and 1800 hours. They received four doses of 10 mg oral nifedipine on one day and four doses of placebo on the other, each dose given half an hour prior to each GXT. Values with nifedipine were compared to values with placebo at the same time during each day. Nifedipine improved effort tolerance by 0.5 ± 0.6 min (p=NS) on the first GXT (mean ± SEM), by 1.2 ± 0.6 min (p=NS) on the second GXT, by 1.0 ± 0.3 min (p < 0.01) on third GXT, and by 1.3 ± 0.3 min (p < 0.01) on the fourth GXT. Improvement of effort tolerance was associated with a fall in resting blood pressure and less ST depression; these changes were statistically significantly only on the fourth GXT, which may indicate a cumulative effect of subsequent doses of nifedipine.
Extracranial mycotic aneurysms in infective endocarditis
Authors: Mansur A. J. , Grinberg M. , Leāto P. P. , Chung C. V. , Stolf N. A. G. , Pileggi F. 
Published: August 2009

AbstractNine of 217 (4.15%) patients with infective endocarditis who were followed from October 1978 to February 1984 had extracranial mycotic aneurysms (MA). Age range of patients was 6–43 years (mean of 24.8 years) and 7 were male. Etiologic agents were Streptococcus viridans (3 cases), Staphylococcus aureus (2 cases), Staphylococcus epidermidis (1 case), and Pseudomonas aeruginosa (1 case). Two patients had negative blood cultures. The MA involved the arteries of the limbs (5 cases), thoracic (3 cases), and abdominal (1 case) arteries. The diagnosis was made by means of physical examination (5 cases), chest roentgenogram (2 cases), ultrasound examination (1 case), and aortography (1 case), at hospital admission (2 cases), early or before antibiotic therapy (2 cases), and from two days to six months after finishing antibiotic therapy (5 cases). All but one patient were operated upon due to MA; bleeding occurred in three cases; surgery was an emergency procedure in one case and performed from 8 to 58 days after the diagnosis of the MA in the others. Signs of infection at surgery were found in one case. In the others, further antibiotic therapy was not administered. There were no limb losses in the peripheral MA. Four patients received surgical treatment for endocarditis. There was one in‐hospital death and another one 6 months later due to heart failure.
Disc dislodgment in björk shiley mitral valve prosthesis: Two successfully operated cases
Authors: Dubernet J. , Irarrézaval M. J. , Urzúaa J. , Maturana G. , Moráan S. , Lema G. , Asenjo F. , Fajuri A. 
Published: August 2009

AbstractTwo patients with Björk Shiley mitral valve replacement had migration and embolization of the occluding disc. One patient suffered migration of the disc a few hours after surgery and the other had a strut fracture with disc translocation six years after the initial operation. Clinical signs in both cases were pulmonary edema, cardiogenic shock, and absence of prosthetic sounds. Both patients were reoperated on an emergency basis, recovering after a complicated postoperative course. They are on functional Class I, 8 and 1 years later, respectively, with their dislodged discs still in the abdominal aorta. The only hope for survival in these patients is emergency reoperation, once the prosthetic mitral valve dysfunction is confirmed.
Recurrent myocardial infarction and unexpected sudden death in a case of d‐loop d‐transposition of the great arteries associated with single coronary artery
Authors: Imaura T. , Nakagawa S. , Koiwaya Y. , Tanaka K. , Saisho K. , Sumiyoshi A. 
Published: August 2009

AbstractA 40‐year‐old man with d‐loop d‐transposition of the great arteries associated with single coronary artery type 3 by Hvass died unexpectedly. Postmortem study demonstrated myocardial infaraction in the posterior portion of the right ventricle and interventricular septum, and complete obstruction of the proximal right coronary artery. The etiology of the unexpected death is discussed.
Left ventricular diastolic and systolic function during isometric exercise: An echocardiographic study
Authors: Bryhn M. , Castenfors J. 
Published: August 2009

AbstractNormal subjects of both sexes between 20 and 63 years were examined with M‐mode echocardiography. Blood pressure (BP), heart rate (HR), and left ventricular (LV) diastolic and systolic function were measured at rest and at the end of a standardized maximal isometric handgrip test. BP and HR increased about 25%. This increase in cardiac work had no significant influence on LV systolic function. Diastolic function (myocardial relaxation and maximum rate of LV filling), however, improved significantly. Isometric handgrip test is a suitable exercise test in combination with M‐mode echocardiography. Studies on LV function during exercise may improve the sensitivity for detection of mild LV dysfunction.
Influence of cardiac function on the diuretic and hemodynamic effects of the loop diuretic piretanide
Authors: Hasenfuss G. , Holubarsch C. , Herzog C. , Knauf H. , Just H. , Spahn H. , Mutschler E. 
Published: August 2009

AbstractThe influence of caridac function on the diuretic and hemodynamic effects of the loop diuretic piretanide was investigated in nine patients with congestive heart failure. The diuretic response to piretanide correlated significantly with the pretreatment cardiac index (r=0.90). Furthermore, a significant correlation was found between the pretreatment fractional sodium excretion and the cardiac index (r=0.85). The fractional sodium excretion is reciprocal to the renal sodium and water reabsorption. No change in the hemodynamics was observed prior to the onset of diuresis. At 120 minutes after administration of piretanide, the reduction of mean pulmonary capillary wedge pressure (r=0.88) and mean right atrial pressure (r=0.80) was significantly related to the diuretic response. We conclude that the reduced diuretic response to piretanide in patients with low cardiac index is due to increased renal sodium and water reabsorption. The hemodynamic changes following the administration of piretanide are dependent on the diuresis.
Variable neurohumoral and hemodynamic responses to exercise in patients with exertional angina: Influence of the severity of coronary artery disease
Authors: Fujita T. , Ajisaka R. , Matsumoto R. , Iida K. , Iida K. , Sugishita Y. , Ito I. , Takeda T. , Akisada M. 
Published: August 2009

AbstractTo assess neurohumoral and hemodynamic responses to exercise in patients with exertional angina, we measured plasma norepinephrine (NE) concentrations in 23 patients with exertional angina (with no heart failure) and compared the results with their coronary arteriographic findings. The 23 patients were divided into two groups: 14 cases with multiple vessel disease (MVD) and 9 cases with one‐vessel disease. At resting state there were no significant differences between the two groups in levels of NE. At maximal exercise there were no significant differences between the groups in increases of heart rate, blood pressure, and rate‐pressure product, but exercise‐induced increase of plasma NE (%) was significantly larger in MVD (131.6 ± 95.4%) (mean±SD) than in one‐vessel disease (69.0±45.3%) (p<0.01). In conclusion, plasma NE responses to exercise differ between patients with multiple vessel disease and patients with one‐vessel disease.
Reliability of standard electrocardiogram in detecting left ventricular asynergy in 315 patients with recent myocardial infarction
Authors: Giannuzzi P. , Giordano A. , Imparato A. , Li Bergolis M. , Tavazzi L. 
Published: August 2009

AbstractThe relationship between asynergy of the left ventricular wall detected by two‐dimensional echocardiography and ECG signs of necrosis (number of Q waves ≥ 40 ms, Wagner's score) was evaluated in 315 patients (NYHA I‐II) 23–90 days after a first Q‐wave myocardial infarction (MI). Poor correlations were found between asynergy and ECG parameters. An ECG anterior MI is an apicoseptal MI by echo (independently of the ECG extent of Q waves) and the ECG is of little or no help in predicting the extent of asynergy to the inferior wall and proximal segments of the septum. An ECG inferior MI is inferoposterior by echo and the ECG has very limited value in predicting the extent of asynergy to the apex and septum. Patients with Q waves in leads II, III, and aVF had more extensive asynergy than those with either 2Q or > 3Q. R/S ≥ 1 in V1 and/or V2 was present in 44% of patients with inferior MI while asynergy of at least one segment of the posterior wall was observed in 94%. In conclusion, standard ECG is sensitive in identifying anterior versus inferior infarct but it is unreliable in predicting the real extent of asynergy of the left ventricle, particularly in inferior infarcts.
Diltiazem and Propranolol Combination for the Treatment of Chronic Stable Angina Pectoris
Authors: O'Hara M. J. , Khurmi N. S. , Bowles M. J. , Raftery E. B. 
Published: August 2009

AbstractTo examine the benefits and risks of combined diltiazem and propranolol therapy, 23 patients who had completed a double‐blind placebo‐controlled cross‐over comparison between diltiazem and propranolol and who continued to develop angina despite treatment were studied. The patients received the previous dose of diltiazem (180 or 360 mg/day) combined with propranolol 120 mg daily for 4 weeks and if they still developed angina on exercise testing, they went on to propranolol 240 mg daily for a further 4 weeks. Efficacy and safety were evaluated by computer‐assisted maximal treadmill tests, ambulatory heart rate monitoring, and resting systolic time intervals at the end of each 4‐week treatment period. Lowdose combination therapy abolished treadmill angina in 6 patients, but 2 patients had to be withdrawn. The highdose combination abolished treadmill angina in 5 of 15 patients. The exercise time and 1‐mm ST depression time increased with each increment of combination therapy in patients on both doses of diltiazem. The resting, maximal, and ambulatory heart rates progressively decreased with each increment of combined therapy. Left ventricular function, as evaluated clinically and by the systolic time intervals, was not impaired, but severe sinus bradycardia (heart rate <40 beats/min) appeared in 3 patients. Two died during 6 months of follow‐up. Only 11 of the 23 patients completed 6 months of combined therapy without an adverse reaction. Although combined dilitiazem and propranolol therapy relieved angina and increased exercise tolerance in patients refractory to single drug therapy, it should be used with caution in such patients, since bradycardia can pose serious problems.
Myocardial bridging of coronary arteries associated with an impending acute myocardial infarction
Authors: Bestetti R. B. , Finzi L. A. , Amaral F. T. V. , Secches A. L. , Oliveira J. S. M. 
Published: August 2009

AbstractA 57‐year‐old woman developed severe substernal chest pain radiating to the left arm accompanied by pallor and marked diaphoresis. These symptoms appeared at rest, lasted 45 minutes, and terminated spontaneously. The patient had been treated for mild hypertension during the last 6 months. An ECG tracing obtained at the beginning of treatment was unremarkable. However, an ECG tracing recorded shortly after the end of the symptoms showed T‐wave inversion in all anterior leads. Coronary arteriography was then performed and showed no fixed obstructive coronary artery disease. Nonetheless, a lengthened and constricted myocardial bridging of both the left anterior descending coronary artery and its major diagonal branch was detected. Also, the left anterior descending coronary artery was observed to be very short, terminating before the cardiac apex. The left ventricle was hypertrophied. The patient was treated with a beta‐blocking agent which eliminated all symptoms. An ECG tracing obtained about three months after the onset of the clinical picture was normal. Our findings suggest that marked myocardial ischemia at rest does occur in patients having myocardial bridges under special circumstances, such as lengthened and constricted myocardial bridging of a short coronary artery which supplies a hypertrophied ventricle. This anomaly should be taken into account as a possible cause of a threatened myocardial infarction, which may be successfully treated with a beta‐blocking agent.
Pulmonary vascular disease in secundum atrial septal defect in childhood: An unusual evolution
Authors: Dupuis C. , Vaksmann G. , Mycinski C. , Rey C. 
Published: August 2009

AbstractReported is a case of a 16‐month‐old girl with an isolated atrial septal defect in whom severe pulmonary hypertension has developed in 26 months in spite of an important functional gradient across the pulmonic valves at a first catheterization. Individual susceptibility to an increased pulmonary blood flow is evoked.
Plasma atrial peptide concentration during acute changes in cardiac filling pressure induced by a contrast agent
Authors: Porter C. B. , Gumprecht E. , Geer P. G. , Goetz K. L. 
Published: August 2009

AbstractLeft ventricular end‐diastolic pressure and the concentration of atrial peptides in plasma were measured before and after the administration of contrast material into the left ventricle of 12 patients during cardiac catheterization. A positive relationship between changes in left ventricular end‐diastolic pressure and the circulating level of atrial peptides was found in all 12 patients. Increases in plasma atrial peptide levels were detected within less than one minute after injection of the contrast agent. We conclude that the release of atrial peptides in the human is modulated rapidly by changes in atrial pressure. The rapid release of peptides from the atria in response to an increase in atrial pressure, coupled with evidence that atrial peptides reduce cardiac filling pressure, is consistent with the possibility that the atrial peptides may serve as part of a negative feedback system that enables the heart to influence its own filling pressure.
Programmed ventricular stimulation in coronary artery disease and dilated cardiomyopathy: Influence of the underlying heart disease on the results of electrophysiologic testing
Authors: Gonska B.‐D. , Bethge K.‐P. , Kreuzer H. 
Published: August 2009

AbstractIn order to evaluate the clinical and prognostic significance of programmed ventricular stimulation (PVS), 100 patients were investigated. Twenty‐four of 51 patients with coronary artery disease and 22 out of 49 with dilated cardiomyopathy had clinical ventricular tachycardia (VT). The study protocol included 24‐h Holter ECG, cardiac catherterization and angiography, and PVS employing 1 and 2 premature extrastimuli and incremental pacing. In patients with coronary artery disease, VT was induced in 67% with prior VT and in 18% without such episodes (p<0.01). In dilated cardiomyopathy, however, patients with and without clinical VT did not differ with regard to VT inducibility (18% vs. 15%, NS). The inducibility of monomorphic sustained VT—most frequently induced in VT patients—was significantly higher in patients with coronary artery disease (p<0.05). Polymorphic nonsustained VT (in both coronary artery disease and dilated cardiomyopathy) was only initiated in patients without clinical VT. In patients with coronary artery disease, left ventricular ejction fraction could be correlated to clinical arrhythmia (p<0.001), while induced VT could only be correlated to depressed left ventricular function in patients with left ventricular aneurysm. Neither clinical nor induced VT could be correlated to left ventricular ejection fraction in patients with dilated cardiomyopathy. During a mean follow‐up of 21 months, 7 patients died from sudden cardiac death. Six of them had clinical VT, but in only 1 patient with coronary artery disease was VT initiated. There was no apparent difference in the antiarrhythmic therapy of the patients with sudden death with respect to the surviving population. In conclusion, the response to PVS with the stimulation protocol applied is different in patients with coronary artery disease and dilated cardiomyopathy. The prognostic significance of the results obtained from PVS remains uncertain.