Classification of heart valve condition using acoustic measurements

Energy Technology Data Exchange (ETDEWEB)

Clark, G. [Lawrence Livermore National Lab., CA (United States)

1994-11-15

Prosthetic heart valves and the many great strides in valve design have been responsible for extending the life spans of many people with serious heart conditions. Even though the prosthetic valves are extremely reliable, they are eventually susceptible to long-term fatigue and structural failure effects expected from mechanical devices operating over long periods of time. The purpose of our work is to classify the condition of in vivo Bjork-Shiley Convexo-Concave (BSCC) heart valves by processing acoustic measurements of heart valve sounds. The structural failures of interest for Bscc valves is called single leg separation (SLS). SLS can occur if the outlet strut cracks and separates from the main structure of the valve. We measure acoustic opening and closing sounds (waveforms) using high sensitivity contact microphones on the patient`s thorax. For our analysis, we focus our processing and classification efforts on the opening sounds because they yield direct information about outlet strut condition with minimal distortion caused by energy radiated from the valve disc.

Should patients with Björk-Shiley valves undergo prophylactic replacement?

Science.gov (United States)

Birkmeyer, J D; Marrin, C A; O'Connor, G T

1992-08-29

About 85,000 patients have undergone replacement of diseased heart valves with prosthetic Björk-Shiley convexo-concave (CC) valves. These valves are prone to fracture of the outlet strut, which leads to acute valve failure that is usually fatal. Should patients with these valves undergo prophylactic replacement to avoid fracture? The incidence of strut fracture varies between 0% and 1.5% per year, depending on valve opening angle (60 degrees or 70 degrees), diameter (less than 29 mm or greater than or equal to 29 mm), and location (aortic or mitral). Other factors include the patient's life expectancy and the expected morbidity and mortality associated with reoperation. We have used decision analysis to identify the patients most likely to benefit from prophylactic reoperation. The incidence of outlet strut fracture was estimated from the data of three large studies on CC valves, and stratified by opening angle, diameter, and location. A Markov decision analysis model was used to estimate life expectancy for patients undergoing prophylactic valve replacement and for those not undergoing reoperation. Prophylactic valve replacement does not benefit patients with CC valves that have low strut fracture risks (60 degrees aortic valves and less than 29 mm, 60 degrees mitral valves). For most patients with CC valves that have high strut fracture risks (greater than or equal to 29 mm, 70 degrees CC), prophylactic valve replacement increases life expectancy. However, elderly patients with such valves benefit from prophylactic reoperation only if the risk of operative mortality is low. Patient age and operative risk are most important in recommendations for patients with CC valves that have intermediate strut fracture risks (less than 29 mm, 70 degrees valves and greater than or equal to 29 mm, 60 degrees mitral valves). For all patients and their doctors facing the difficult decision on whether to replace CC valves, individual estimates of operative mortality risk that

[Late complications following Björk-Shiley and St. Jude Medical heart valve replacement].

Science.gov (United States)

Horstkotte, D; Körfer, R; Budde, T; Haerten, K; Schulte, H D; Bircks, W; Loogen, F

1983-05-01

Valve-related complications after Björk-Shiley mitral (n = 475), aortic (n = 424), or mitral-aortic implantation (n = 119) were compared to complications after St. Jude mitral (n = 173), aortic (n = 152), and St. Jude mitral and aortic (n = 63) replacements. The 1,018 consecutive patients with Björk-Shiley valves had been operated upon between 1974 and 1982, those with St. Jude valves between 1978 and 1982. All patients were placed on anticoagulant therapy with phenprocoumon early after operation and no significant intergroup differences in the effectiveness of the anticoagulant therapy were found. At a comparable follow-up time of approximately 23 months, 24 major thromboembolic episodes were observed after Björk-Shiley mitral (BSM) and 3 after St. Jude mitral valve implantation (SJM), corresponding to a thromboembolic rate of 2.82/100 patient years with BSM and 0.93/100 patient years with SJM. After aortic valve replacements, 1.93 events in 100 patient years occurred after Björk-Shiley aortic (BSA) and 0.73 after St. Jude aortic implantation (SJA). In patients with double valve replacements, these rates were 3.2 (BSM + BSA) and 0.88 (SJM + SJA), respectively. The cerebral vessels were involved in 52% and the arteries of the extremities in 22% of these major events. Six Björk-Shiley prostheses had to be replaced because of valve thrombosis. The overall incidence of severe hemorrhagic complications was 2.94/100 patient years in BSM and 1.79 in SJM. After aortic valve replacement, we found rates of 1.80/100 patient years (BSA) and 2.57/100 patient years (SJA), respectively. Intravascular hemolysis no longer seems to be a significant clinical problem. However, indications of red cell damage after heart valve replacement were significantly greater in patients with perivalvular leakage, valve thrombosis, or dysfunction than in those with normally functioning prostheses. Reoperations were necessary because of valve thrombosis (0.46%), perivalvular leakage (2

Bjork-Shiley convexoconcave valves: Susceptibility artifacts at brain MR imaging and mechanical valve fractures

NARCIS (Netherlands)

van Gorp, Maarten J.; van der Graaf, Yolanda; de Mol, Bas A. J. M.; Bakker, Chris J. G.; Witkamp, Theo D.; Ramos, Lino M. P.; Mali, Willem P. T. M.

2004-01-01

PURPOSE: To assess the relationship between heart valve history and susceptibility artifacts at magnetic resonance (MR) imaging of the brain in patients with Bjork-Shiley convexoconcave (BSCC) valves. MATERIALS AND METHODS: MR images of the brain were obtained in 58 patients with prosthetic heart

Late complications in patients with Björk-Shiley and St. Jude Medical heart valve replacement.

Science.gov (United States)

Horstkotte, D; Körfer, R; Seipel, L; Bircks, W; Loogen, F

1983-09-01

Valve-related complications after Björk-Shiley mitral valve implantation (n = 475), aortic valve implantation (n = 424), or mitral-aortic valve implantation (n = 119) were compared with those after St. Jude Medical mitral valve replacement (n = 173), aortic valve replacement (n = 152), or mitral-aortic valve replacement (n = 69). All patients were placed on anticoagulant therapy with phenprocoumon early after operation. All patients had a comparable follow-up time of approximately 23 months, which showed that cumulative thromboembolic rates were significantly higher after St. Jude valve implantation than after Björk-Shiley valve implantation. Reoperations were necessary because of valve thrombosis (0.46%), perivalvular leakage (2.2%), or prosthetic valve endocarditis with perivalvular regurgitation (0.46%). One Björk-Shiley mitral valve prosthesis had to be replaced because of fracture of the outlet strut. Without significant intergroup differences, hemorrhage due to anticoagulant treatment was the most frequent complication. Thromboembolic complications were significantly more frequent after Björk-Shiley mitral, aortic, and double valve replacements than after St. Jude valve implantation. This may lead to consideration of changes in the prophylaxis of thrombus formations in the St. Jude valve, especially in aortic valve replacements, in patients with sinus rhythm.

Coronary artery assessment by multidetector computed tomography in patients with prosthetic heart valves

International Nuclear Information System (INIS)

Habets, Jesse; Mali, Willem P.T.M.; Budde, Ricardo P.J.; Brink, Renee B.A. van den; Uijlings, Ruben; Spijkerboer, Anje M.; Chamuleau, Steven A.J.

2012-01-01

Patients with prosthetic heart valves may require assessment for coronary artery disease. We assessed whether valve artefacts hamper coronary artery assessment by multidetector CT. ECG-gated or -triggered CT angiograms were selected from our PACS archive based on the presence of prosthetic heart valves. The best systolic and diastolic axial reconstructions were selected for coronary assessment. Each present coronary segment was scored for the presence of valve-related artefacts prohibiting coronary artery assessment. Scoring was performed in consensus by two observers. Eighty-two CT angiograms were performed on a 64-slice (n = 27) or 256-slice (n = 55) multidetector CT. Eighty-nine valves and five annuloplasty rings were present. Forty-three out of 1160 (3.7%) present coronary artery segments were non-diagnostic due to valve artefacts (14/82 patients). Valve artefacts were located in right coronary artery (15/43; 35%), left anterior descending artery (2/43; 5%), circumflex artery (14/43; 32%) and marginal obtuse (12/43; 28%) segments. All cobalt-chrome containing valves caused artefacts prohibiting coronary assessment. Biological and titanium-containing valves did not cause artefacts except for three specific valve types. Most commonly implanted prosthetic heart valves do not hamper coronary assessment on multidetector CT. Cobalt-chrome containing prosthetic heart valves preclude complete coronary artery assessment because of severe valve artefacts. circle Most commonly implanted prosthetic heart valves do not hamper coronary artery assessment circle Prosthetic heart valve composition determines the occurrence of prosthetic heart valve-related artefacts circle Bjoerk-Shiley and Sorin tilting disc valves preclude diagnostic coronary artery segment assessment. (orig.)

Strut fracture and disc embolization of a Björk-Shiley mitral valve prosthesis: localization of embolized disc by computerized axial tomography.

Science.gov (United States)

Larrieu, A J; Puglia, E; Allen, P

1982-08-01

The case of a patient who survived strut fracture and embolization of a Björk-Shiley mitral prosthetic disc is presented. Prompt surgical treatment was directly responsible for survival. In addition, computerized axial tomography of the abdomen aided in localizing and retrieving the embolized disc, which was lodged at the origin of the superior mesenteric artery. A review of similar case reports from the literature supports our conclusions that the development of acute heart failure and absent or muffled prosthetic heart sounds in a patient with a Björk-Shiley prosthetic heart valve inserted prior to 1978 should raise the possibility of valve dysfunction and lead to early reoperation.

Correctness of multi-detector-row computed tomography for diagnosing mechanical prosthetic heart valve disorders using operative findings as a gold standard

Energy Technology Data Exchange (ETDEWEB)

Tsai, I.Chen [Taichung Veterans General Hospital, Department of Radiology, Taichung (China); Institute of Clinical Medicine and Faculty of Medicine, National Yang-Ming University, Taipei (China); Lin, Yung-Kai; Chang, Yen; Wang, Chung-Chi; Hsieh, Shih-Rong; Wei, Hao-Ji; Tsai, Hung-Wen [Taichung Veterans General Hospital, Section of Cardiovascular Surgery, Cardiovascular Center, Taichung (China); Fu, Yun-Ching; Jan, Sheng-Ling [Institute of Clinical Medicine and Faculty of Medicine, National Yang-Ming University, Taipei (China); Taichung Veterans General Hospital, Section of Pediatric Cardiology, Department of Pediatrics, Taichung (China); Wang, Kuo-Yang [Taichung Veterans General Hospital, Section of General Cardiology, Cardiovascular Center, Taichung (China); Chung-Shan Medical University, Department of Medicine, Taichung (China); Chen, Min-Chi; Chen, Clayton Chi-Chang [Taichung Veterans General Hospital, Department of Radiology, Taichung (China); Central Taiwan University of Science and Technology, Department of Radiological Technology, Taichung (China)

2009-04-15

The purpose was to compare the findings of multi-detector computed tomography (MDCT) in prosthetic valve disorders using the operative findings as a gold standard. In a 3-year period, we prospectively enrolled 25 patients with 31 prosthetic heart valves. MDCT and transthoracic echocardiography (TTE) were done to evaluate pannus formation, prosthetic valve dysfunction, suture loosening (paravalvular leak) and pseudoaneurysm formation. Patients indicated for surgery received an operation within 1 week. The MDCT findings were compared with the operative findings. One patient with a Bjoerk-Shiley valve could not be evaluated by MDCT due to a severe beam-hardening artifact; thus, the exclusion rate for MDCT was 3.2% (1/31). Prosthetic valve disorders were suspected in 12 patients by either MDCT or TTE. Six patients received an operation that included three redo aortic valve replacements, two redo mitral replacements and one Amplatzer ductal occluder occlusion of a mitral paravalvular leak. The concordance of MDCT for diagnosing and localizing prosthetic valve disorders and the surgical findings was 100%. Except for images impaired by severe beam-hardening artifacts, MDCT provides excellent delineation of prosthetic valve disorders. (orig.)

Fracture and embolization of a Björk-Shiley disc. Fatal failure of a prosthetic mitral valve.

Science.gov (United States)

Norenberg, D D; Evans, R W; Gundersen, A E; Abellera, R M

1977-12-01

A case of fracture of the disc occluder of a Bjork-Shiley mitral prosthesis with embolization of the disc fragments to distal aorta is presented. The possibility of valve dysfunction and the diagnostic value of echocardiography should be considered whenever acute heart failure occurs in a patient with an artificial valve.

Velocity and shear stress distribution downstream of mechanical heart valves in pulsatile flow.

Science.gov (United States)

Giersiepen, M; Krause, U; Knott, E; Reul, H; Rau, G

1989-04-01

Ten mechanical valves (TAD 27 mm): Starr-Edwards Silastic Ball, Björk-Shiley Standard, Björk-Shiley Concave-Convex, Björk-Shiley Monostrut, Hall-Kaster (Medtronic-Hall), OmniCarbon, Bicer Val, Sorin, Saint-Jude Medical and Hemex (Duromedics) are investigated in a comparative in vitro study. The velocity and turbulent shear stress profiles of the valves were determined by Laser Doppler anemometry in two different downstream axes within a model aortic root. Depending on the individual valve design, velocity peaks up to 1.5 m/s and turbulent shear stress peaks up to 150 N/m2 were measured during the systolic phase. These shear stress peaks mainly occurred in areas of flow separation and intense momentum exchange. Directly downstream of the valves (measuring axis 0.55.dAorta) turbulent shear stress peaks occurred at peak systole and during the deceleration phase, while in the second measuring axis (1.5.dAorta) turbulence levels were lower. Shear stress levels were high at the borders of the fluid jets. The results are discussed from a fluid-dynamic point of view.

Noninvasive radioisotopic technique for detection of platelet deposition in mitral valve prosthesis and renal microembolism in dogs

International Nuclear Information System (INIS)

Dewanjee, M.K.; Kaye, M.P.; Fuster, V.; Rao, S.A.

1980-01-01

At 24 hrs after implantation of Bjoerk-Shiley mitral prosthesis in 5 dogs, in vivo images were obtained with a gamma camera after intravenous administration (0.5-0.6 mCi) one hour postoperatively of autologous Indium-111-labeled platelets. The site of platelet deposition in the teflon ring and perivascular damaged cardiac tissue is clearly delineated in the scintiphoto. In vitro biodistribution (mean % +/- SD of injected dose) at 24 hrs after injection of the 5 implanted and 7 normal dogs performed with a gamma counter demonstrated that (45.1 +/- 10.6)% and (0.7 +/- 0.4)% were in blood and kidneys in normal dogs and (28.5 +/- 6.8)%, (1.6 +/- 0.6)%, (0.3 +/- 0.1)%, and (0.2 +/- 0.1)% were in blood, kidneys, teflon rings, and perivascular damaged cardiac tissue, respectively. The strut and pyrolytic carbon-coated disc retained only (0.0033 +/- 0.0004)% and (0.0031 +/- 0.0003)%, respectively. There was a 2.3-fold increase of labeled platelets in kidneys of implanted dogs due to renal trapping of microembolism. Also, three- to fivefold increase in ratios of lung, brain, cardiac, and skeletal muscle to blood indicates that internal organs and whole body work as filter for microembolism generated by cardiovascular surgery and mitral prosthesis. Twenty percent of the administered platelets are consumed in surgical repair of damaged tissue. Indium-111-labeled platelets thus provide a sensitive marker for noninvasive imaging of Bjoerk-Shiley mitral prosthesis, thromboembolism after implantation of prosthetic device, and in vitro quantitation of surgical consumption

Twenty-five-year experience with the Björk-Shiley convexoconcave heart valve: a continuing clinical concern.

Science.gov (United States)

Blot, William J; Ibrahim, Michel A; Ivey, Tom D; Acheson, Donald E; Brookmeyer, Ron; Weyman, Arthur; Defauw, Joseph; Smith, J Kermit; Harrison, Donald

2005-05-31

The first Björk-Shiley convexoconcave (BSCC) prosthetic heart valves were implanted in 1978. The 25th anniversary provided a stimulus to summarize the research data relevant to BSCC valve fracture, patient management, and current clinical options. Published and unpublished data on the risks of BSCC valve fracture and replacement were compiled, and strategies for identifying candidates for prophylactic valve reoperation were summarized. By December 2003, outlet strut fractures (OSFs), often with fatal outcomes, had been reported in 633 BSCC valves (0.7% of 86,000 valves implanted). Fractures still continue to occur, but average rates of OSFs in 60 degrees valves are now valve characteristics, especially valve angle and size, with weaker effects associated with other manufacturing variables. OSF risks are mildly lower among women than men but decline sharply with advancing age. The risks of valve replacement typically greatly exceed those of OSF. By comparing individualized estimated risks of OSF versus valve replacement, guidelines have been developed to identify the small percentage of BSCC patients (mostly younger men) who would be expected to have a gain in life expectancy should reoperative surgery be performed. Twenty-five years after the initial BSCC valve implants, fractures continue to occur. Continued monitoring of BSCC patients is needed to track and quantify risks and enable periodic updating of guidelines for patients and their physicians.

[Sudden and fatal malfunction of a Björk-Shiley prosthesis in mitral position due to rupture of the ventricular bracket and disk embolization].

Science.gov (United States)

Casarotto, D; Motta, A; Fabbri, A; Pugliese, P; Muneretto, C; Zanini, M; Sheiban, I

1985-04-01

Mechanical complications of prosthetic valves are increasing. The following report describes a case of fracture of a Björk-Shiley mitral prosthetic strut with dislogment of the valve occluder into the thoracic aorta. At the reoperation a new prosthesis was implanted but the patient died of acute heart failure. The diagnosis of valve disfunction must be made non invasively, because the time required for cardiac catherization usually constitutes a lethal delay. The only hope for survival is prompt surgical treatment.

Thromboembolism and mechanical heart valves : A randomized study revisited

NARCIS (Netherlands)

Kuntze, CEE; Blackstone, EH; Ebels, T

Background. This study was designed to revise and substantiate previous inferences, based on short-term follow-up, about differences in the incidence of anticoagulant-related events after heart valve replacement among patients who had been randomly assigned to receive either a Bjork-Shiley,

[Minor strut fracture of the Björk-Shiley mitral valve].

Science.gov (United States)

Sugita, T; Yasuda, R; Watarida, S; Onoe, M; Tabata, R; Mori, A

1990-06-01

In May, 1982, a 49-year-old man underwent mitral valve replacement (MVR) in our hospital with a 31 mm Björk-Shiley prosthesis for mitral regurgitation. He had been doing well until his episode of palpitation and dyspnea of sudden onset, and was transferred to our ICU with severe cardiogenic shock in Aug, 1986. Chest X-ray film revealed pulmonary edema and breakage of the valve with migration of the disc and the minor strut of the prosthesis. He was operated upon 5 hours after the onset of his complaints. The minor strut was removed from the left upper pulmonary vein and mitral valve re-replacement was done with a 29 mm Björk-Shiley Monostrut valve. The disc which had dislocated into the abdominal aorta was also recovered on the twenty-third post operative day. His postoperative course was uneventful. Immediate diagnosis and subsequent re-operation is absolute indication for rescue from acute cardiac failure due to mechanical failure of any prosthetic valve.

MECHANICAL HEART-VALVE PROSTHESES - SOUND LEVEL AND RELATED COMPLAINTS

NARCIS (Netherlands)

LAURENS, RRP; WIT, HP; EBELS, T

In a randomised study, we investigated the sound production of mechanical heart valve prostheses and the complaints related to this sound. The CarboMedics, Bjork-Shiley monostrut and StJude Medical prostheses were compared. A-weighted levels of the pulse-like sound produced by the prosthesis were

Complete Transversal Disc Fracture in a Björk-Shiley Delrin Mitral Valve Prosthesis 43 Years After Implantation.

Science.gov (United States)

González-Santos, Jose María; Arnáiz-García, María Elena; Dalmau-Sorlí, María José; Sastre-Rincón, Jose Alfonso; Hernández-Hernández, Jesús; Pérez-Losada, María Elena; Sagredo-Meneses, Víctor; López-Rodríguez, Javier

2016-10-01

A patient who underwent previous implantation of a mitral valve replacement with a Björk-Shiley Delrin (BSD) mitral valve prosthesis during infancy was admitted to our institution 43 years later after an episode of syncope and cardiac arrest. Under extreme hemodynamic instability, a mitral valve prosthetic dysfunction causing massive mitral regurgitation was identified. The patient underwent an emergent cardiac operation, and a complete disc fracture with partial disc migration was found. Exceptional cases of mechanical prosthetic heart valve fracture exist. We report the first case of complete transversal disc rupture of a BSD mitral valve prosthesis after the longest period of implantation ever reported in that position. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Isolated mitral valve replacement with the Kay-Shiley disc. valve. Acturial analysis of the long term results.

Science.gov (United States)

Wellons, H A; Strauch, R S; Nolan, S P; Muller, W H

1975-11-01

During a five-year period the Kay-Shiley (K and T series) prosthesis was used for 83 isolated mitral valve replacements. There were 14 early deaths, for a 17.28 per cent mortality rate. Survival determined by the actuarial method revealed a 6 year cumulative survival rate of 39.8 per cent. Thromboembolism was a significant problem in this series, with 33 patients experiencing a total of 55 embolic events. This represented a rate of 24.7 emboli per 1,000 patient months at risk. From our experience, it is concluded that the Kay-Shiley prosthesis is associated with a high incidence of thromboembolism and late death.

Björk-Shiley convexoconcave valves: susceptibility artifacts at brain MR imaging and mechanical valve fractures.

Science.gov (United States)

van Gorp, Maarten J; van der Graaf, Yolanda; de Mol, Bas A J M; Bakker, Chris J G; Witkamp, Theo D; Ramos, Lino M P; Mali, Willem P T M

2004-03-01

To assess the relationship between heart valve history and susceptibility artifacts at magnetic resonance (MR) imaging of the brain in patients with Björk-Shiley convexoconcave (BSCC) valves. MR images of the brain were obtained in 58 patients with prosthetic heart valves: 20 patients had BSCC valve replacements, and 38 had other types of heart valves. Two experienced neuroradiologists determined the presence or absence of susceptibility artifacts in a consensus reading. Artifacts were defined as characteristic black spots that were visible on T2*-weighted gradient-echo MR images. The statuses of the 20 explanted BSCC valves-specifically, whether they were intact or had an outlet strut fracture (OSF) or a single-leg fracture (SLF)-had been determined earlier. Number of artifacts seen at brain MR imaging was correlated with explanted valve status, and differences were analyzed with nonparametric statistical tests. Significantly more patients with BSCC valves (17 [85%] of 20 patients) than patients with other types of prosthetic valves (18 [47%] of 38 patients) had susceptibility artifacts at MR imaging (P =.005). BSCC valve OSFs were associated with a significantly higher number of artifacts than were intact BSCC valves (P =.01). No significant relationship between SLF and number of artifacts was observed. Susceptibility artifacts at brain MR imaging are not restricted to patients with BSCC valves. These artifacts can be seen on images obtained in patients with various other types of fractured and intact prosthetic heart valves. Copyright RSNA, 2004

Quantitative assessment of the presence of a single leg separation in Björk-Shiley convexoconcave prosthetic heart valves.

Science.gov (United States)

Vrooman, H A; Maliepaard, C; van der Linden, L P; Jessurun, E R; Ludwig, J W; Plokker, H W; Schalij, M J; Weeda, H W; Laufer, J L; Huysmans, H A; Reiber, J H

1997-09-01

The authors developed an analytic software package for the objective and reproducible assessment of a single leg separation (SLS) in the outlet strut of Björk-Shiley convexoconcave (BSCC) prosthetic heart valves. The radiographic cinefilm recordings of 18 phantom valves (12 intact and 6 SLS) and of 43 patient valves were acquired. After digitization of regions of interest in a cineframe, several processing steps were carried out to obtain a one-dimensional corrected and averaged density profile along the central axis of each strut leg. To characterize the degree of possible separation, two quantitative measures were introduced: the normalized pit depth (NPD) and the depth-sigma ratio (DSR). The group of 43 patient studies was divided into a learning set (25 patients) and a test set (18 patients). All phantom valves with an SLS were detected (sensitivity, 100%) at a specificity of 100%. The threshold values for the NPD and the DSR to decide whether a fracture was present or not were 3.6 and 2.5, respectively. On the basis of the visual interpretations of the 25 patient studies (learning set) by an expert panel, it was concluded that none of the patients had an SLS. To achieve a 100% specificity by quantitative analysis, the threshold values for the NPD and the DSR were set at 5.8 and 2.5, respectively, for the patient data. Based on these threshold values, the analysis of patient data from the test set resulted in one false-negative detection and three false-positive detections. An analytic software package for the detection of an SLS was developed. Phantom data showed excellent sensitivity (100%) and specificity (100%). Further research and software development is needed to increase the sensitivity and specificity for patient data.

Cylindrical concave body of composite fibrous material

International Nuclear Information System (INIS)

1979-01-01

The invention is concerned with a cylindrical concave body of compound fibrous material which is intended to be exposed to high rotation speeds around its own longitudinal axis. The concave body in question has at least one layer of fibrils that are interwoven and enclose an identical angle with the longitudinal axis of the concave body in both directions. The concave body in question also has at least a second layer of fibrils that run in the direction of the circumference and are fitted radially to the outside. The cylindrical concave body of the invention is particularly well suited for application as a rotor tube in a gas ultra-centrifuge

Log-concavity property for some well-known distributions

Directory of Open Access Journals (Sweden)

G. R. Mohtashami Borzadaran

2011-12-01

Full Text Available Interesting properties and propositions, in many branches of science such as economics have been obtained according to the property of cumulative distribution function of a random variable as a concave function. Caplin and Nalebuff (1988,1989, Bagnoli and Khanna (1989 and Bagnoli and Bergstrom (1989 , 1989, 2005 have discussed the log-concavity property of probability distributions and their applications, especially in economics. Log-concavity concerns twice differentiable real-valued function g whose domain is an interval on extended real line. g as a function is said to be log-concave on the interval (a,b if the function ln(g is a concave function on (a,b. Log-concavity of g on (a,b is equivalent to g'/g being monotone decreasing on (a,b or (ln(g" 6] have obtained log-concavity for distributions such as normal, logistic, extreme-value, exponential, Laplace, Weibull, power function, uniform, gamma, beta, Pareto, log-normal, Student's t, Cauchy and F distributions. We have discussed and introduced the continuous versions of the Pearson family, also found the log-concavity for this family in general cases, and then obtained the log-concavity property for each distribution that is a member of Pearson family. For the Burr family these cases have been calculated, even for each distribution that belongs to Burr family. Also, log-concavity results for distributions such as generalized gamma distributions, Feller-Pareto distributions, generalized Inverse Gaussian distributions and generalized Log-normal distributions have been obtained.

ON THE GENERALIZED CONVEXITY AND CONCAVITY

Directory of Open Access Journals (Sweden)

Bhayo B.

2015-11-01

Full Text Available A function ƒ : R+ → R+ is (m1, m2-convex (concave if ƒ(m1(x,y ≤ (≥ m2(ƒ(x, ƒ(y for all x,y Є R+ = (0,∞ and m1 and m2 are two mean functions. Anderson et al. [1] studies the dependence of (m1, m2-convexity (concavity on m1 and m2 and gave the sufficient conditions of (m1, m2-convexity and concavity of a function defined by Maclaurin series. In this paper, we make a contribution to the topic and study the (m1, m2-convexity and concavity of a function where m1 and m2 are identric mean, Alzer mean mean. As well, we prove a conjecture posed by Bruce Ebanks in [2].

Björk-Shiley strut fracture and disc escape: literature review and a method of disc retrieval.

Science.gov (United States)

Hendel, P N

1989-03-01

Embolization of a prosthetic valve poppet is a rare but life-threatening event. It was reported sporadically before the introduction of the Björk-Shiley 70-degree convexoconcave prosthesis in 1980. Since that time, there have been a large number of reported mechanical failures with disc escape. The rate for the 29-mm to 33-mm mitral valves is estimated as 5.2%. In 29 of 35 patients (including the 2 presented here) in whom the site of disc lodgment could be determined, the disc was in the descending or abdominal aorta. Fifteen of these patients died. Six survivors had the disc removed at the same operation and 6 at a later operation. In 2 patients, the disc was not removed. In 2 patients in whom the disc was not removed initially, it was thought to contribute to postoperative complications. Two more cases of structural failure of the Björk-Shiley convexoconcave prosthesis are presented. A transpericardial approach to the descending aorta on bypass is described. It allows easy removal of the disc and eliminates the need for a second operation.

Alpha-Concave Hull, a Generalization of Convex Hull

OpenAIRE

Asaeedi, Saeed; Didehvar, Farzad; Mohades, Ali

2013-01-01

Bounding hull, such as convex hull, concave hull, alpha shapes etc. has vast applications in different areas especially in computational geometry. Alpha shape and concave hull are generalizations of convex hull. Unlike the convex hull, they construct non-convex enclosure on a set of points. In this paper, we introduce another generalization of convex hull, named alpha-concave hull, and compare this concept with convex hull and alpha shape. We show that the alpha-concave hull is also a general...

Neural Network to Solve Concave Games

OpenAIRE

Liu, Zixin; Wang, Nengfa

2014-01-01

The issue on neural network method to solve concave games is concerned. Combined with variational inequality, Ky Fan inequality, and projection equation, concave games are transformed into a neural network model. On the basis of the Lyapunov stable theory, some stability results are also given. Finally, two classic games’ simulation results are given to illustrate the theoretical results.

Log-concave Probability Distributions: Theory and Statistical Testing

DEFF Research Database (Denmark)

An, Mark Yuing

1996-01-01

This paper studies the broad class of log-concave probability distributions that arise in economics of uncertainty and information. For univariate, continuous, and log-concave random variables we prove useful properties without imposing the differentiability of density functions. Discrete...... and multivariate distributions are also discussed. We propose simple non-parametric testing procedures for log-concavity. The test statistics are constructed to test one of the two implicati ons of log-concavity: increasing hazard rates and new-is-better-than-used (NBU) property. The test for increasing hazard...... rates are based on normalized spacing of the sample order statistics. The tests for NBU property fall into the category of Hoeffding's U-statistics...

[Lessons from a heart valve prosthesis controversy].

Science.gov (United States)

Vandenbroucke, J P; Grobbee, D E

1998-07-18

Two lessons are to be learnt from the Björk-Shiley heart valve prosthesis tragedy. In the first place pharmacoepidemiologic studies are seriously hampered by recent privacy legislation. Individual patients carrying such a prosthesis cannot be traced and advised as to their health risks any more, because their legal autonomy has to be respected. This is clearly not to their advantage. In the second place the atmosphere of marketing and litigation and the increasing dependency of researchers on money from sources with conflicting interests is not conducive to a well-informed and balanced judgement of the epidemiological evidence of safety and efficacy of medical treatments.

Concave microwell plate facilitates chondrogenesis from mesenchymal stem cells.

Science.gov (United States)

Ko, Ji-Yun; Im, Gun-Il

2016-11-01

To compare in vitro chondrogenesis from bone marrow-derived mesenchymal stem cells using concave microwell plates with those obtained using culture tubes. Pellets cultured in concave microwell plates had a significantly higher level of GAG per DNA content and greater proteoglycan content than those cultured in tubes at day 7 and 14. Three chondrogenic markers, SOX-9, COL2A1 and aggrecan, showed significantly higher expression in pellets cultured in concave microwell plates than those cultured in tubes at day 7 and 14. At day 21, there was not a significant difference in the expression of these markers. COL10A1, the typical hypertrophy marker, was significantly lower in concave microwell plates during the whole culture period. Runx-2, a marker of hypertrophy and osteogenesis, was significantly lower at day 7 in pellets cultured in concave microwell plates than those cultured in tubes. Concave microwell plates provide a convenient and effective tool for the study of in vitro chondrogenesis and may replace the use of propylene culture tube.

Generalized concavity in fuzzy optimization and decision analysis

CERN Document Server

Ramík, Jaroslav

2002-01-01

Convexity of sets in linear spaces, and concavity and convexity of functions, lie at the root of beautiful theoretical results that are at the same time extremely useful in the analysis and solution of optimization problems, including problems of either single objective or multiple objectives. Not all of these results rely necessarily on convexity and concavity; some of the results can guarantee that each local optimum is also a global optimum, giving these methods broader application to a wider class of problems. Hence, the focus of the first part of the book is concerned with several types of generalized convex sets and generalized concave functions. In addition to their applicability to nonconvex optimization, these convex sets and generalized concave functions are used in the book's second part, where decision-making and optimization problems under uncertainty are investigated. Uncertainty in the problem data often cannot be avoided when dealing with practical problems. Errors occur in real-world data for...

Experimental analysis of an MIM capacitor with a concave shield

International Nuclear Information System (INIS)

Liu Lintao; Yu Mingyan; Wang Jinxiang

2009-01-01

A novel shielding scheme is developed by inserting a concave shield between a metal-insulator-metal (MIM) capacitor and the silicon substrate. Chip measurements reveal that the concave shield improves the quality factor by 11% at 11.8 GHz and 14% at 18.8 GHz compared with an unshielded MIM capacitor. It also alleviates the effect on shunt capacitance between the bottom plate of the MIM capacitor and the shield layer. Moreover, because the concave shields simplify substrate modeling, a simple circuit model of the MIM capacitor with concave shield is presented for radio frequency applications.

Bimacrocyclic concave N-heterocyclic carbenes (NHCs): synthesis, structure, and application in catalyses

OpenAIRE

Lüning , Ulrich; Winkelmann , Ole

2009-01-01

Abstract Imidazolinium moieties have been incorporated into bimacrocycles to generate precursors for concave N-heterocyclic carbenes (NHCs). Starting from 2-nitroresorcinol and alkenols, symmetric concave imidazolinium salts 1 were obtained. Bimacrocyclization was achieved via ring closing metathesis (RCM). In an analogous fashion, axially chiral concave imidazolinium salts 2 were obtained by using a naphthalene bridgehead devoid of local C2-symmetry. The concave NHCs derived from ...

Disc dislodgment in Björk Shiley mitral valve prosthesis: two successfully operated cases.

Science.gov (United States)

Dubernet, J; Irarrázaval, M J; Urzúa, J; Maturana, G; Morán, S; Lema, G; Asenjo, F; Fajuri, A

1986-02-01

Two 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.

Concavity Theorems for Energy Surfaces

OpenAIRE

Giraud, B. G.; Karataglidis, S.

2011-01-01

Concavity properties prevent the existence of significant landscapes in energy surfaces obtained by strict constrained energy minimizations. The inherent contradiction is due to fluctuations of collective coordinates. A solution to those fluctuations is given.

New high-precision deep concave optical surface manufacturing capability

Science.gov (United States)

Piché, François; Maloney, Chris; VanKerkhove, Steve; Supranowicz, Chris; Dumas, Paul; Donohue, Keith

2017-10-01

This paper describes the manufacturing steps necessary to manufacture hemispherical concave aspheric mirrors for high- NA systems. The process chain is considered from generation to final figuring and includes metrology testing during the various manufacturing steps. Corning Incorporated has developed this process by taking advantage of recent advances in commercially available Satisloh and QED Technologies equipment. Results are presented on a 100 mm concave radius nearly hemispherical (NA = 0.94) fused silica sphere with a better than 5 nm RMS figure. Part interferometric metrology was obtained on a QED stitching interferometer. Final figure was made possible by the implementation of a high-NA rotational MRF mode recently developed by QED Technologies which is used at Corning Incorporated for production. We also present results from a 75 mm concave radius (NA = 0.88) Corning ULE sphere that was produced using sub-aperture tools from generation to final figuring. This part demonstrates the production chain from blank to finished optics for high-NA concave asphere.

Enhanced Absorption in Organic Thin-Films from Imprinted Concave Nanostructures

DEFF Research Database (Denmark)

Goszczak, Arkadiusz Jaroslaw; Rubahn, Horst-Günter; Madsen, Morten

2017-01-01

In this work, a rapid, replicable method for imprinting concave nanostructures to be used as functional light-trapping nanostructures in organic thin-films is presented. Porous anodic alumina templates were fabricated both by anodization of thick Al foils and by anodization of submicrometer thin Al...... patterns and used for imprinting of spin coated photoresist on glass substrates. We have investigated semi-periodic and aperiodic imprinted large concave patterns fabricated from rigid masters after anodization of Al in H3PO4. We show that metal covered imprinted concaves show enhancement in absorption...

Convexity and concavity constants in Lorentz and Marcinkiewicz spaces

Science.gov (United States)

Kaminska, Anna; Parrish, Anca M.

2008-07-01

We provide here the formulas for the q-convexity and q-concavity constants for function and sequence Lorentz spaces associated to either decreasing or increasing weights. It yields also the formula for the q-convexity constants in function and sequence Marcinkiewicz spaces. In this paper we extent and enhance the results from [G.J.O. Jameson, The q-concavity constants of Lorentz sequence spaces and related inequalities, Math. Z. 227 (1998) 129-142] and [A. Kaminska, A.M. Parrish, The q-concavity and q-convexity constants in Lorentz spaces, in: Banach Spaces and Their Applications in Analysis, Conference in Honor of Nigel Kalton, May 2006, Walter de Gruyter, Berlin, 2007, pp. 357-373].

Hydrogen adsorption-mediated synthesis of concave Pt nanocubes and their enhanced electrocatalytic activity

Science.gov (United States)

Lu, Bang-An; Du, Jia-Huan; Sheng, Tian; Tian, Na; Xiao, Jing; Liu, Li; Xu, Bin-Bin; Zhou, Zhi-You; Sun, Shi-Gang

2016-06-01

Concave nanocubes are enclosed by high-index facets and have negative curvature; they are expected to have enhanced reactivity, as compared to nanocubes with flat surfaces. Herein, we propose and demonstrate a new strategy for the synthesis of concave Pt nanocubes with {hk0} high-index facets, by using a hydrogen adsorption-mediated electrochemical square-wave potential method. It was found that Pt atoms prefer to deposit on edge sites rather than terrace sites on Pt surfaces with intensive hydrogen adsorption, resulting in the formation of concave structures. The as-prepared concave Pt nanocubes exhibit enhanced catalytic activity and stability towards oxidation of ethanol and formic acid in acidic solutions, compared to commercial Pt/C catalysts.Concave nanocubes are enclosed by high-index facets and have negative curvature; they are expected to have enhanced reactivity, as compared to nanocubes with flat surfaces. Herein, we propose and demonstrate a new strategy for the synthesis of concave Pt nanocubes with {hk0} high-index facets, by using a hydrogen adsorption-mediated electrochemical square-wave potential method. It was found that Pt atoms prefer to deposit on edge sites rather than terrace sites on Pt surfaces with intensive hydrogen adsorption, resulting in the formation of concave structures. The as-prepared concave Pt nanocubes exhibit enhanced catalytic activity and stability towards oxidation of ethanol and formic acid in acidic solutions, compared to commercial Pt/C catalysts. Electronic supplementary information (ESI) available: Details of DFT calculation, SEM images of concave Pt nanocubes, mass activity and stability characterization of the catalysts. See DOI: 10.1039/c6nr02349e

Enhanced Absorption in Organic Thin-Films from Imprinted Concave Nanostructures

Directory of Open Access Journals (Sweden)

Arkadiusz Jarosław GOSZCZAK

2017-02-01

Full Text Available In this work, a rapid, replicable method for imprinting concave nanostructures to be used as functional light-trapping nanostructures in organic thin-films is presented. Porous anodic alumina templates were fabricated both by anodization of thick Al foils and by anodization of submicrometer thin Al films evaporated via e-beam evaporation on Si substrates. The template formation leads to natural patterning of the underlying Al layers that are used as rigid masters for stamp fabrication, after selective etching of the porous anodic alumina. PDMS stamps were made after replicating the Al concave patterns and used for imprinting of spin coated photoresist on glass substrates. We have investigated semi-periodic and aperiodic imprinted large concave patterns fabricated from rigid masters after anodization of Al in H3PO4. We show that metal covered imprinted concaves show enhancement in absorption that is attributed to field enhancement and diffuse scattering, leading to efficient light trapping for a selected active layer material (P3HT:PCBM.DOI: http://dx.doi.org/10.5755/j01.ms.23.1.14188

Fast approximate convex decomposition using relative concavity

KAUST Repository

Ghosh, Mukulika; Amato, Nancy M.; Lu, Yanyan; Lien, Jyh-Ming

2013-01-01

Approximate convex decomposition (ACD) is a technique that partitions an input object into approximately convex components. Decomposition into approximately convex pieces is both more efficient to compute than exact convex decomposition and can also generate a more manageable number of components. It can be used as a basis of divide-and-conquer algorithms for applications such as collision detection, skeleton extraction and mesh generation. In this paper, we propose a new method called Fast Approximate Convex Decomposition (FACD) that improves the quality of the decomposition and reduces the cost of computing it for both 2D and 3D models. In particular, we propose a new strategy for evaluating potential cuts that aims to reduce the relative concavity, rather than absolute concavity. As shown in our results, this leads to more natural and smaller decompositions that include components for small but important features such as toes or fingers while not decomposing larger components, such as the torso, that may have concavities due to surface texture. Second, instead of decomposing a component into two pieces at each step, as in the original ACD, we propose a new strategy that uses a dynamic programming approach to select a set of n c non-crossing (independent) cuts that can be simultaneously applied to decompose the component into n c+1 components. This reduces the depth of recursion and, together with a more efficient method for computing the concavity measure, leads to significant gains in efficiency. We provide comparative results for 2D and 3D models illustrating the improvements obtained by FACD over ACD and we compare with the segmentation methods in the Princeton Shape Benchmark by Chen et al. (2009) [31]. © 2012 Elsevier Ltd. All rights reserved.

Fast approximate convex decomposition using relative concavity

KAUST Repository

Ghosh, Mukulika

2013-02-01

Approximate convex decomposition (ACD) is a technique that partitions an input object into approximately convex components. Decomposition into approximately convex pieces is both more efficient to compute than exact convex decomposition and can also generate a more manageable number of components. It can be used as a basis of divide-and-conquer algorithms for applications such as collision detection, skeleton extraction and mesh generation. In this paper, we propose a new method called Fast Approximate Convex Decomposition (FACD) that improves the quality of the decomposition and reduces the cost of computing it for both 2D and 3D models. In particular, we propose a new strategy for evaluating potential cuts that aims to reduce the relative concavity, rather than absolute concavity. As shown in our results, this leads to more natural and smaller decompositions that include components for small but important features such as toes or fingers while not decomposing larger components, such as the torso, that may have concavities due to surface texture. Second, instead of decomposing a component into two pieces at each step, as in the original ACD, we propose a new strategy that uses a dynamic programming approach to select a set of n c non-crossing (independent) cuts that can be simultaneously applied to decompose the component into n c+1 components. This reduces the depth of recursion and, together with a more efficient method for computing the concavity measure, leads to significant gains in efficiency. We provide comparative results for 2D and 3D models illustrating the improvements obtained by FACD over ACD and we compare with the segmentation methods in the Princeton Shape Benchmark by Chen et al. (2009) [31]. © 2012 Elsevier Ltd. All rights reserved.

Concave distal end of ulna metaphysis alone is not a sign of rickets

Energy Technology Data Exchange (ETDEWEB)

Oestreich, Alan E. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, 5031, Cincinnati, OH (United States)

2015-07-15

Statements have been made in the literature and in legal testimony that misrepresent the radiographic finding of concave distal end of the ulnar metaphysis. To demonstrate that a concave distal end of the ossified ulna in infancy can be normal. Eighty distal wrists of randomly selected infants in the first year of life with radiographic evidence that ruled out rickets were reviewed. In 16 of the cases (20%), mild or moderate concavity of the distal end of the ulna was seen. An intact metaphyseal collar of distal radius or ulna confirmed the absence of radiographic rickets. The finding of 20% of concave distal ulnas in the first year of life confirms the widely acknowledged statements that concave distal end of the ulna alone is not indicative of rickets. Statements to the contrary are not justified. (orig.)

Concave distal end of ulna metaphysis alone is not a sign of rickets

International Nuclear Information System (INIS)

Oestreich, Alan E.

2015-01-01

Statements have been made in the literature and in legal testimony that misrepresent the radiographic finding of concave distal end of the ulnar metaphysis. To demonstrate that a concave distal end of the ossified ulna in infancy can be normal. Eighty distal wrists of randomly selected infants in the first year of life with radiographic evidence that ruled out rickets were reviewed. In 16 of the cases (20%), mild or moderate concavity of the distal end of the ulna was seen. An intact metaphyseal collar of distal radius or ulna confirmed the absence of radiographic rickets. The finding of 20% of concave distal ulnas in the first year of life confirms the widely acknowledged statements that concave distal end of the ulna alone is not indicative of rickets. Statements to the contrary are not justified. (orig.)

Field arrangement and dosimetry verification for concave target

International Nuclear Information System (INIS)

Chen Liang; Wang Huankun; Li Yumin

2005-01-01

Objective: To provide a method of radiotherapy field arrangement for concave paraspinal target. Methods: Plan was designed for concave target in wax phantom and the selected patients by the guidance of beam eye view (BEV) provided by a 3D treatment planning system (CREAT EXPERT). In BEV, the inner border of all tangential fields was 2 mm out of the organ at risk (OAR) and the outer border was 5 mm beyond the target. Dosimetry films and ion chamber were used to verify the dose distribution and point dose in the wax phantom. Results: Dose distribution in phantom and patient was homogeneous. The mean dose of OAR in phantom did not exceed 16% of the prescribed dose. Isodose curves dropped more than 8% per mm between the target and OAR in the phantom. Film dosimetry coincided well with the calculated results. Position error in high dose region was with- in 4 mm and absolute dose errors were no more than 5%. Conclusion: Tangential field arrangement is valuable and practical in radiotherapy for concave paraspinal targets. (authors)

High voltage photo-switch package module having encapsulation with profiled metallized concavities

Science.gov (United States)

Sullivan, James S; Sanders, David M; Hawkins, Steven A; Sampayan, Stephen A

2015-05-05

A photo-conductive switch package module having a photo-conductive substrate or wafer with opposing electrode-interface surfaces metalized with first metallic layers formed thereon, and encapsulated with a dielectric encapsulation material such as for example epoxy. The first metallic layers are exposed through the encapsulation via encapsulation concavities which have a known contour profile, such as a Rogowski edge profile. Second metallic layers are then formed to line the concavities and come in contact with the first metal layer, to form profiled and metalized encapsulation concavities which mitigate enhancement points at the edges of electrodes matingly seated in the concavities. One or more optical waveguides may also be bonded to the substrate for coupling light into the photo-conductive wafer, with the encapsulation also encapsulating the waveguides.

STRONG ORACLE OPTIMALITY OF FOLDED CONCAVE PENALIZED ESTIMATION.

Science.gov (United States)

Fan, Jianqing; Xue, Lingzhou; Zou, Hui

2014-06-01

Folded concave penalization methods have been shown to enjoy the strong oracle property for high-dimensional sparse estimation. However, a folded concave penalization problem usually has multiple local solutions and the oracle property is established only for one of the unknown local solutions. A challenging fundamental issue still remains that it is not clear whether the local optimum computed by a given optimization algorithm possesses those nice theoretical properties. To close this important theoretical gap in over a decade, we provide a unified theory to show explicitly how to obtain the oracle solution via the local linear approximation algorithm. For a folded concave penalized estimation problem, we show that as long as the problem is localizable and the oracle estimator is well behaved, we can obtain the oracle estimator by using the one-step local linear approximation. In addition, once the oracle estimator is obtained, the local linear approximation algorithm converges, namely it produces the same estimator in the next iteration. The general theory is demonstrated by using four classical sparse estimation problems, i.e., sparse linear regression, sparse logistic regression, sparse precision matrix estimation and sparse quantile regression.

On the impact of a concave nosed axisymmetric body on a free surface

Science.gov (United States)

Mathai, Varghese; Govardhan, Raghuraman N.; Arakeri, Vijay H.

2015-02-01

We report on an experimental study of the vertical impact of a concave nosed axisymmetric body on a free surface. Previous studies have shown that bodies with a convex nose, like a sphere, produce a well defined splash with a relatively large cavity behind the model. In contrast, we find that with a concave nose, there is hardly a splash and the cavity extent is greatly reduced. This may be explained by the fact that in the concave nosed case, the initial impact is between a confined air pocket and the free surface unlike in the convex nosed case. From measurements of the unsteady pressure in the concave nose portion, we show that in this case, the maximum pressures are significantly lower than the classically expected "water hammer" pressures and also lower than those generally measured on other geometries. Thus, the presence of an air pocket in the case of a concave nosed body adds an interesting dimension to the classical problem of impact of solid bodies on to a free surface.

Novel high-NA MRF toolpath supports production of concave hemispheres

Science.gov (United States)

Maloney, Chris; Supranowitz, Chris; Dumas, Paul

2017-10-01

Many optical system designs rely on high numerical aperture (NA) optics, including lithography and defense systems. Lithography systems require high-NA optics to image the fine patterns from a photomask, and many defense systems require the use of domes. The methods for manufacturing such optics with large half angles have often been treated as proprietary by most manufacturers due to the challenges involved. In the past, many high-NA concave surfaces could not be polished by magnetorheological finishing (MRF) due to collisions with the hardware underneath the polishing head. By leveraging concepts that were developed to enable freeform raster MRF capabilities, QED Technologies has implemented a novel toolpath to facilitate a new high-NA rotational MRF mode. This concept involves the use of the B-axis (rotational axis) in combination with a "virtual-axis" that utilizes the geometry of the polishing head. Hardware collisions that previously restricted the concave half angle limit can now be avoided and the new functionality has been seamlessly integrated into the software. This new MRF mode overcomes past limitations for polishing concave surfaces to now accommodate full concave hemispheres as well as extend the capabilities for full convex hemispheres. We discuss some of the previous limitations, and demonstrate the extended capabilities using this novel toolpath. Polishing results are used to qualify the new toolpath to ensure similar results to the "standard" rotational MRF mode.

Controlled synthesis of concave tetrahedral palladium nanocrystals by reducing Pd(acac)2 with carbon monoxide

International Nuclear Information System (INIS)

Zhu, Hai; Chi, Quan; Zhao, Yanxi; Li, Chunya; Tang, Heqing; Li, Jinlin; Huang, Tao; Liu, Hanfan

2012-01-01

Graphical abstract: By using CO as a reducing agent, uniform and well-defined concave tetrahedral Pd nanocrystals were successfully synthesized. CO flow rate was the most essential for the formation of the concave tetrahedral nanostructures. The morphologies and sizes of the final products can be well controlled by adjusting the flow rate of CO. Highlights: ► By using CO as a reducing agent, concave tetrahedral Pd nanocrystals were obtained. ► CO flow rate is critical to the formation of concave tetrahedral Pd nanocrystals. ► The selective adsorption of CO on (1 1 0) facets is essential to concave Pd tetrahedra. -- Abstract: CO reducing strategy to control the morphologies of palladium nanocrystals was investigated. By using CO as a reducing agent, uniform and well-defined concave tetrahedral Pd nanocrystals with a mean size of about 55 ± 2 nm were readily synthesized with Pd(acac) 2 as a precursor and PVP as a stabilizer. The structures of the as-prepared Pd nanocrystals were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), ultraviolet–visible (UV–vis) absorption spectroscopy and electrochemical measurements. The results demonstrated that CO was the most essential for the formation of the concave tetrahedral Pd nanostructures. The morphologies and sizes of the final products can be well controlled by adjusting the flow rate of CO. The most appropriate CO flow rate, temperature and time for the formation of the ideal concave tetrahedral Pd nanocrystals was 0.033 mL s −1 , 100 °C and 3 h, respectively.

On the impact of a concave nosed axisymmetric body on a free surface

OpenAIRE

Mathai, Varghese; Govardhan, Raghuraman N.; Arakeri, Vijay H.

2017-01-01

We report on an experimental study of the vertical impact of a concave nosed axisymmetric body on a free surface. Previous studies have shown that bodies with a convex nose, like a sphere, produce a well defined splash with a relatively large cavity behind the model. In contrast, we find that with a concave nose, there is hardly a splash and the cavity extent is greatly reduced. This may be explained by the fact that in the concave nosed case, the initial impact is between a confined air pock...

Smith-Purcell radiation from concave dotted gratings

Science.gov (United States)

Sergeeva, D. Yu.; Tishchenko, A. A.; Aryshev, A. S.; Strikhanov, M. N.

2018-02-01

We present the first-principles theory of Smith-Purcell effect from the concave dotted grating consisting of bent chains of separated micro- or nanoparticles. The numerical analysis demonstrates that the obtained spectral-angular distributions change significantly depending on the structure of the grating.

Optimal Portfolio Selection Under Concave Price Impact

International Nuclear Information System (INIS)

Ma Jin; Song Qingshuo; Xu Jing; Zhang Jianfeng

2013-01-01

In this paper we study an optimal portfolio selection problem under instantaneous price impact. Based on some empirical analysis in the literature, we model such impact as a concave function of the trading size when the trading size is small. The price impact can be thought of as either a liquidity cost or a transaction cost, but the concavity nature of the cost leads to some fundamental difference from those in the existing literature. We show that the problem can be reduced to an impulse control problem, but without fixed cost, and that the value function is a viscosity solution to a special type of Quasi-Variational Inequality (QVI). We also prove directly (without using the solution to the QVI) that the optimal strategy exists and more importantly, despite the absence of a fixed cost, it is still in a “piecewise constant” form, reflecting a more practical perspective.

Optimal Portfolio Selection Under Concave Price Impact

Energy Technology Data Exchange (ETDEWEB)

Ma Jin, E-mail: jinma@usc.edu [University of Southern California, Department of Mathematics (United States); Song Qingshuo, E-mail: songe.qingshuo@cityu.edu.hk [City University of Hong Kong, Department of Mathematics (Hong Kong); Xu Jing, E-mail: xujing8023@yahoo.com.cn [Chongqing University, School of Economics and Business Administration (China); Zhang Jianfeng, E-mail: jianfenz@usc.edu [University of Southern California, Department of Mathematics (United States)

2013-06-15

In this paper we study an optimal portfolio selection problem under instantaneous price impact. Based on some empirical analysis in the literature, we model such impact as a concave function of the trading size when the trading size is small. The price impact can be thought of as either a liquidity cost or a transaction cost, but the concavity nature of the cost leads to some fundamental difference from those in the existing literature. We show that the problem can be reduced to an impulse control problem, but without fixed cost, and that the value function is a viscosity solution to a special type of Quasi-Variational Inequality (QVI). We also prove directly (without using the solution to the QVI) that the optimal strategy exists and more importantly, despite the absence of a fixed cost, it is still in a 'piecewise constant' form, reflecting a more practical perspective.

The concave iris in pigment dispersion syndrome.

Science.gov (United States)

Liu, Lance; Ong, Ee Lin; Crowston, Jonathan

2011-01-01

To visualize the changes of the iris contour in patients with pigment dispersion syndrome after blinking, accommodation, and pharmacologic miosis using anterior segment optical coherence tomography. Observational case series. A total of 33 eyes of 20 patients with pigment dispersion syndrome. Each eye was imaged along the horizontal 0- to 180-degree meridian using the Visante Anterior Segment Imaging System (Carl Zeiss Meditec, Dublin, CA). Scans were performed at baseline and after focusing on an internal fixation target for 5 minutes, forced blinking, accommodation, and pharmacologic miosis with pilocarpine 2%. Quantitative analysis of the changes in the iris configuration. After 5 minutes of continual fixation, the iris became planar with the mean ± standard deviation curvature decreasing from 214 ± 74 μm to 67 ± 76 μm (P pigment dispersion syndrome after forced blinking, but the iris concavity recovered to 227 ± 113 μm (P = 0.34) and 238 ± 119 μm (P = 0.19) with the -3.0 and -6.0 diopter lenses, respectively. Pilocarpine-induced miosis caused the iris to assume a planar configuration in all subjects. This study shows that the iris in pigment dispersion syndrome assumes a planar configuration when fixating and that the concavity of the iris surface is not restored by blinking. Accommodation restored the iris concavity, suggesting that the posterior curvature of the iris in pigment dispersion syndrome is induced and probably maintained, at least in part, by accommodation. Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Optimization of bridge cables with concave fillets

DEFF Research Database (Denmark)

Burlina, Celeste; Georgakis, Christos T.; Larsen, Søren V.

In this paper the aerodynamic performance of new cable surfaces with concave fillet are examined and compared to plain, dimpled and helically filleted surfaces. To this end, an extensive wind-tunnel campaign was undertaken. Preliminary flow visualizations tests and static tests were performed to ...

A versatile curve-fit model for linear to deeply concave rank abundance curves

NARCIS (Netherlands)

Neuteboom, J.H.; Struik, P.C.

2005-01-01

A new, flexible curve-fit model for linear to concave rank abundance curves was conceptualized and validated using observational data. The model links the geometric-series model and log-series model and can also fit deeply concave rank abundance curves. The model is based ¿ in an unconventional way

Concave pulse shaping of a circularly polarized laser pulse from non-uniform overdense plasmas

Energy Technology Data Exchange (ETDEWEB)

Hur, Min Sup [School of Natural Science, UNIST, BanYeon-Ri 100, Ulju-gun, Ulsan, 689-798 (Korea, Republic of); Kulagin, Victor V. [Sternberg Astronomical Institute, Moscow State University, Universitetsky prosp. 13, Moscow, 119992 (Russian Federation); Suk, Hyyong, E-mail: hysuk@gist.ac.kr [Department of Physics and Photon Science, GIST, 123 Cheomdan-gwangiro, Buk-gu, Gwangju, 500-712 (Korea, Republic of)

2015-03-20

Pulse shaping of circularly polarized laser pulses in nonuniform overdense plasmas are investigated numerically. Specifically we show by two-dimensional particle-in-cell simulations the generation of a concave pulse front of a circularly polarized, a few tens of petawatt laser pulse from a density-tapered, overdense plasma slab. The concept used for the transverse-directional shaping is the differential transmittance depending on the plasma density, and the laser intensity. For suitable selection of the slab parameters for the concave pulse shaping, we studied numerically the pulse transmittance, which can be used for further parameter design of the pulse shaping. The concavely shaped circularly polarized pulse is expected to add more freedom in controlling the ion-beam characteristics in the RPDA regime. - Highlights: • Laser pulse shaping for a concave front by non-uniform overdense plasma was studied. • Particle-in-cell (PIC) simulations were used for the investigation. • A laser pulse can be shaped by a density-tapered overdense plasma. • The concave and sharp pulse front are useful in many laser–plasma applications. • They are important for ion acceleration, especially in the radiation pressure dominant regime.

[Design of flat field holographic concave grating for near-infrared spectrophotometer].

Science.gov (United States)

Xiang, Xian-Yi; Wen, Zhi-Yu

2008-07-01

Near-infrared spectrum analysis can be used to determine the nature or test quantitatively some chemical compositions by detecting molecular double frequency and multiple frequency absorption. It has been used in agriculture, biology, petrifaction, foodstuff, medicament, spinning and other fields. Near-infrared spectrophotometer is the main apparatus for near-infrared spectrum analysis, and the grating is the most important part of the apparatus. Based on holographic concave grating theory and optic design software CODE V, a flat field holographic concave grating for near-infrared spectrophotometer was designed from primary structure, which relied on global optimization of the software. The contradiction between wide spectrum bound and limited spectrum extension was resolved, aberrations were reduced successfully, spectrum information was utilized fully, and the optic structure of spectrometer was highly efficient. Using CODE V software, complex high-order aberration equations need not be solved, the result can be evaluated quickly, flat field and resolving power can be kept in balance, and the work efficiency is also enhanced. A paradigm of flat field holographic concave grating is given, it works between 900 nm to 1 700 nm, the diameter of the concave grating is 25 mm, and F/ # is 1. 5. The design result was analyzed and evaluated. It was showed that if the slit source, whose width is 50 microm, is used to reconstruction, the theoretic resolution capacity is better than 6.3 nm.

Log-Concavity Properties of Minkowski Valuations

OpenAIRE

Berg, Astrid; Parapatits, Lukas; Schuster, Franz E.; Weberndorfer, Manuel

2014-01-01

New Orlicz Brunn-Minkowski inequalities are established for rigid motion compatible Minkowski valuations of arbitrary degree. These extend classical log-concavity properties of intrinsic volumes and generalize seminal results of Lutwak and others. Two different approaches which refine previously employed techniques are explored. It is shown that both lead to the same class of Minkowski valuations for which these inequalities hold. An appendix by Semyon Alesker contains the proof of a new clas...

Classroom Note: Concavity and the Second Law of Thermodynamics

Science.gov (United States)

Dunning-Davies, J.

2003-01-01

The importance of the mathematical notion of concavity in relation to thermodynamics is stressed and it is shown how it can be useful in increasing the enthusiasm of physics' students for their mathematics' courses.

Manipulating the kinetics of seeded growth for edge-selective metal deposition and the formation of concave au nanocrystals.

Science.gov (United States)

Laskar, Moitree; Zhong, Xiaolan; Li, Zhi-Yuan; Skrabalak, Sara E

2013-10-01

By manipulating the kinetics of seeded growth through judicious control of reaction conditions, edge-selective metal deposition can be achieved to synthesize new Au nanostructures with face-centered concavities, referred to herein as Au overgrown trisoctahedra. These nanostructures display higher sensitivity to changes in refractive index compared to both Au traditional trisoctahedra and the Au nanocube seeds from which they are grown. Often, concave nanostructures are achieved by selective etching processes or corner-selective overgrowth and adopt a stellated profile rather than a profile with face-centered concavities. The presented results illustrate another strategy toward concave nanostructures and can facilitate the synthesis of new concave nanostructures for applications in catalysis and chemical sensing. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Availability of cosmetic treatment using novel cosmetics-based material on patients with craniofacial concavity.

Science.gov (United States)

Koyama, Shigeto; Kanetaka, Hiroyasu; Sagehashi, Yoshinori; Sasaki, Keiichi; Sato, Naoko

2018-03-08

Patients treated with maxillofacial prosthetics often experience emotional problems because of the remaining facial skin concavity such as a surgical scar. In such cases, cosmetic treatment can potentially correct their skin tone imperfections and deformities. This study aimed to evaluate the clinical availability of novel cosmetics-based material for craniofacial small concavity by initiating a cosmetic treatment in a preliminary case. Eighteen patients with aesthetic problems such as craniofacial deformities, small defects, and concavities on their faces underwent cosmetic treatment that was performed by makeup practitioners. Data were collected from the patient's charts and a survey questionnaire. A visual analog scale was used to conduct a survey regarding the satisfaction levels of the patients following cosmetic treatment with a novel cosmetics-based material. The cosmetic treatment was performed for a concavity on the left midface of a 67-year-old woman with partial maxillectomy. The novel cosmetics-based material was manufactured from a semi-translucent oil base. The satisfaction level of the patient increased after undergoing the cosmetic treatment. Regarding clinical applications, the novel cosmetics-based material can help reduce their cosmetic disturbance and restore the small deformity. These results suggest that the cosmetic treatment with the novel cosmetics-based material can be used as a subsidiary method for facial prostheses or an independent new method for correcting patients' small craniofacial concavity and for reducing visible deformity. Copyright © 2018 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Local matching indicators for concave transport costs

OpenAIRE

Delon , Julie; Salomon , Julien; Sobolevskii , A.

2010-01-01

International audience; In this note, we introduce a class of indicators that enable to compute efficiently optimal transport plans associated to arbitrary distributions of $N$ demands and $N$ supplies in $\\mathbf{R}$ in the case where the cost function is concave. The computational cost of these indicators is small and independent of $N$. A hierarchical use of them enables to obtain an efficient algorithm.

Structural Health Monitoring of Tall Buildings with Numerical Integrator and Convex-Concave Hull Classification

Directory of Open Access Journals (Sweden)

Suresh Thenozhi

2012-01-01

Full Text Available An important objective of health monitoring systems for tall buildings is to diagnose the state of the building and to evaluate its possible damage. In this paper, we use our prototype to evaluate our data-mining approach for the fault monitoring. The offset cancellation and high-pass filtering techniques are combined effectively to solve common problems in numerical integration of acceleration signals in real-time applications. The integration accuracy is improved compared with other numerical integrators. Then we introduce a novel method for support vector machine (SVM classification, called convex-concave hull. We use the Jarvis march method to decide the concave (nonconvex hull for the inseparable points. Finally the vertices of the convex-concave hull are applied for SVM training.

Heat transfer and forces on concave surfaces in free molecule flow.

Science.gov (United States)

Fan, C.

1971-01-01

A Monte Carlo modeling technique is described for mathematically simulating free molecular flows over a concave spherical surface and a concave cylindrical surface of finite length. The half-angle of the surfaces may vary from 0 to 90 degrees, and the incident flow may have an arbitrary speed ratio and an arbitrary angle of attack. Partial diffuse reflection and imperfect energy accommodation for molecules colliding with the surfaces are also considered. Results of heat transfer, drag and lift coefficients are presented for a variety of flow conditions. The present Monte Carlo results are shown to be in very good agreement with certain available theoretical solutions.

Convex and Radially Concave Contoured Distributions

Directory of Open Access Journals (Sweden)

Wolf-Dieter Richter

2015-01-01

Full Text Available Integral representations of the locally defined star-generalized surface content measures on star spheres are derived for boundary spheres of balls being convex or radially concave with respect to a fan in Rn. As a result, the general geometric measure representation of star-shaped probability distributions and the general stochastic representation of the corresponding random vectors allow additional specific interpretations in the two mentioned cases. Applications to estimating and testing hypotheses on scaling parameters are presented, and two-dimensional sample clouds are simulated.

Pd@Au core-shell nanocrystals with concave cubic shapes: kinetically controlled synthesis and electrocatalytic properties.

Science.gov (United States)

Zhang, Ling; Niu, Wenxin; Zhao, Jianming; Zhu, Shuyun; Yuan, Yali; Hua, Lianzhe; Xu, Guobao

2013-01-01

A new type of concave cubic Pd@Au core-shell nanocrystals is synthesized through a kinetically controlled growth process. Pd nanocubes of 56 nm are used as the inner core, and CTAC and Br(-) are used as the capping agent and selective adsorbent, respectively. A suitable ratio of HAuCl4 and cubic Pd seeds and the presence of Br(-) anions are critical to the growth of the concave cubic Pd@Au core-shell nanocrystals. The fast deposition rate on the corners of the cubic Pd seeds promotes the overgrowth of the Au outer shell along the direction, leading to the formation of concave cubic nanostructures. The reduction process is monitored by the surface plasmon resonance spectra of the nanocrystals, and the extinction band became broader and red shifted as the nanocrystals became larger. The electrocatalytic properties of the concave cubic Pd@Au core-shell nanocrystals were investigated with the cathodic electrochemiluminescence reaction of luminol and H2O2. A possible electrocatalytic mechanism was proposed and analyzed.

Performance of solar still with a concave wick evaporation surface

International Nuclear Information System (INIS)

Kabeel, A.E.

2009-01-01

Surfaces used for evaporation and condensation phenomenon play important roles in the performance of basin type solar still. In the present study, a concave wick surface was used for evaporation, whereas four sides of a pyramid shaped still were used for condensation. Use of jute wick increased the amount of absorbed solar radiation and enhanced the evaporation surface area. A concave shaped wick surface increases the evaporation area due to the capillary effect. Results show that average distillate productivity in day time was 4.1 l/m 2 and a maximum instantaneous system efficiency of 45% and average daily efficiency of 30% were recorded. The maximum hourly yield was 0.5 l/h. m 2 after solar noon. An estimated cost of 1 l of distillate was 0.065 $ for the presented solar still.

Performance of solar still with a concave wick evaporation surface

Energy Technology Data Exchange (ETDEWEB)

Kabeel, A.E. [Mechanical Power Department, Faculty of Engineering, Tanta University (Egypt)

2009-10-15

Surfaces used for evaporation and condensation phenomenon play important roles in the performance of basin type solar still. In the present study, a concave wick surface was used for evaporation, whereas four sides of a pyramid shaped still were used for condensation. Use of jute wick increased the amount of absorbed solar radiation and enhanced the evaporation surface area. A concave shaped wick surface increases the evaporation area due to the capillary effect. Results show that average distillate productivity in day time was 4.1 l/m{sup 2} and a maximum instantaneous system efficiency of 45% and average daily efficiency of 30% were recorded. The maximum hourly yield was 0.5 l/h. m{sup 2} after solar noon. An estimated cost of 1l of distillate was 0.065 $ for the presented solar still. (author)

Sharing a common resource with concave benefits

OpenAIRE

Ambec, S.

2006-01-01

A group of agents enjoy concave and single-peak benefit functions from consuming a shared resource. They also value money (transfers). The resource is scarce in the sense that not everybody can consume its peak. The paper characterizes the unique (resource and money) allocation that is efficient, incentive compatible and equal-sharing individual rational. It can be implemented (i) by selling the resource or taxing extraction and redistributing the money collected equally, or (ii) by assigning...

Directable weathering of concave rock using curvature estimation.

Science.gov (United States)

Jones, Michael D; Farley, McKay; Butler, Joseph; Beardall, Matthew

2010-01-01

We address the problem of directable weathering of exposed concave rock for use in computer-generated animation or games. Previous weathering models that admit concave surfaces are computationally inefficient and difficult to control. In nature, the spheroidal and cavernous weathering rates depend on the surface curvature. Spheroidal weathering is fastest in areas with large positive mean curvature and cavernous weathering is fastest in areas with large negative mean curvature. We simulate both processes using an approximation of mean curvature on a voxel grid. Both weathering rates are also influenced by rock durability. The user controls rock durability by editing a durability graph before and during weathering simulation. Simulations of rockfall and colluvium deposition further improve realism. The profile of the final weathered rock matches the shape of the durability graph up to the effects of weathering and colluvium deposition. We demonstrate the top-down directability and visual plausibility of the resulting model through a series of screenshots and rendered images. The results include the weathering of a cube into a sphere and of a sheltered inside corner into a cavern as predicted by the underlying geomorphological models.

Processing convexity and concavity along a 2-D contour: figure-ground, structural shape, and attention.

Science.gov (United States)

Bertamini, Marco; Wagemans, Johan

2013-04-01

Interest in convexity has a long history in vision science. For smooth contours in an image, it is possible to code regions of positive (convex) and negative (concave) curvature, and this provides useful information about solid shape. We review a large body of evidence on the role of this information in perception of shape and in attention. This includes evidence from behavioral, neurophysiological, imaging, and developmental studies. A review is necessary to analyze the evidence on how convexity affects (1) separation between figure and ground, (2) part structure, and (3) attention allocation. Despite some broad agreement on the importance of convexity in these areas, there is a lack of consensus on the interpretation of specific claims--for example, on the contribution of convexity to metric depth and on the automatic directing of attention to convexities or to concavities. The focus is on convexity and concavity along a 2-D contour, not convexity and concavity in 3-D, but the important link between the two is discussed. We conclude that there is good evidence for the role of convexity information in figure-ground organization and in parsing, but other, more specific claims are not (yet) well supported.

Irradiation of target volumes with concave outlines

Energy Technology Data Exchange (ETDEWEB)

De Neve, W; Fortan, L; Derycke, S; Van Duyse, B; DE Wagter, C [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde

1995-12-01

A heuristic planning procedure allowing to obtain a 3-dimensional conformal dose distribution for target volumes with concavities has been investigated. The procedure divides the planning problem into a number of sub-problems each solvable by known methods. By patching together the solutions to the sub-problems, a solution with a predictable dosimetric outcome can be obtained. The procedure can be applied to most 3-dimensional systems. The procedure is described and its applications to the irradiation of neoplasms are discussed. (A.S.).

Irradiation of target volumes with concave outlines

International Nuclear Information System (INIS)

De Neve, W.; Fortan, L.; Derycke, S.; Van Duyse, B.; DE Wagter, C.

1995-01-01

A heuristic planning procedure allowing to obtain a 3-dimensional conformal dose distribution for target volumes with concavities has been investigated. The procedure divides the planning problem into a number of sub-problems each solvable by known methods. By patching together the solutions to the sub-problems, a solution with a predictable dosimetric outcome can be obtained. The procedure can be applied to most 3-dimensional systems. The procedure is described and its applications to the irradiation of neoplasms are discussed. (A.S.)

Nanoscale aluminum concaves for light-trapping in organic thin-films

DEFF Research Database (Denmark)

Goszczak, Arkadiusz Jaroslaw; Adam, Jost; Cielecki, Pawel Piotr

2016-01-01

Anodic aluminum oxide (AAO) templates, fabricated from oxalic acid and phosphoric acid, lead to non-periodic nanoscale concave structures in their underlying aluminum layer, which are investigated for their field-enhancement properties by applying a thin-film polymer coating based laser ablation...

Sensitive visual test for concave diffraction gratings.

Science.gov (United States)

Bruner, E. C., Jr.

1972-01-01

A simple visual test for the evaluation of concave diffraction gratings is described. It is twice as sensitive as the Foucault knife edge test, from which it is derived, and has the advantage that the images are straight and free of astigmatism. It is particularly useful for grating with high ruling frequency where the above image faults limit the utility of the Foucault test. The test can be interpreted quantitatively and can detect zonal grating space errors of as little as 0.1 A.

Endophthalmitis after descemet stripping endothelial keratoplasty with concave-oriented dislocation on slit-lamp optical coherence topography.

Science.gov (United States)

Kaiura, Terry L; Ritterband, David C; Koplin, Richard S; Shih, Carolyn; Palmierto, Pat M; Seedor, John A

2010-02-01

To present the first reported case of Descemet membrane stripping endothelial keratoplasty (DSEK)-associated endophthalmitis with concave dislocation on slit-lamp optical coherence topography (SL-OCT). An 86-year-old man underwent DSEK for corneal decompensation secondary to prior surgery. On all postoperative visits, a slit-lamp examination and SL-OCT were performed. On the first postoperative day, the lenticle was dislocated in a concave configuration as imaged with the SL-OCT. On the second postoperative day, the patient had eye pain, nausea, and increased intraocular pressure. On SL-OCT imaging, the concave configuration and fibrin stranding were imaged. With intraocular pressure lowering, the patient's pain subsided, and he was scheduled for a lenticle refloat the following day. The next day, endophthalmitis was diagnosed secondary to exuberant purulent inflammation. At surgery, the lenticle was removed, cultures were obtained, and pars plana vitrectomy and intravitreal injections were administered. Intraoperative cultures were positive for heavy growth of Streptococcus pneumoniae. Endophthalmitis is a potential complication for any intraocular procedure including DSEK. SL-OCT imaging postoperatively may reveal concave lenticle configuration and subtle anterior chamber fibrin stranding may be early sign of endophthalmitis.

An analytic solution for calculating the beam intensity profiles useful to irradiate target volumes with bi-concave outlines

Energy Technology Data Exchange (ETDEWEB)

De Neve, W; Derycke, S; De Wagter, C [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde

1995-12-01

A heuristic planing procedure allowing to obtain a 3-dimensional conformal dose distribution in radiotherapy for target volumes with a bi-concave or multi-concave shape has been developed. The described method is tested on a phantom simulating a pelvic target, described by Brahme.

Navier-Stokes Computations With One-Equation Turbulence Model for Flows Along Concave Wall Surfaces

Science.gov (United States)

Wang, Chi R.

2005-01-01

This report presents the use of a time-marching three-dimensional compressible Navier-Stokes equation numerical solver with a one-equation turbulence model to simulate the flow fields developed along concave wall surfaces without and with a downstream extension flat wall surface. The 3-D Navier- Stokes numerical solver came from the NASA Glenn-HT code. The one-equation turbulence model was derived from the Spalart and Allmaras model. The computational approach was first calibrated with the computations of the velocity and Reynolds shear stress profiles of a steady flat plate boundary layer flow. The computational approach was then used to simulate developing boundary layer flows along concave wall surfaces without and with a downstream extension wall. The author investigated the computational results of surface friction factors, near surface velocity components, near wall temperatures, and a turbulent shear stress component in terms of turbulence modeling, computational mesh configurations, inlet turbulence level, and time iteration step. The computational results were compared with existing measurements of skin friction factors, velocity components, and shear stresses of the developing boundary layer flows. With a fine computational mesh and a one-equation model, the computational approach could predict accurately the skin friction factors, near surface velocity and temperature, and shear stress within the flows. The computed velocity components and shear stresses also showed the vortices effect on the velocity variations over a concave wall. The computed eddy viscosities at the near wall locations were also compared with the results from a two equation turbulence modeling technique. The inlet turbulence length scale was found to have little effect on the eddy viscosities at locations near the concave wall surface. The eddy viscosities, from the one-equation and two-equation modeling, were comparable at most stream-wise stations. The present one

Concave utility, transaction costs, and risk in measuring discounting of delayed rewards.

Science.gov (United States)

Kirby, Kris N; Santiesteban, Mariana

2003-01-01

Research has consistently found that the decline in the present values of delayed rewards as delay increases is better fit by hyperbolic than by exponential delay-discounting functions. However, concave utility, transaction costs, and risk each could produce hyperbolic-looking data, even when the underlying discounting function is exponential. In Experiments 1 (N = 45) and 2 (N = 103), participants placed bids indicating their present values of real future monetary rewards in computer-based 2nd-price auctions. Both experiments suggest that utility is not sufficiently concave to account for the superior fit of hyperbolic functions. Experiment 2 provided no evidence that the effects of transaction costs and risk are large enough to account for the superior fit of hyperbolic functions.

Quantitative test for concave aspheric surfaces using a Babinet compensator.

Science.gov (United States)

Saxena, A K

1979-08-15

A quantitative test for the evaluation of surface figures of concave aspheric surfaces using a Babinet compensator is reported. A theoretical estimate of the sensitivity is 0.002lambda for a minimum detectable phase change of 2 pi x 10(-3) rad over a segment length of 1.0 cm.

1-concave basis for TU games and the library game

NARCIS (Netherlands)

Driessen, Theo; Khmelnitskaya, Anna Borisovna; Sales, J.

2012-01-01

The study of 1-convex/1-concave TU games possessing a nonempty core and for which the nucleolus is linear was initiated by Driessen and Tijs (Methods Oper. Res. 46:395–406, 1983) and Driessen (OR Spectrum 7:19–26, 1985). However, until recently appealing abstract and practical examples of these

Integration of polystyrene microlenses with both convex and concave profiles in a polymer-based microfluidic system

KAUST Repository

Fan, Yiqiang

2013-12-20

This paper reports a new technique of fabricating polystyrene microlenses with both convex and concave profiles that are integrated in polymer-based microfluidic system. The polystyrene microlenses, or microlens array, are fabricated using the free-surface thermal compression molding method. The laser fabricated poly(methyl methacrylate) (PMMA) sheet is used as the mold for the thermal compression molding process. With different surface treatment methods of the PMMA mold, microlenses with either convex or concave profiles could be achieved during the thermal molding process. By integrating the microlenses in the microfluidic systems, observing the flow inside the microchannels is easier. This new technique is rapid, low cost, and it does not require cleanroom facilities. Microlenses with both convex and concave profiles can be easily fabricated and integrated in microfluidic system with this technique. © 2013 Springer-Verlag Berlin Heidelberg.

Pt3Co concave nanocubes: synthesis, formation understanding, and enhanced catalytic activity toward hydrogenation of styrene.

Science.gov (United States)

Wang, Chenyu; Lin, Cuikun; Zhang, Lihua; Quan, Zewei; Sun, Kai; Zhao, Bo; Wang, Feng; Porter, Nathan; Wang, Yuxuan; Fang, Jiye

2014-02-03

We report a facile synthesis route to prepare high-quality Pt3Co nanocubes with a concave structure, and further demonstrate that these concave Pt3Co nanocubes are terminated with high-index crystal facets. The success of this preparation is highly dependent on an appropriate nucleation process with a successively anisotropic overgrowth and a preservation of the resultant high-index planes by control binding of oleyl-amine/oleic acid with a fine-tuned composition. Using a hydrogenation of styrene as a model reaction, these Pt3Co concave nanocubes as a new class of nanocatalysts with more open structure and active atomic sites located on their high-index crystallographic planes exhibit an enhanced catalytic activity in comparison with low-indexed surface terminated Pt3Co nanocubes in similar size. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Successor Function and Pareto Optimal Solutions of Cooperative Differential Systems with Concavity. I

DEFF Research Database (Denmark)

Andersen, Kurt Munk; Sandqvist, Allan

1997-01-01

We investigate the domain of definition and the domain of values for the successor function of a cooperative differential system x'=f(t,x), where the coordinate functions are concave in x for any fixed value of t. Moreover, we give a characterization of a weakly Pareto optimal solution.......We investigate the domain of definition and the domain of values for the successor function of a cooperative differential system x'=f(t,x), where the coordinate functions are concave in x for any fixed value of t. Moreover, we give a characterization of a weakly Pareto optimal solution....

Apparatus including concave reflectors and a line of optical fibers

International Nuclear Information System (INIS)

Dolan, J.T.

1992-01-01

This patent describes an apparatus including a radiation source which emits in a multiplicity of directions for focusing radiation on an object which may receive radiation within a certain solid angle. It comprises a first reflector and a second reflector, the first reflector being elliptical in cross section and having a first focus and a second focus, the second reflector being circular in cross section and having a center, and a radius equal to the distance between the second reflector and the first focus, the first reflector and the second reflector being arranged so that a concave reflecting surface of the first reflector faces a concave reflecting surface of the second reflector, and so arranged that the first focus of the first reflector corresponds to the center of the second reflector, the radiation source being an elongated discharge bulb, the object being a group of two or more optical fibers defining at least one line of optical fibers which are located at the second focus of the first reflector

Monotonicity and Logarithmic Concavity of Two Functions Involving Exponential Function

Science.gov (United States)

Liu, Ai-Qi; Li, Guo-Fu; Guo, Bai-Ni; Qi, Feng

2008-01-01

The function 1 divided by "x"[superscript 2] minus "e"[superscript"-x"] divided by (1 minus "e"[superscript"-x"])[superscript 2] for "x" greater than 0 is proved to be strictly decreasing. As an application of this monotonicity, the logarithmic concavity of the function "t" divided by "e"[superscript "at"] minus "e"[superscript"(a-1)""t"] for "a"…

Au@Pd core-shell nanobricks with concave structures and their catalysis of ethanol oxidation.

Science.gov (United States)

Wang, Wenjin; Zhang, Jie; Yang, Shengchun; Ding, Bingjun; Song, Xiaoping

2013-10-01

Au@Pd core-shell nanobricks (CNBs) with concave surfaces and Pd shells with a thickness of approximately 5 nm were synthesized by co-reduction of HAuCl4 and H2 PdCl4 in the presence of Au seeds and Ag ions. These as-synthesized concave CNBs exhibit significantly enhanced catalytic activity for the electrooxidation of ethanol in alkaline media compared to the commercially-used Pd black. The improved performance of the Au@Pd CNBs can be attributed to the exposed stepped surfaces, high-index facets, and the synergistic effects of the core and shell metals. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A facile method to fabricate close-packed concave microlens array on cylindrical glass

International Nuclear Information System (INIS)

Deng, Zefang; Chen, Feng; Yang, Qing; Liu, Hewei; Bian, Hao; Du, Guangqing; Hu, Yang; Si, Jinhai; Meng, Xiangwei; Hou, Xun

2012-01-01

This work presents a facile method to fabricate concave microlens arrays (MLAs) with controllable shape and high fill factor on cylindrical silica glass by a femtosecond laser-enhanced chemical wet etching process. The hexagonal and rectangular MLAs are flexibly fabricated on the silica glass cylinder with a diameter of 3 mm. The morphological characteristics of MLAs are measured by a scanning electron microscope and a laser scanning confocal microscope. The measurements show that the good uniformity and high packing density MLA structures are generated. It has also been demonstrated that the shape and size of the concave structures could be easily tuned by changing laser power and the arrangement of laser exposure spots. The convex MLAs replicated by the polymer casting method experience excellent image quality. (paper)

Theoretical fringe profiles with crossed Babinet compensators in testing concave aspheric surfaces.

Science.gov (United States)

Saxena, A K; Lancelot, J P

1982-11-15

This paper presents the theory for the use of crossed Babinet compensators in testing concave aspheric surfaces. Theoretical fringe profiles for a sphere and for an aspheric surface with primary aberration are shown. Advantages of this method are discussed.

The near-field acoustic levitation for spheres by transducer with concave spherical radiating surface

International Nuclear Information System (INIS)

Liu, Jian Fang; Sun, Xu Guang; Jiao, Xiao Yang; Chen, Hong Xia; Hua, Shun Ming; Zhang, Hong Chun

2013-01-01

To levitate ICF target spheres in the near-field acoustic levitation, a transducer with concave spherical radiating surface and a nearfield acoustic levitation system is established. The concave spherical radiating surface of the transducer is designed by the finite element parametric method. Then the levitation height and levitation perturbation of spheres with different mass and diameters in the near-field acoustic levitation system are tested and discussed in the driving voltage at 400V, 500V and 600V, respectively, when the levitation system is under the resonant frequency. Finally, based on the experimental results, the height formula of the near-field acoustic levitation for spheres is deduced by introducing a coupling coefficient.

The near-field acoustic levitation for spheres by transducer with concave spherical radiating surface

Energy Technology Data Exchange (ETDEWEB)

Liu, Jian Fang; Sun, Xu Guang; Jiao, Xiao Yang; Chen, Hong Xia [Jilin University, Changchun (China); Hua, Shun Ming [Zhejiang University, Ningbo (China); Zhang, Hong Chun [Aviation University of AirForce, Changchun (China)

2013-02-15

To levitate ICF target spheres in the near-field acoustic levitation, a transducer with concave spherical radiating surface and a nearfield acoustic levitation system is established. The concave spherical radiating surface of the transducer is designed by the finite element parametric method. Then the levitation height and levitation perturbation of spheres with different mass and diameters in the near-field acoustic levitation system are tested and discussed in the driving voltage at 400V, 500V and 600V, respectively, when the levitation system is under the resonant frequency. Finally, based on the experimental results, the height formula of the near-field acoustic levitation for spheres is deduced by introducing a coupling coefficient.

A Lower Bound on the Differential Entropy of Log-Concave Random Vectors with Applications

Directory of Open Access Journals (Sweden)

Arnaud Marsiglietti

2018-03-01

Full Text Available We derive a lower bound on the differential entropy of a log-concave random variable X in terms of the p-th absolute moment of X. The new bound leads to a reverse entropy power inequality with an explicit constant, and to new bounds on the rate-distortion function and the channel capacity. Specifically, we study the rate-distortion function for log-concave sources and distortion measure d ( x , x ^ = | x − x ^ | r , with r ≥ 1 , and we establish that the difference between the rate-distortion function and the Shannon lower bound is at most log ( π e ≈ 1 . 5 bits, independently of r and the target distortion d. For mean-square error distortion, the difference is at most log ( π e 2 ≈ 1 bit, regardless of d. We also provide bounds on the capacity of memoryless additive noise channels when the noise is log-concave. We show that the difference between the capacity of such channels and the capacity of the Gaussian channel with the same noise power is at most log ( π e 2 ≈ 1 bit. Our results generalize to the case of a random vector X with possibly dependent coordinates. Our proof technique leverages tools from convex geometry.

Environmental protection stability of river bed and banks using convex, concave, and linear bed sills.

Science.gov (United States)

Keshavarzi, Alireza; Noori, Lila Khaje

2010-12-01

River bed scourings are a major environmental problem for fish and aquatic habitat resources. In this study, to prevent river bed and banks from scouring, different types of bed sills including convex, concave and linear patterns were installed in a movable channel bed in a laboratory flume. The bed sills were tested with nine different arrangements and under different flow conditions. To find the most effective bed sill pattern, the scouring depth was measured downstream of the bed sill for a long experimental duration. The scour depth was measured at the middle and at the end of each experimental test for different ratios of the arch radius to the channel width [r/w]. The experimental results indicated that the convex pattern with r/w=0.35 produced minimum bed scouring depth at the center line whereas the concave pattern with r/w=0.23 produced the minimum scour depth at the wall banks. Therefore, the convex pattern was the most effective configuration for prevention of scouring at the center line of the river while the concave pattern was very effective to prevent scouring at the river banks. These findings can be suggested to be used in practical applications.

Singular elliptic systems involving concave terms and critical Caffarelli-Kohn-Nirenberg exponents

Directory of Open Access Journals (Sweden)

Mohammed E. O. El Mokhtar

2012-03-01

Full Text Available In this article, we establish the existence of at least four solutions to a singular system with a concave term, a critical Caffarelli-Kohn-Nirenberg exponent, and sign-changing weight functions. Our main tools are the Nehari manifold and the mountain pass theorem.

Pierce-type electron gun with a large concave LaB6 cathode

International Nuclear Information System (INIS)

Shintake, Tumoru; Ohba, Kunio; Matoba, Masaru; Katase, Akira

1981-01-01

A Pierce-type electron gun with a concave cathode of lanthanum hexaboride (LaB 6 ) 30 mm in diameter is described. At an accelerating voltage of 3 kV and a cathode temperature of 1340 0 C, a focussed electron beam of DC 300 mA was obtained. (author)

The Scallop's Eye--A Concave Mirror in the Context of Biology

Science.gov (United States)

Colicchia, Giuseppe; Waltner, Christine; Hopf, Martin; Wiesner, Hartmut

2009-01-01

Teaching physics in the context of medicine or biology is a way to generate students' interest in physics. A more uncommon type of eye, the scallop's eye (an eye with a spherical concave mirror, which is similar to a Newtonian or Schmidt telescope) and the image-forming mechanism in this eye are described. Also, a simple eye model, which can…

Partial null astigmatism-compensated interferometry for a concave freeform Zernike mirror

Science.gov (United States)

Dou, Yimeng; Yuan, Qun; Gao, Zhishan; Yin, Huimin; Chen, Lu; Yao, Yanxia; Cheng, Jinlong

2018-06-01

Partial null interferometry without using any null optics is proposed to measure a concave freeform Zernike mirror. Oblique incidence on the freeform mirror is used to compensate for astigmatism as the main component in its figure, and to constrain the divergence of the test beam as well. The phase demodulated from the partial nulled interferograms is divided into low-frequency phase and high-frequency phase by Zernike polynomial fitting. The low-frequency surface figure error of the freeform mirror represented by the coefficients of Zernike polynomials is reconstructed from the low-frequency phase, applying the reverse optimization reconstruction technology in the accurate model of the interferometric system. The high-frequency surface figure error of the freeform mirror is retrieved from the high-frequency phase adopting back propagating technology, according to the updated model in which the low-frequency surface figure error has been superimposed on the sag of the freeform mirror. Simulations verified that this method is capable of testing a wide variety of astigmatism-dominated freeform mirrors due to the high dynamic range. The experimental result using our proposed method for a concave freeform Zernike mirror is consistent with the null test result employing the computer-generated hologram.

Modeling of Focused Acoustic Field of a Concave Multi-annular Phased Array Using Spheroidal Beam Equation

Science.gov (United States)

Yu, Li-Li; Shou, Wen-De; Hui, Chun

2012-02-01

A theoretical model of focused acoustic field for a multi-annular phased array on concave spherical surface is proposed. In this model, the source boundary conditions of the spheroidal beam equation (SBE) for multi-annular phased elements are studied. Acoustic field calculated by the dynamic focusing model of SBE is compared with numerical results of the O'Neil and Khokhlov—Zabolotskaya—Kuznetsov (KZK) model, respectively. Axial dynamic focusing and the harmonic effects are presented. The results demonstrate that the dynamic focusing model of SBE is good valid for a concave multi-annular phased array with a large aperture angle in the linear or nonlinear field.

Reproducible and recyclable SERS substrates: Flower-like Ag structures with concave surfaces formed by electrodeposition

Science.gov (United States)

Bian, Juncao; Shu, Shiwei; Li, Jianfu; Huang, Chao; Li, Yang Yang; Zhang, Rui-Qin

2015-04-01

Direct synthesis of three-dimensional Ag structures on solid substrates for the purposes of producing reproducible and recyclable surface-enhanced Raman scattering (SERS) applications remains challenging. In this work, flower-like Ag structures with concave surfaces (FACS) were successfully electrodeposited onto ITO glass using the double-potentiostatic method. The FACS, with an enhancement factor of the order of 108, exhibited a SERS signal intensity 3.3 times stronger than that measured from Ag nanostructures without concave surfaces. A cleaning procedure involving lengthy immersion of the sample in ethanol and KNO3 was proposed to recycle the substrate and confirmed by using rhodamine 6G, adenine, and 4-aminothiophenol as target molecules. The findings can help to advance the practical applications of Ag nanostructure-based SERS substrates.

Assessment of CHF enhancement mechanisms in a curved, rectangular channel subjected to concave heating

International Nuclear Information System (INIS)

Sturgis, J.C.; Mudawar, I.

1999-01-01

An experimental study was undertaken to examine the enhancement in critical heat flux (CHF) provided by streamwise curvature. Curved and straight rectangular flow channels were fabricated with identical 5.0 x 2.5 mm cross sections and heated lengths of 101.6 mm in which the heat was applied to only one wall--the concave wall (32.3 mm radius) in the curved channel and a side wall in the straight. Tests were conducted using FC-72 liquid with mean inlet velocity and outlet subcooling of 0.25 to 10 m s -1 and 3 to 29 C, respectively. Centripetal acceleration for curved flow reached 315 times earth's gravitational acceleration. Critical heat flux was enhanced due to flow curvature at all conditions but the enhancement decreased with increasing subcooling. For near-saturated conditions, the enhancement was approximately 60% while for highly subcooled flow it was only 20%. The causes for the enhancement were identified as (1) increased pressure on the liquid-vapor interface at wetting fronts, (2) buoyancy forces and (3) increased subcooling at the concave wall. Flow visualization tests were conducted in transparent channels to explore the role of buoyancy forces in enhancing the critical heat flux. These forces were observed to remove vapor from the concave wall and distribute it throughout the cross section. Vapor removal was only effective at near-saturated conditions, yielding the observed substantial enhancement in CHF relative to the straight channel

Site-Selective Carving and Co-Deposition: Transformation of Ag Nanocubes into Concave Nanocrystals Encased by Au-Ag Alloy Frames.

Science.gov (United States)

Ahn, Jaewan; Wang, Daniel; Ding, Yong; Zhang, Jiawei; Qin, Dong

2018-01-23

We report a facile synthesis of Ag nanocubes with concave side faces and Au-Ag alloy frames, namely Ag@Au-Ag concave nanocrystals, by titrating HAuCl 4 solution into an aqueous mixture of Ag nanocubes, ascorbic acid (H 2 Asc), NaOH, and cetyltrimethylammonium chloride (CTAC) at an initial pH of 11.6 under ambient conditions. Different from all previous studies involving poly(vinylpyrrolidine), the use of CTAC at a sufficiently high concentration plays an essential role in carving away Ag atoms from the side faces through galvanic replacement. Concurrent co-deposition of Au and Ag atoms via chemical reduction at orthogonal sites on the surface of Ag nanocubes leads to the generation of Ag@Au-Ag concave nanocrystals with well-defined and controllable structures. Specifically, in the presence of CTAC-derived Cl - ions, the titrated HAuCl 4 is maintained in the AuCl 4 - species, enabling its galvanic replacement with the Ag atoms located on the side faces of nanocubes. The released Ag + ions can be retained in the soluble form of AgCl 2 - by complexing with the Cl - ions. Both the AuCl 4 - and AgCl 2 - in the solution are then reduced by ascorbate monoanion, a product of the neutralization reaction between H 2 Asc and NaOH, to Au and Ag atoms for their preferential co-deposition onto the edges and corners of the Ag nanocubes. Compared with Ag nanocubes, the Ag@Au-Ag concave nanocrystals exhibit much stronger SERS activity at an excitation of 785 nm, making it feasible to monitor the Au-catalyzed reduction of 4-nitrothiophenol by NaBH 4 in situ. When the Ag cores are removed, the concave nanocrystals evolve into Au-Ag nanoframes with controllable ridge thicknesses.

Modeling of Focused Acoustic Field of a Concave Multi-annular Phased Array Using Spheroidal Beam Equation

International Nuclear Information System (INIS)

Yu Lili; Shou Wende; Hui Chun

2012-01-01

A theoretical model of focused acoustic field for a multi-annular phased array on concave spherical surface is proposed. In this model, the source boundary conditions of the spheroidal beam equation (SBE) for multi-annular phased elements are studied. Acoustic field calculated by the dynamic focusing model of SBE is compared with numerical results of the O'Neil and Khokhlov-Zabolotskaya-Kuznetsov (KZK) model, respectively. Axial dynamic focusing and the harmonic effects are presented. The results demonstrate that the dynamic focusing model of SBE is good valid for a concave multi-annular phased array with a large aperture angle in the linear or nonlinear field. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Surface tension-induced high aspect-ratio PDMS micropillars with concave and convex lens tips

KAUST Repository

Li, Huawei; Fan, Yiqiang; Yi, Ying; Foulds, Ian G.

2013-01-01

This paper reports a novel method for the fabrication of 3-dimensional (3D) Polydimethylsiloxane (PDMS) micropillars with concave and convex lens tips in a one-step molding process, using a CO2 laser-machined Poly(methyl methacrylate) (PMMA) mold with through holes. The PDMS micropillars are 4 mm high and have an aspect ratio of 251. The micropillars are formed by capillary force drawing up PDMS into the through hole mold. The concave and convex lens tips of the PDMS cylindrical micropillars are induced by surface tension and are controllable by changing the surface wetting properties of the through holes in the PMMA mold. This technique eliminates the requirements of expensive and complicated facilities to prepare a 3D mold, and it provides a simple and rapid method to fabricate 3D PDMS micropillars with controllable dimensions and tip shapes. © 2013 IEEE.

Surface tension-induced high aspect-ratio PDMS micropillars with concave and convex lens tips

KAUST Repository

Li, Huawei

2013-04-01

This paper reports a novel method for the fabrication of 3-dimensional (3D) Polydimethylsiloxane (PDMS) micropillars with concave and convex lens tips in a one-step molding process, using a CO2 laser-machined Poly(methyl methacrylate) (PMMA) mold with through holes. The PDMS micropillars are 4 mm high and have an aspect ratio of 251. The micropillars are formed by capillary force drawing up PDMS into the through hole mold. The concave and convex lens tips of the PDMS cylindrical micropillars are induced by surface tension and are controllable by changing the surface wetting properties of the through holes in the PMMA mold. This technique eliminates the requirements of expensive and complicated facilities to prepare a 3D mold, and it provides a simple and rapid method to fabricate 3D PDMS micropillars with controllable dimensions and tip shapes. © 2013 IEEE.

On the impact of a concave nosed axisymmetric body on a free surface

NARCIS (Netherlands)

Mathai, Varghese; Govardhan, R.N.; Arakeri, V.H.

2015-01-01

We report on an experimental study of the vertical impact of a concave nosed axisymmetric body on a free surface. Previous studies have shown that bodies with a convex nose, like a sphere, produce a well defined splash with a relatively large cavity behind the model. In contrast, we find that with a

Polarization of concave domains by traveling wave pinning.

Directory of Open Access Journals (Sweden)

Slawomir Bialecki

Full Text Available Pattern formation is one of the most fundamental yet puzzling phenomena in physics and biology. We propose that traveling front pinning into concave portions of the boundary of 3-dimensional domains can serve as a generic gradient-maintaining mechanism. Such a mechanism of domain polarization arises even for scalar bistable reaction-diffusion equations, and, depending on geometry, a number of stationary fronts may be formed leading to complex spatial patterns. The main advantage of the pinning mechanism, with respect to the Turing bifurcation, is that it allows for maintaining gradients in the specific regions of the domain. By linking the instant domain shape with the spatial pattern, the mechanism can be responsible for cellular polarization and differentiation.

On the equivalence of the Choquet, pan- and concave integrals on finite spaces

Czech Academy of Sciences Publication Activity Database

Ouyang, Y.; Li, J.; Mesiar, Radko

2017-01-01

Roč. 456, č. 1 (2017), s. 151-162 ISSN 0022-247X Institutional support: RVO:67985556 Keywords : (M)-property * Choquet integral * Concave integral * Minimal atom * Monotone measure * Pan-integral Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.064, year: 2016 http://library.utia.cas.cz/separaty/2017/E/mesiar-0477091.pdf

Cubierta con elementos prefabricados de hormigón armado y pretensado, en Villanova de Asti, Italia

Directory of Open Access Journals (Sweden)

Nicola, S.

1969-09-01

Full Text Available This building is part of an industrial complex, owned by the firm FIRGAT. In spite of its relatively small size, it is notable because of its roof, which rests on normal reinforced concrete pillars. The roofing consists of three kinds of precast elements, some concave, others convex and the main girders. The whole is interconnected in an original manner, following the calculations of engineer Antonio Migliasso.Este edificio constituye parte del complejo industrial de la sociedad FIRGAT y, a pesar de sus dimensiones relativamente pequeñas, es notable por el sistema de cubierta adoptado: sobre pilares de hormigón armado normal se apoyan los elementos de cobertura, prefabricados, de tres clases (cóncavos, convexos y vigas principales y enlazados de forma original, según los cálculos y proyecto del ingeniero Antonio Migliasso.

Iris concavity, corneal biomechanics, and their correlations with ocular biometry in a cohort of 10- to 12-year-old UK school boys: baseline data.

Science.gov (United States)

Shah, Ameet; Low, Sancy; Garway-Heath, David F; Foster, Paul J; Barton, Keith

2014-04-17

Pigment dispersion syndrome is associated with iris concavity. This study investigated the prevalence of iris concavity, defined as a measurement of ≤-0.1 mm, in a cohort of 10- to 12-year-old boys, and explored the relationship between iris curvature and anterior segment biometry. Associations with corneal biomechanical parameters also were explored. A cohort of school boys (n = 96) was recruited from a local school. Anterior segment optical coherence tomography (AS-OCT) was performed under accommodative and nonaccommodative conditions, and iris curvature quantified. Corneal hysteresis (CH) and corneal resistance factor (CRF) were measured with the ocular response analyzer (ORA). Noncontact axial biometry was performed using laser interferometry. The prevalence of iris concavity was 24% on distance fixation, increasing to 65% on accommodation. Variables significantly associated with nonaccommodating iris curvature were lens vault (P = 0.02) and mean keratometry (P = 0.02). For both variables acting jointly, R(2) = 0.30. Variables associated significantly with accommodating iris curvature were anterior chamber depth (P = 0.009), lens vault (P = 0.049), and mean scleral spur angle (P Iris concavity was a common finding in this cohort and related to anterior segment biometric parameters. Further work is required to clarify whether anatomical differences exist between iris concavity seen in the adolescent eye and that found in adults with pigment dispersion syndrome. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Integration of polystyrene microlenses with both convex and concave profiles in a polymer-based microfluidic system

KAUST Repository

Fan, Yiqiang; Li, Huawei; Foulds, Ian G.

2013-01-01

This paper reports a new technique of fabricating polystyrene microlenses with both convex and concave profiles that are integrated in polymer-based microfluidic system. The polystyrene microlenses, or microlens array, are fabricated using the free

Visualizing RNA Secondary Structure Base Pair Binding Probabilities using Nested Concave Hulls

OpenAIRE

Sansen , Joris; Bourqui , Romain; Thebault , Patricia; Allali , Julien; Auber , David

2015-01-01

International audience; The challenge 1 of the BIOVIS 2015 design contest consists in designing an intuitive visual depiction of base pairs binding probabilities for secondary structure of ncRNA. Our representation depicts the potential nucleotide pairs binding using nested concave hulls over the computed MFE ncRNA secondary structure. Thus, it allows to identify regions with a high level of uncertainty in the MFE computation and the structures which seem to match to reality.

Synthesis of Au@Pt bimetallic nanoparticles with concave Au nanocuboids as seeds and their enhanced electrocatalytic properties in the ethanol oxidation reaction

Science.gov (United States)

Tan, Lingyu; Li, Lidong; Peng, Yi; Guo, Lin

2015-12-01

Herein, a new type of uniform and well-structured Au@Pt bimetallic nanoparticles (BNPs) with highly active concave Au nanocuboids (NCs) as seeds was successfully synthesized by using the classic seed-mediated method. Electrochemical measurements were conducted to demonstrate their greatly enhanced catalytic performance in the ethanol oxidation reaction (EOR). It was found that the electrochemical performance for Au@Pt BNPs with the concave Au NCs as seeds, which were enclosed by {611} high-index facets, could be seven times higher than that of the Au@Pt bimetallic nanoparticles with regular spherical Au NPs as seeds. Furthermore, our findings show that the morphology and electrocatalytic activity of the Au@Pt BNPs can be tuned simply by changing the compositional ratios of the growth solution. The lower the amount of H2PtCl6 used in the growth solution, the thinner the Pt shell grew, and the more high-index facets of concave Au NCs seeds were exposed in Au@Pt BNPs, leading to higher electrochemical activity. These as-prepared concave Au@Pt BNPs will open up new strategies for improving catalytic efficiency and reducing the use of the expensive and scarce resource of platinum in the ethanol oxidation reaction, and are potentially applicable as electrochemical catalysts for direct ethanol fuel cells.

Synthesis of Au@Pt bimetallic nanoparticles with concave Au nanocuboids as seeds and their enhanced electrocatalytic properties in the ethanol oxidation reaction

International Nuclear Information System (INIS)

Tan, Lingyu; Li, Lidong; Peng, Yi; Guo, Lin

2015-01-01

Herein, a new type of uniform and well-structured Au@Pt bimetallic nanoparticles (BNPs) with highly active concave Au nanocuboids (NCs) as seeds was successfully synthesized by using the classic seed-mediated method. Electrochemical measurements were conducted to demonstrate their greatly enhanced catalytic performance in the ethanol oxidation reaction (EOR). It was found that the electrochemical performance for Au@Pt BNPs with the concave Au NCs as seeds, which were enclosed by {611}high-index facets, could be seven times higher than that of the Au@Pt bimetallic nanoparticles with regular spherical Au NPs as seeds. Furthermore, our findings show that the morphology and electrocatalytic activity of the Au@Pt BNPs can be tuned simply by changing the compositional ratios of the growth solution. The lower the amount of H_2PtCl_6 used in the growth solution, the thinner the Pt shell grew, and the more high-index facets of concave Au NCs seeds were exposed in Au@Pt BNPs, leading to higher electrochemical activity. These as-prepared concave Au@Pt BNPs will open up new strategies for improving catalytic efficiency and reducing the use of the expensive and scarce resource of platinum in the ethanol oxidation reaction, and are potentially applicable as electrochemical catalysts for direct ethanol fuel cells. (paper)

Noninvasive radioisotopic technique for detection of platelet deposition in mitral valve prostheses and quantitation of visceral microembolism in dogs

International Nuclear Information System (INIS)

Dewanjee, M.K.; Fuster, V.; Rao, S.A.; Forshaw, P.L.; Kaye, M.P.

1983-01-01

A noninvasive technique has been developed in the dog model for imaging, with a gamma camera, the platelet deposition on Bjoerk-Shiley mitral valve prostheses early postoperatively. At 25 hours after implantation of the prosthesis and 24 hours after intravenous administration of 400 to 500 microCi of platelets labeled with indium-111, the platelet deposition in the sewing ring and perivalvular cardiac tissue can be clearly delineated in a scintiphotograph. An in vitro technique was also developed for quantitation of visceral microemboli in brain, lungs, kidneys, and other tissues. Biodistribution of the labeled platelets was quantitated, and the tissue/blood radioactivity ratio was determined in 22 dogs in four groups: unoperated normal dogs, sham-operated dogs, prosthesis-implanted dogs, and prosthesis-implanted dogs treated with dipyridamole before and aspirin and dipyridamole immediately after operation. Fifteen to 20% of total platelets were consumed as a consequence of the surgical procedure. On quantitation, we found that platelet deposition on the components of the prostheses was significantly reduced in prosthesis-implanted animals treated with dipyridamole and aspirin when compared with prosthesis-implanted, untreated dogs. All prosthesis-implanted animals considered together had a twofold to fourfold increase in tissue/blood radioactivity ratio in comparison with unoperated and sham-operated animals, an indication that the viscera work as filters and trap platelet microemboli that are presumably produced in the region of the mitral valve prostheses. In the dog model, indium-111-labeled platelets thus provide a sensitive marker for noninvasive imaging of platelet deposition on mechanical mitral valve prostheses, in vitro evaluation of platelet microembolism in viscera, in vitro quantitation of surgical consumption of platelets, and evaluation of platelet-inhibitor drugs

Transient river response, captured by channel steepness and its concavity

Science.gov (United States)

Vanacker, Veerle; von Blanckenburg, Friedhelm; Govers, Gerard; Molina, Armando; Campforts, Benjamin; Kubik, Peter W.

2015-01-01

Mountain rivers draining tropical regions are known to be great conveyor belts carrying efficiently more than half of the global sediment flux to the oceans. Many tropical mountain areas are located in tectonically active belts where the hillslope and stream channel morphology are rapidly evolving in response to changes in base level. Here, we report basin-wide denudation rates for an east-west transect through the tropical Andes. Hillslope and channel morphology vary systematically from east to west, reflecting the transition from high relief, strongly dissected topography in the escarpment zones into relatively low relief topography in the inter-Andean valley. The spatial pattern of differential denudation rates reflects the transient adjustment of the landscape to rapid river incision following tectonic uplift and river diversion. In the inter-Andean valley, upstream of the wave of incision, slopes and river channels display a relatively smooth, concave-up morphology and denudation rates (time scale of 104-105 a) are consistently low (3 to 200 mm/ka). In contrast, slopes and river channels of rejuvenated basins draining the eastern cordillera are steep to very steep; and the studied drainage basins show a wide range of denudation rate values (60 to 400 mm/ka) that increase systematically with increasing basin mean slope gradient, channel steepness, and channel convexity. Drainage basins that are characterised by strong convexities in their river longitudinal profiles systematically have higher denudation rates. As such, this is one of the first studies that provides field-based evidence of a correlation between channel concavity and basin mean denudation rates, consistent with process-based fluvial incision models.

Flow features that arise due to the interaction of a plane shock wave with concave profiles

CSIR Research Space (South Africa)

MacLucas, David A

2012-10-01

Full Text Available The focus of the author's thesis was the aerodynamic flow field that develops as a result of the interaction of a moving plane shock wave with concave profiles. In this presentation, he discusses some of the interesting flow phenomena that arise...

Experimental study of curvature effects on jet impingement heat transfer on concave surfaces

Directory of Open Access Journals (Sweden)

Ying Zhou

2017-04-01

Full Text Available Experimental study of the local and average heat transfer characteristics of a single round jet impinging on the concave surfaces was conducted in this work to gain in-depth knowledge of the curvature effects. The experiments were conducted by employing a piccolo tube with one single jet hole over a wide range of parameters: jet Reynolds number from 27000 to 130000, relative nozzle to surface distance from 3.3 to 30, and relative surface curvature from 0.005 to 0.030. Experimental results indicate that the surface curvature has opposite effects on heat transfer characteristics. On one hand, an increase of relative nozzle to surface distance (increasing jet diameter in fact enhances the average heat transfer around the surface for the same curved surface. On the other hand, the average Nusselt number decreases as relative nozzle to surface distance increases for a fixed jet diameter. Finally, experimental data-based correlations of the average Nusselt number over the curved surface were obtained with consideration of surface curvature effect. This work contributes to a better understanding of the curvature effects on heat transfer of a round jet impingement on concave surfaces, which is of high importance to the design of the aircraft anti-icing system.

TAF(II)170 interacts with the concave surface of TATA-binding protein to inhibit its DNA binding activity.

Science.gov (United States)

Pereira, L A; van der Knaap, J A; van den Boom, V; van den Heuvel, F A; Timmers, H T

2001-11-01

The human RNA polymerase II transcription factor B-TFIID consists of TATA-binding protein (TBP) and the TBP-associated factor (TAF) TAF(II)170 and can rapidly redistribute over promoter DNA. Here we report the identification of human TBP-binding regions in human TAF(II)170. We have defined the TBP interaction domain of TAF(II)170 within three amino-terminal regions: residues 2 to 137, 290 to 381, and 380 to 460. Each region contains a pair of Huntington-elongation-A subunit-Tor repeats and exhibits species-specific interactions with TBP family members. Remarkably, the altered-specificity TBP mutant (TBP(AS)) containing a triple mutation in the concave surface is defective for binding the TAF(II)170 amino-terminal region of residues 1 to 504. Furthermore, within this region the TAF(II)170 residues 290 to 381 can inhibit the interaction between Drosophila TAF(II)230 (residues 2 to 81) and TBP through competition for the concave surface of TBP. Biochemical analyses of TBP binding to the TATA box indicated that TAF(II)170 region 290-381 inhibits TBP-DNA complex formation. Importantly, the TBP(AS) mutant is less sensitive to TAF(II)170 inhibition. Collectively, our results support a mechanism in which TAF(II)170 induces high-mobility DNA binding by TBP through reversible interactions with its concave DNA binding surface.

Double concave cesium encapsulation by two charged sumanenyl bowls

Energy Technology Data Exchange (ETDEWEB)

Spisak, Sarah N.; Wei, Zheng; Petrukhina, Marina A. [Department of Chemistry, University at Albany, State University of New York, Albany, NY (United States); Rogachev, Andrey Yu. [Department of Chemistry, Illinois Institute of Technology, Chicago, IL (United States); Amaya, Toru [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita (Japan); Hirao, Toshikazu [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita (Japan); The Institute of Scientific and Industrial Research, Osaka University (Japan)

2017-03-01

The controlled reaction of Na and Cs, two alkali metals of different ionic sizes and binding abilities, with sumanene (C{sub 21}H{sub 12}) affords a novel type of organometallic sandwich [Cs(C{sub 21}H{sub 11}{sup -}){sub 2}]{sup -}, which crystallized as a solvent-separated ion pair with a [Na(18-crown-6)(THF){sub 2}]{sup +} cation (where THF=tetrahydrofuran). The unprecedented double concave encapsulation of a metal ion by two bowl-shaped sumanenyl anions in [Cs(C{sub 21}H{sub 11}{sup -}){sub 2}]{sup -} was revealed crystallographically. Evaluation of bonding and energetics of the remarkable product was accomplished computationally (B2PLYP-D/TZVP/ZORA), providing insights into its formation. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Feedback-Capacity of Degraded Gaussian Vector BC using Directed Information and Concave Envelopes

OpenAIRE

Ramachandran, Viswanathan

2017-01-01

It is known that the capacity region of a two user physically degraded discrete memoryless (DM) broadcastchannel (BC) is not enlarged by feedback. An identical result holds true for a physically degraded Gaussian BC,established later using a variant of the Entropy Power Inequality (EPI). In this paper, we extend the latter resultto a physically degraded Gaussian Vector BC (PD-GVBC). However, the extension is not EPI based, but employs arecent result on the factorization of concave envelopes. ...

Plasmonic enhancement of UV emission from ZnO thin films induced by Al nano-concave arrays

International Nuclear Information System (INIS)

Norek, Małgorzata; Łuka, Grzegorz; Włodarski, Maksymilian

2016-01-01

Highlights: • Al nano-concave arrays with different interpore distance (D c ) were prepared. • PL of ZnO thin films deposited directly on the Al nano-concaves were studied. • The effect of 10 nm Al 2 O 3 spacer on PL emission from ZnO thin films was analyzed. • Plasmonic enhancement of the PL emission was dependent on the D c and the spacer. • The highest 9-fold enhancement was obtained for the Al/ZnO sample with D c ∼333 nm. - Abstract: Surface plasmons (SPs) supported by Al nano-concave arrays with increasing interpore distance (D c ) were used to enhance the ultraviolet light emission from ZnO thin films. Two sets of samples were prepared: in the first set the thin ZnO films were deposited directly on Al nanoconcaves (the Al/ZnO samples) and in the second set a 10 nm − Al 2 O 3 spacer was placed between the textured Al and the ZnO films (the Al/Al 2 O 3 -ALD/ZnO samples). In the Al/ZnO samples the enhancement was limited by a nonradiative energy dissipation due to the Ohmic loss in the Al metal. However, for the ZnO layer deposited directly on Al nanopits synthesized at 150 V (D c = 333 ± 18 nm), the largest 9-fold enhancement was obtained by achieving the best energy fit between the near band-edge (NBE) emission from ZnO and the λ (0,1) SPP resonance mode. In the Al/Al 2 O 3 -ALD/ZnO samples the amplification of the UV emission was smaller than in the Al/ZnO samples due to a big energy mismatch between the NBE emission and the λ (0,1) plasmonic mode. The results obtained in this work indicate that better tuning of the NBE − λ (0,1) SPP resonance mode coupling is possible through a proper modification of geometrical parameters in the Al/Al 2 O 3 -ALD/ZnO system such as Al nano-concave spacing and the thickness of the corresponding layer. This approach will reduce the negative influence of the non-radiative plasmonic modes and most likely will lead to further enhancement of the SP-modulated UV emission from ZnO thin films.

Plasmonic enhancement of UV emission from ZnO thin films induced by Al nano-concave arrays

Energy Technology Data Exchange (ETDEWEB)

Norek, Małgorzata, E-mail: mnorek@wat.edu.pl [Department of Advanced Materials and Technologies, Faculty of Advanced Technologies and Chemistry, Military University of Technology, Kaliskiego 2, 00-908 Warsaw (Poland); Łuka, Grzegorz [Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw (Poland); Włodarski, Maksymilian [Institute of Optoelectronics, Military University of Technology, Str. Kaliskiego 2, 00-908 Warszawa (Poland)

2016-10-30

Highlights: • Al nano-concave arrays with different interpore distance (D{sub c}) were prepared. • PL of ZnO thin films deposited directly on the Al nano-concaves were studied. • The effect of 10 nm Al{sub 2}O{sub 3} spacer on PL emission from ZnO thin films was analyzed. • Plasmonic enhancement of the PL emission was dependent on the D{sub c} and the spacer. • The highest 9-fold enhancement was obtained for the Al/ZnO sample with D{sub c} ∼333 nm. - Abstract: Surface plasmons (SPs) supported by Al nano-concave arrays with increasing interpore distance (D{sub c}) were used to enhance the ultraviolet light emission from ZnO thin films. Two sets of samples were prepared: in the first set the thin ZnO films were deposited directly on Al nanoconcaves (the Al/ZnO samples) and in the second set a 10 nm − Al{sub 2}O{sub 3} spacer was placed between the textured Al and the ZnO films (the Al/Al{sub 2}O{sub 3}-ALD/ZnO samples). In the Al/ZnO samples the enhancement was limited by a nonradiative energy dissipation due to the Ohmic loss in the Al metal. However, for the ZnO layer deposited directly on Al nanopits synthesized at 150 V (D{sub c} = 333 ± 18 nm), the largest 9-fold enhancement was obtained by achieving the best energy fit between the near band-edge (NBE) emission from ZnO and the λ{sub (0,1)} SPP resonance mode. In the Al/Al{sub 2}O{sub 3}-ALD/ZnO samples the amplification of the UV emission was smaller than in the Al/ZnO samples due to a big energy mismatch between the NBE emission and the λ{sub (0,1)} plasmonic mode. The results obtained in this work indicate that better tuning of the NBE − λ{sub (0,1)} SPP resonance mode coupling is possible through a proper modification of geometrical parameters in the Al/Al{sub 2}O{sub 3}-ALD/ZnO system such as Al nano-concave spacing and the thickness of the corresponding layer. This approach will reduce the negative influence of the non-radiative plasmonic modes and most likely will lead to further

The improvement of GaN-based LED grown on concave nano-pattern sapphire substrate with SiO2 blocking layer

International Nuclear Information System (INIS)

Lin, Jyun-Hao; Huang, Shyh-Jer; Su, Yan-Kuin; Huang, Kai-Wen

2015-01-01

Highlights: • Concave nano-patterned sapphire substrates with SiO 2 blocking layer. • The IQE is almost two times larger than that of conventional one. • The EQE was extremely enhanced more than 100%. - Abstract: In contrast to convex nano-pattern sapphire substrates (NPSS), which are frequently used to fabricate high-quality nitride-based light-emitting diodes (LEDs), concave NPSS have been paid relatively less attention. In this study, a concave NPSS was fabricated, and its nitride epitaxial growth process was evaluated in a step by step manner. A SiO 2 layer was used to avoid nucleation over the sidewall and bottom of the nano-patterns to reduce dislocation reformation. Traditional LED structures were grown on the NPSS layer to determine its influence on device performance. X-ray diffraction, etched pit density, inverse leakage current, and internal quantum efficiency (IQE) results showed that dislocations and non-radiative recombination centers are reduced by the NPSS constructed with a SiO 2 blocking layer. An IQE twice that on a planar substrate was also achieved; such a high IQE significantly enhanced the external quantum efficiency of the resultant device. Taken together, the results demonstrate that the SiO 2 blocking layer proposed in this work can enhance the performance of LEDs.

Hydrogen storage in pure and Li-doped carbon nanopores: combined effects of concavity and doping.

Science.gov (United States)

Cabria, I; López, M J; Alonso, J A

2008-04-14

Density functional calculations are reported for the adsorption of molecular hydrogen on carbon nanopores. Two models for the pores have been considered: (i) The inner walls of (7,7) carbon nanotubes and (ii) the highly curved inner surface of nanotubes capped on one end. The effect of Li doping is investigated in all cases. The hydrogen physisorption energies increase due to the concavity effect inside the clean nanotubes and on the bottom of the capped nanotubes. Li doping also enhances the physisorption energies. The sum of those two effects leads to an increase by a factor of almost 3 with respect to the physisorption in the outer wall of undoped nanotubes and in flat graphene. Application of a quantum-thermodynamical model to clean cylindrical pores of diameter 9.5 A, the diameter of the (7,7) tube, indicates that cylindrical pores of this size can store enough hydrogen to reach the volumetric and gravimetric goals of the Department of Energy at 77 K and low pressures, although not at 300 K. The results are useful to explain the experiments on porous carbons. Optimizations of the pore size, concavity, and doping appear as promising alternatives for achieving the goals at room temperature.

A new signal restoration method based on deconvolution of the Point Spread Function (PSF) for the Flat-Field Holographic Concave Grating UV spectrometer system

Science.gov (United States)

Dai, Honglin; Luo, Yongdao

2013-12-01

In recent years, with the development of the Flat-Field Holographic Concave Grating, they are adopted by all kinds of UV spectrometers. By means of single optical surface, the Flat-Field Holographic Concave Grating can implement dispersion and imaging that make the UV spectrometer system design quite compact. However, the calibration of the Flat-Field Holographic Concave Grating is very difficult. Various factors make its imaging quality difficult to be guaranteed. So we have to process the spectrum signal with signal restoration before using it. Guiding by the theory of signals and systems, and after a series of experiments, we found that our UV spectrometer system is a Linear Space- Variant System. It means that we have to measure PSF of every pixel of the system which contains thousands of pixels. Obviously, that's a large amount of calculation .For dealing with this problem, we proposes a novel signal restoration method. This method divides the system into several Linear Space-Invariant subsystems and then makes signal restoration with PSFs. Our experiments turn out that this method is effective and inexpensive.

Revisiting maximum-a-posteriori estimation in log-concave models: from differential geometry to decision theory

OpenAIRE

Pereyra, Marcelo

2016-01-01

Maximum-a-posteriori (MAP) estimation is the main Bayesian estimation methodology in many areas of data science such as mathematical imaging and machine learning, where high dimensionality is addressed by using models that are log-concave and whose posterior mode can be computed efficiently by using convex optimisation algorithms. However, despite its success and rapid adoption, MAP estimation is not theoretically well understood yet, and the prevalent view is that it is generally not proper ...

Automatic choroid cells segmentation and counting based on approximate convexity and concavity of chain code in fluorescence microscopic image

Science.gov (United States)

Lu, Weihua; Chen, Xinjian; Zhu, Weifang; Yang, Lei; Cao, Zhaoyuan; Chen, Haoyu

2015-03-01

In this paper, we proposed a method based on the Freeman chain code to segment and count rhesus choroid-retinal vascular endothelial cells (RF/6A) automatically for fluorescence microscopy images. The proposed method consists of four main steps. First, a threshold filter and morphological transform were applied to reduce the noise. Second, the boundary information was used to generate the Freeman chain codes. Third, the concave points were found based on the relationship between the difference of the chain code and the curvature. Finally, cells segmentation and counting were completed based on the characteristics of the number of the concave points, the area and shape of the cells. The proposed method was tested on 100 fluorescence microscopic cell images, and the average true positive rate (TPR) is 98.13% and the average false positive rate (FPR) is 4.47%, respectively. The preliminary results showed the feasibility and efficiency of the proposed method.

Electron optical characteristics of a concave electrostatic electron mirror for a scanning electron microscope

International Nuclear Information System (INIS)

Hamarat, R.T.; Witzani, J.; Hoerl, E.M.

1984-08-01

Numerical computer calculations are used to explore the design characteristics of a concave electrostatic electron mirror for a mirror attachment for a conventional scanning electron microscope or an instrument designed totally as a scanning electron mirror microscope. The electron paths of a number of set-ups are calculated and drawn graphically in order to find the optimum shape and dimensions of the mirror geometry. This optimum configuration turns out to be the transition configuration between two cases of electron path deflection, towards the optical axis of the system and away from it. (Author)

Inference from concave stochastic frontiers and the covariance of firm efficiency measures across firms

International Nuclear Information System (INIS)

Dashti, Imad

2003-01-01

This paper uses a Bayesian stochastic frontier model to obtain confidence intervals on firm efficiency measures of electric utilities rather than the point estimates reported in most previous studies. Results reveal that the stochastic frontier model yields imprecise measures of firm efficiency. However, the application produces much more precise inference on pairwise efficiency comparisons of firms due to a sometimes strong positive covariance of efficiency measures across firms. In addition, we examine the sensitivity to functional form by repeating the analysis for Cobb-Douglas, translog and Fourier frontiers, with and without imposing monotonicity and concavity

How safe is safe?

International Nuclear Information System (INIS)

Hughes, C.F.; Flood, M.

1996-01-01

60 and 70 degree convexo-concave valve. Nine hundred and one valves were implanted in Australia. Twelve strut fractures were reported. Two other patients have been explanted and have demonstrated 'single leg separation'. This particular problem was only investigated when two patients died of a fractured valve in the same hospital on the same day. A retrospective study of all known patients in Australia has shown poor follow up, lack of knowledge and indeed lack of interest in device failure modes. Consequently, the Australian and New Zealand Heart Valve Registry was established to track all implanted valves and to notify physicians of any new information. This is perhaps the first device-specific register in Australia. The safety of individual devices is often not known by manufacturers, regulators and clinicians alike. No follow up is available and large volume long term studies are yet to be implemented for the majority of devices. Without such studies and without mandatory problem reporting, the relative safety of medical devices will continue to be measured by banner headlines, sensational TV 'grabs' and protracted law suits. At present, only schemes such as the Problem Reporting Scheme can tell us (albeit vaguely) 'how safe is safe'

Reliable single chip genotyping with semi-parametric log-concave mixtures.

Directory of Open Access Journals (Sweden)

Ralph C A Rippe

Full Text Available The common approach to SNP genotyping is to use (model-based clustering per individual SNP, on a set of arrays. Genotyping all SNPs on a single array is much more attractive, in terms of flexibility, stability and applicability, when developing new chips. A new semi-parametric method, named SCALA, is proposed. It is based on a mixture model using semi-parametric log-concave densities. Instead of using the raw data, the mixture is fitted on a two-dimensional histogram, thereby making computation time almost independent of the number of SNPs. Furthermore, the algorithm is effective in low-MAF situations.Comparisons between SCALA and CRLMM on HapMap genotypes show very reliable calling of single arrays. Some heterozygous genotypes from HapMap are called homozygous by SCALA and to lesser extent by CRLMM too. Furthermore, HapMap's NoCalls (NN could be genotyped by SCALA, mostly with high probability. The software is available as R scripts from the website www.math.leidenuniv.nl/~rrippe.

Facile synthesis and electrochemiluminescence application of concave trisoctahedral Pd@Au core-shell nanocrystals bound by {331} high-index facets.

Science.gov (United States)

Zhang, Ling; Niu, Wenxin; Li, Zhiyuan; Xu, Guobao

2011-10-07

Concave trisoctahedral (TOH) Pd@Au core-shell nanocrystals bound by {331} facets have been synthesized for the first time. Pd nanocubes and cetyltrimethylammonium chloride were used as the structure-directing cores and capping agents, respectively. Their optical and electrocatalytic properties were investigated. This journal is © The Royal Society of Chemistry 2011

Thermal-hydraulic performance of a multiple jet cooling module with a concave dimple array in a helium-cooled divertor

Energy Technology Data Exchange (ETDEWEB)

Jung, Hyo-Yeon; Kim, Kwang-Yong, E-mail: kykim@inha.ac.kr

2017-01-15

A numerical study was performed to evaluate the thermal-hydraulic performance of a finger type cooling module, where multiple jets impinge on the surface with concave dimples, in the divertor of a nuclear fusion reactor. Conjugate heat transfer was analyzed in both the solid and fluid domains using three-dimensional Reynolds-averaged Navier-Stokes equations with the shear stress transport turbulence model. The computational domain consisted of a single fluid domain and three solid domains: tile, thimble, and cartridge. The numerical results for the temperature variation on the tile were validated in comparison with the experimental data. A parametric study was performed with two design variables, the ratios of dimple diameter and dimple height to the nozzle diameter, and two dimple arrays (inline and staggered arrays). The parametric study showed that the heat transfer rate was increased by up to 2.62% by introducing concave dimples, and that the heat transfer and pressure drop performances increased with increasing diameter and height of the dimples for a specified dimple array.

Re-operation for aortic and mitral prosthetic dysfunctions.

Science.gov (United States)

Kaul, T K; Sastry, M R; Mercer, J L; Meade, J B

1985-01-01

The overall incidence of re-operation and prosthetic valve endocarditis was low in the present series as mechanical prostheses were used predominantly. The prosthetic dysfunctions were less frequent following the primary implantation with Bjork Shiley prostheses, but high operative risk was associated with the clotted Bjork Shiley prostheses. We also had unusual experience of strut fracture and sticking of Bjork Shiley discs in the closed position in both aortic and mitral positions. The early deaths were nil since the use of cardioplegic protection. Intra-operative bleeding due to adhesions can be minimised by using synthetic or heterologous pericardium during the primary operation.

Fabrication of complex free-standing nanostructures with concave and convex curvature via the layer-by-layer approach.

Science.gov (United States)

Raoufi, Mohammad; Schönherr, Holger

2014-02-18

We report on the fabrication of unprecedented free-standing complex polymeric nanoobjects, which possess both concave and convex curvatures, by exploiting the layer-by-layer (LBL) deposition of polyelectrolytes. In a combined top-down/bottom-up replication approach pore diameter-modulated anodic aluminum oxide (AAO) templates, fabricated by temperature modulation hard anodization (TMHA), were replicated with multilayers of poly(styrene sulfonate) (PSS) and poly(allylamine hydrochloride) (PAH) to yield open nanotubes with diameters in the wide and narrow segments of 210 and 150 nm, respectively. To obtain stable pore diameter-modulated nanopores, which possess segment lengths between 1 and 5 μm and 5 and 10 μm in the narrow and wide pore portion, respectively, conventional hard anodization of aluminum was followed by a subsequent temperature-modulated anodization. After removing the backside aluminum electrode, silanizing the aluminum oxide, and passivating the exposed membrane surface with a thin layer of gold, PSS and PAH were deposited alternatingly to yield LBL multilayers. For optimized LBL multilayer thicknesses and compactness, established in separate experiments on silicon substrates and nanoporous AAO with straight pores, free-standing polymeric nanoobjects with concave and convex curvatures, were obtained. These were stable for wall thickness to pore diameter ratios of ≥0.08.

Longitudinal study of iris concavity, corneal biomechanics, and correlations to ocular biometry in a cohort of 10- to 12-year-old UK schoolboys: 2-year follow-up data.

Science.gov (United States)

Shah, Ameet; Lascaratos, Gerassimos; Garway-Heath, David F; Foster, Paul J; Barton, Keith

2014-06-10

To explore changes in iris curvature over a 2-year period. To investigate associations between iris curvature and ocular biometric parameters. To explore relationships between a number of nonocular measurements and ocular biometric parameters. Schoolboys enrolled 2 years previously were invited to return for anterior segment optical coherence tomography, corneal hysteresis (CH), corneal resistance factor (CRF), and axial biometric measurements. Refractive error was assessed and measures of height, weight, waist circumference, digit ratio, and percentage body fat taken. Mean spherical equivalent refraction reduced by 0.76 diopters and mean iris concavity, defined as a measurement of less than or equal to -0.1 mm, increased by 0.018 mm at distance fixation and 0.04 mm on accommodation. Compared with 2 years previously, the prevalence of iris concavity increased from 24% to 32% on distance fixation and from 65% to 84% on accommodation. Variables significantly associated with nonaccommodating iris curvature were anterior chamber depth (ACD, P = 0.029) and mean scleral spur angle (P = 0.0001). Variables significantly associated with accommodating iris curvature were ACD (P = 0.02), lens vault (P = 0.047), and scleral spur angle (P Iris concavity was more prevalent in this cohort of schoolboys than 2 years earlier. The degree of concavity remains related to ACD and lens vault. The association between spur-to-spur distance and CH was similar at baseline and after 2 years. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Three-dimensional imaging of a complex concaved cuboctahedron copper sulfide crystal by x-ray nanotomography

International Nuclear Information System (INIS)

Chen Jie; Tian Jinping; Li Wenjie; Tian Yangchao; Wu Chunyan; Yu Shuhong

2008-01-01

By combining Fresnel zone-plate based transmission x-ray microscopy with computed tomography, the nanoscale features in materials with complex shapes can be imaged using synchrotron radiation. The tomographic data sets of a complex copper sulfide crystal were acquired in the angle range ±70 deg. at photon energy of 8.0 keV and then were reconstructed by a standard filtered-back-projection algorithm. This experiment shows the quantifiable three-dimensional information of the copper sulfide crystal, which offers a complete understanding of the concaved cuboctahedron structure with 14 faces comprising of six squares and eight triangles

Designs of contraction nozzle and concave back-wall for IFMIF target

Energy Technology Data Exchange (ETDEWEB)

Ida, Mizuho E-mail: ida@ifmif.tokai.jaeri.go.jp; Nakamura, Hideo; Nakamura, Hiroo; Takeuchi, Hiroshi

2004-02-01

For the liquid lithium flow target of International Fusion Materials Irradiation Facility (IFMIF), the double reducer (two-step contraction) nozzle with a high-contraction ratio of 10 which generated high-speed uniform jet flows up to 20 m/s was proposed. Multi-dimensional hydraulic analyses were carried out to verify the performance of the proposed nozzle. The analytical results showed that the double reducer nozzle would well generate high-speed uniform flow, while one-step contraction nozzle generated non-uniform flow and resulted in flow thickening at the beam footprint. For the target design, the range of the concave back-wall radius with no lithium boiling due to the centrifugal force and proper component arrangement in the irradiation test cell was determined by the thermal-hydraulic analysis of a free-surface flow. It was verified that the back-wall radius from 0.25 to 10 m was acceptable in the velocity range of 10-20 m/s.

Designs of contraction nozzle and concave back-wall for IFMIF target

International Nuclear Information System (INIS)

Ida, Mizuho; Nakamura, Hideo; Nakamura, Hiroo; Takeuchi, Hiroshi

2004-01-01

For the liquid lithium flow target of International Fusion Materials Irradiation Facility (IFMIF), the double reducer (two-step contraction) nozzle with a high-contraction ratio of 10 which generated high-speed uniform jet flows up to 20 m/s was proposed. Multi-dimensional hydraulic analyses were carried out to verify the performance of the proposed nozzle. The analytical results showed that the double reducer nozzle would well generate high-speed uniform flow, while one-step contraction nozzle generated non-uniform flow and resulted in flow thickening at the beam footprint. For the target design, the range of the concave back-wall radius with no lithium boiling due to the centrifugal force and proper component arrangement in the irradiation test cell was determined by the thermal-hydraulic analysis of a free-surface flow. It was verified that the back-wall radius from 0.25 to 10 m was acceptable in the velocity range of 10-20 m/s

Fabrication of agarose concave petridish for 3D-culture microarray method for spheroids formation of hepatic cells.

Science.gov (United States)

Zhang, Binbin; Li, Yang; Wang, Gaoshang; Jia, Zhidong; Li, Haiyan; Peng, Qing; Gao, Yi

2018-04-19

Liver is one of the most important organ in the body. But there are many limitations about liver transplantation for liver failure. It is quite important to develop the xenogeneic biological liver for providing an alternation to transplantation or liver regeneration. In this paper, we proposed a method to construct a novel kind of agarose 3D-culture concave microwell array for spheroids formation of hepatic cells. Using the 3D printing method, the microwell array was fabricated with an overall size of 6.4 mm × 6.4 mm, containing 121 microwells with 400 μm width/400 μm thickness. By exploiting the Polydimethylsiloxane (PDMS) membranes as a bridge, we finally fabricated the agarose one. We co-cultured three types of liver cells with bionics design in the microwell arrays. Using the methods described above, the resulting co-formed hepatocyte spheroids maintained the high viability and stable liver-specific functions. This engineered agarose concave microwell array could be a potentially useful tool for forming the elements for biological liver support. After developing the complete system, we also would consider to scale up the application of this system. It will be not only applied to the therapy of human organ damage, but also to the development of disease models and drug screening models.

Studies on the zeros of Bessel functions and methods for their computation: 2. Monotonicity, convexity, concavity, and other properties

Science.gov (United States)

Kerimov, M. K.

2016-07-01

This work continues the study of real zeros of first- and second-kind Bessel functions and Bessel general functions with real variables and orders begun in the first part of this paper (see M.K. Kerimov, Comput. Math. Math. Phys. 54 (9), 1337-1388 (2014)). Some new results concerning such zeros are described and analyzed. Special attention is given to the monotonicity, convexity, and concavity of zeros with respect to their ranks and other parameters.

太阳能技术在“绿色凹宅”中的应用%Application of Solar Energy Technology in Green Concave House

Institute of Scientific and Technical Information of China (English)

莫理莉

2014-01-01

This paper introduced the application of solar energy technology in green concave house.The grid-connection photovoltaic power generation was used,which sent the redundant power back to the power network.The photovoltaic solar-thermal integrated solar panels provided the output of electricity and daily at the same time.The smart home system provided the comfortable environment for green concave house.The green concave house is a successful and low energy consumption example,which could provide references for the area of abundant solar energy and dispersal residence.%介绍了太阳能技术在“绿色凹宅”中的应用。采用的并网型太阳能光伏发电系统，当有余电时可回馈电网。铺设的光伏光热一体化太阳能板，在电力输出的同时提供生活热水。智能家居系统给“绿色凹宅”提供舒适的环境。“绿色凹宅”是一个比较成功的环保、低能耗的住宅实例，对太阳能资源丰富而又居住分散的地区有很好的借鉴意义。

Evaluation of concave dose distributions created using an inverse planning system

International Nuclear Information System (INIS)

Hunt, Margie A.; Hsiung, C.-Y.; Spirou, Spirodon V.; Chui, C.-S.; Amols, Howard I.; Ling, Clifton C.

2002-01-01

Purpose: To evaluate and develop optimum inverse treatment planning strategies for the treatment of concave targets adjacent to normal tissue structures. Methods and Materials: Optimized dose distributions were designed using an idealized geometry consisting of a cylindrical phantom with a concave kidney-shaped target (PTV) and cylindrical normal tissues (NT) placed 5-13 mm from the target. Targets with radii of curvature from 1 to 2.75 cm were paired with normal tissues with radii between 0.5 and 2.25 cm. The target was constrained to a prescription dose of 100% and minimum and maximum doses of 95% and 105% with relative penalties of 25. Maximum dose constraint parameters for the NT varied from 10% to 70% with penalties from 10 to 1000. Plans were evaluated using the PTV uniformity index (PTV D max /PTV D 95 ) and maximum normal tissue doses (NT D max /PTV D 95 ). Results: In nearly all situations, the achievable PTV uniformity index and the maximum NT dose exceeded the corresponding constraints. This was particularly true for small PTV-NT separations (5-8 mm) or strict NT dose constraints (10%-30%), where the achievable doses differed from the requested by 30% or more. The same constraint parameters applied to different PTV-NT separations yielded different dose distributions. For most geometries, a range of constraints could be identified that would lead to acceptable plans. The optimization results were fairly independent of beam energy and radius of curvature, but improved as the number of beams increased, particularly for small PTV-NT separations or strict dose constraints. Conclusion: Optimized dose distributions are strongly affected by both the constraint parameters and target-normal tissue geometry. Standard site-specific constraint templates can serve as a starting point for optimization, but the final constraints must be determined iteratively for individual patients. A strategy whereby NT constraints and penalties are modified until the highest

A new laryngeal mask supraglottic airway device with integrated balloon line: a descriptive and comparative bench study

Directory of Open Access Journals (Sweden)

Zhou YH

2016-11-01

Full Text Available YingHai Zhou,1 Korinne Jew2 1Research & Development, Patient Monitoring & Recovery, Medtronic Technology Center, Shanghai, People’s Republic of China; 2Medical Affairs, Minimally Invasive Therapies Group, Medtronic, Boulder, CO, USA Abstract: Laryngeal masks are invasive devices for airway management placed in the supraglottic position. The Shiley™ laryngeal mask (Shiley™ LM features an integrated inflation tube and airway shaft to facilitate product insertion and reduce the chance of tube occlusion when patients bite down. This study compared the Shiley LM to two other disposable laryngeal mask devices, the Ambu® AuraStraight™ and the LMA Unique™. Overall device design, tensile strength, flexibility of various structures, and sealing performance were measured. The Shiley LM is structurally stronger and its shaft is more resistant to compression than the other devices. The Shiley LM is generally less flexible than the other devices, but this relationship varies with device size. Sealing performance of the devices was similar in a bench assay. The results of this bench study demonstrate that the new Shiley LM resembles other commercially available laryngeal mask devices, though it exhibits greater tensile strength and lower flexibility. Keywords: laryngeal mask, supraglottic airway, supralaryngeal device

Fabricating small-scale, curved, polymeric structures with convex and concave menisci through interfacial free energy equilibrium.

Science.gov (United States)

Cheng, Chao-Min; Matsuura, Koji; Wang, I-Jan; Kuroda, Yuka; LeDuc, Philip R; Naruse, Keiji

2009-11-21

Polymeric curved structures are widely used in imaging systems including optical fibers and microfluidic channels. Here, we demonstrate that small-scale, poly(dimethylsiloxane) (PDMS)-based, curved structures can be fabricated through controlling interfacial free energy equilibrium. Resultant structures have a smooth, symmetric, curved surface, and may be convex or concave in form based on surface tension balance. Their curvatures are controlled by surface characteristics (i.e., hydrophobicity and hydrophilicity) of the molds and semi-liquid PDMS. In addition, these structures are shown to be biocompatible for cell culture. Our system provides a simple, efficient and economical method for generating integrateable optical components without costly fabrication facilities.

Self-centring technique for fibre optic microlens mounting using a concave cone-etched fibre

International Nuclear Information System (INIS)

Demagh, Nacer-Eddine; Guessoum, Assia; Zegari, Rabah; Gharbi, Tijani

2011-01-01

Several techniques of centring a microlens onto the fibre optic end face are studied. In most of them, microsphere lenses are centred with the aid of high-accuracy micro-positioners. This process is complicated with regard to the difficulty in manipulating microsphere lenses. In this paper, a simple and accurate self-centring method for mounting microsphere lenses using a concave cone etched fibre (Demagh et al 2006 Meas. Sci. Technol. 17 119–22) is described. This technique allows the centring of a wide variety of microlens radii, typically 7 µm to over 24 µm. The proposed process, however, is not affected by any spatial positioning control of microspheres. In over 85% of the attempts, the microsphere lenses were centred on the fibre axis to within 0.12 µm

Posterior all-pedicle screw instrumentation combined with multiple chevron and concave rib osteotomies in the treatment of adolescent congenital kyphoscoliosis.

Science.gov (United States)

Ayvaz, Mehmet; Olgun, Z Deniz; Demirkiran, H Gokhan; Alanay, Ahmet; Yazici, Muharrem

2014-01-01

Congenital kyphoscoliosis is a disorder that often requires surgical treatment. Although many methods of surgical treatment exist, posterior-only vertebral column resection with instrumentation and fusion seem to have become the gold standard for very severe and very rigid curves. Multiple chevron and concave rib osteotomies have been previously reported to be effective in the treatment of neglected severe idiopathic curves. We hypothesized that this method may also be used successfully in the treatment of congenital kyphoscoliosis. To evaluate the effectiveness and safety of multiple chevron osteotomies combined with concave rib osteotomy and posterior pedicle screw instrumentation. Retrospective chart review in the spine service of a large university hospital. Adolescent patients undergoing a specific surgical treatment for the indication of rigid congenital kyphoscoliotic deformity. Radiographic images were used for the measurement of deformity correction. The Turkish version of the Scoliosis Research Society 22 (SRS-22) Patient Questionnaire has been used as a clinical outcome measure in the patient population. A retrospective chart review was performed. Patients admitted to Hacettepe Hospital Spine Center during the period of 2005 to 2009 were included. Criteria for inclusion were as follows: adolescent age group (10-16 years); congenital kyphoscoliosis; formation and/or segmentation defect of at least two vertebral motion segments; surgical treatment of deformity by posterior all-pedicle screw instrumentation, multiple chevron osteotomies, and multiple concave rib osteotomies; follow-up of at least 24 months; and a complete set of preoperative, postoperative, and follow-up standing posteroanterior and lateral full spinal radiographs. The patients' hospital records and X-rays were reviewed. Duration of surgery, intraoperative blood loss, postoperative transfusion requirements, postoperative stay in postanesthesia care unit (PACU), time of hospitalization, and

Self-Similar Solutions of Rényi’s Entropy and the Concavity of Its Entropy Power

Directory of Open Access Journals (Sweden)

Agapitos N. Hatzinikitas

2015-08-01

Full Text Available We study the class of self-similar probability density functions with finite mean and variance, which maximize Rényi’s entropy. The investigation is restricted in the Schwartz space S(Rd and in the space of l-differentiable compactly supported functions Clc (Rd. Interestingly, the solutions of this optimization problem do not coincide with the solutions of the usual porous medium equation with a Dirac point source, as occurs in the optimization of Shannon’s entropy. We also study the concavity of the entropy power in Rd with respect to time using two different methods. The first one takes advantage of the solutions determined earlier, while the second one is based on a setting that could be used for Riemannian manifolds.

A theoretical model for flow boiling CHF from short concave heaters

International Nuclear Information System (INIS)

Galloway, J.E.; Mudawar, I.

1995-01-01

Experiments were performed to enable the development of a new theoretical mode for the enhancement in CHF commonly observed with flow boiling on concave heater as compared to straight heaters. High-speed video imaging and photomicrography were employed to capture the trigger mechanism for CHF each type heater. A wavy vapor layer was observed to engulf the heater surface in each case, permitting liquid access to the surface only in regions where depressions (troughs) in the liquid vapor interface made contact with the surface. CHF in each case occurred when the pressure force exerted upon the wavy vapor-liquid inter ace in the contact region could no longer overcome the momentum of the vapor produced in these regional. Shorter interfacial wavelengths with greater curvature were measured on the curve, heater than on the straight heater, promoting a greater pressure force on the wave interface and a corresponding increase in CHF for the curved heater. A theoretics. CHF model is developed from these observations, based upon a new theory for hydrodynamic instability, along a curved interface. CHF data are predicted with good accuracy for both heaters. 23 refs., 9 figs

Reconstruction and Visualization of Fiber and Laminar Structure in the Normal Human Heart from Ex Vivo DTMRI Data

International Nuclear Information System (INIS)

Rohmer, Damien; Sitek, Arkadiusz; Gullberg, Grant T.

2006-01-01

Background--The human heart is composed of a helical network of muscle fibers. These fibers are organized to form sheets that are separated by cleavage surfaces. This complex structure of fibers and sheets is responsible for the orthotropic mechanical properties of cardiac muscle. The understanding of the configuration of the 3D fiber and sheet structure is important for modeling the mechanical and electrical properties of the heart and changes in this configuration maybe of significant importance to understand the remodeling after myocardial infarction. Methods--Anisotropic least square filtering followed by fiber and sheet tracking techniques were applied to Diffusion Tensor Magnetic Resonance Imaging (DTMRI) data of the excised human heart. The fiber configuration was visualized by using thin tubes to increase 3-dimensional visual perception of the complex structure. The sheet structures were reconstructed from the DTMRI data, obtaining surfaces that span the wall from the endo- to the epicardium. All visualizations were performed using the high-quality ray-tracing software POV-Ray. Results--The fibers are shown to lie in sheets that have concave or convex transmural structure which correspond to histological studies published in the literature. The fiber angles varied depending on the position between the epi- and endocardium. The sheets had a complex structure that depended on the location within the myocardium. In the apex region the sheets had more curvature. Conclusions--A high-quality visualization algorithm applied to demonstrated high quality DTMRI data is able to elicit the comprehension of the complex 3 dimensional structure of the fibers and sheets in the heart

Role of vortices in cavitation formation in the flow across a mechanical heart valve.

Science.gov (United States)

Li, Chi-Pei; Lu, Po-Chien; Liu, Jia-Shing; Lo, Chi-Wen; Hwang, Ned H

2008-07-01

Cavitation occurs during mechanical heart valve closure when the local pressure drops below vapor pressure. The formation of stable gas bubbles may result in gaseous emboli, and secondarily cause transient ischemic attacks or strokes. It is noted that instantaneous valve closure, occluder rebound and high-speed leakage flow generate vortices that promote low-pressure regions in favor of stable bubble formation; however, to date no studies have been conducted for the quantitative measurement and analysis of these vortices. A Björk-Shiley Monostrut (BSM) monoleaflet valve was placed in the mitral position of a pulsatile mock circulatory loop. Particle image velocimetry (PIV) and pico coulomb (PCB) pressure measurements were applied. Flow field measurements were carried out at t = -5, -3, -1, -0.5, 0 (valve closure), 0.3, 0.5, 0.75, 1.19, 1.44, 1.69, 1.94, 2, 2.19, 2.54, 2.79, 3.04, 3.29, 3.54, 5 and 10 ms. The vortices were quantitatively analyzed using the Rankine vortex model. A single counter-clockwise vortex was The instantaneous formation of cavitation bubbles at mechanical heart valve (MHV) closure, which subsequently damage blood cells and valve integrity, is a well-known and widely studied phenomenon (1-4). Contributing factors seem to include the water-hammer, squeeze flow and Venturi effects, all of which are short-lived. Both, Dauzat et al. (5) and Sliwka et al. (6) have detected high-intensity transient signals (HITS) with transcranial Doppler ultrasound in the carotid and cerebral arteries of MHV recipients, while Deklunder (7) observed clinical occurrences of cerebral gas emboli that were not seen with bioprosthetic valves. These detected over the major orifice, while a pair of counter-rotating vortices was found over the minor orifice. Velocity profiles were consistent with Rankine vortices. The vortex strength and magnitude of the pressure drop peaked shortly after initial occluder-housing impact and rapidly decreased after 0.5 ms, indicating viscous

Etude aerodynamique d'un jet turbulent impactant une paroi concave

Science.gov (United States)

LeBlanc, Benoit

Etant donne la demande croissante de temperatures elevees dans des chambres de combustion de systemes de propulsions en aerospatiale (turbomoteurs, moteur a reaction, etc.), l'interet dans le refroidissement par jets impactant s'est vu croitre. Le refroidissement des aubes de turbine permet une augmentation de temperature de combustion, ce qui se traduit en une augmentation de l'efficacite de combustion et donc une meilleure economie de carburant. Le transfert de chaleur dans les au bages est influence par les aspects aerodynamiques du refroidissement a jet, particulierement dans le cas d'ecoulements turbulents. Un manque de comprehension de l'aerodynamique a l'interieur de ces espaces confinees peut mener a des changements de transfert thermique qui sont inattendus, ce qui augmente le risque de fluage. Il est donc d'interet pour l'industrie aerospatiale et l'academie de poursuivre la recherche dans l'aerodynamique des jets turbulents impactant les parois courbes. Les jets impactant les surfaces courbes ont deja fait l'objet de nombreuses etudes. Par contre des conditions oscillatoires observees en laboratoire se sont averees difficiles a reproduire en numerique, puisque les structures d'ecoulements impactants des parois concaves sont fortement dependantes de la turbulence et des effets instationnaires. Une etude experimentale fut realisee a l'institut PPRIME a l'Universite de Poitiers afin d'observer le phenomene d'oscillation dans le jet. Une serie d'essais ont verifie les conditions d'ecoulement laminaires et turbulentes, toutefois le cout des essais experimentaux a seulement permis d'avoir un apercu du phenomene global. Une deuxieme serie d'essais fut realisee numeriquement a l'Universite de Moncton avec l'outil OpenFOAM pour des conditions d'ecoulement laminaire et bidimensionnel. Cette etude a donc comme but de poursuivre l'enquete de l'aerodynamique oscillatoire des jets impactant des parois courbes, mais pour un regime d'ecoulement transitoire, turbulent

Topographic imprint on chemical weathering in deeply weathered soil-mantled landscapes (southern Brazil)

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Vanacker, Veerle; Schoonejans, Jerome; Ameijeiras-Marino, Yolanda; Opfergelt, Sophie; Minella, Jean

2017-04-01

The regolith mantle is defined as the thin layer of unconsolidated material overlaying bedrock that contributes to shape the Earth's surface. The development of the regolith mantle in a landscape is the result of in-situ weathering, atmospheric input and downhill transport of weathering products. Bedrock weathering - the physical and chemical transformations of rock to soil - contributes to the vertical development of the regolith layer through downward propagation of the weathering front. Lateral transport of soil particles, aggregates and solutes by diffusive and concentrated particle and solute fluxes result in lateral redistribution of weathering products over the hillslope. In this study, we aim to expand the empirical basis on long-term soil evolution at the landscape scale through a detailed study of soil weathering in subtropical soils. Spatial variability in chemical mass fluxes and weathering intensity were studied along two toposequences with similar climate, lithology and vegetation but different slope morphology. This allowed us to isolate the topographic imprint on chemical weathering and soil development. The toposequences have convexo-concave slope morphology, and eight regolith profiles were analysed involving the flat upslope, steep midslope and flat toeslope part. Our data show a clear topographic imprint on soil development. Along hillslope, the chemical weathering intensity of the regolith profiles increases with distance from the crest. In contrast to the upslope positions, the soils in the basal concavities develop on in-situ and transported regolith. While the chemical weathering extent on the slope convexities (the upslope profiles) is similar for the steep and gentle toposequence, there is a clear difference in the rate of increase of the chemical weathering extent with distance from the crest. The increase of chemical weathering extent along hillslope is highest for the steep toposequence, suggesting that topography enhances soil particle

Valvular Heart Disease in Heart Failure

Directory of Open Access Journals (Sweden)

Giuseppe MC Rosano

2017-01-01

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

Heart Health - Brave Heart

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

Water experiment of high-speed, free-surface, plane jet along concave wall

International Nuclear Information System (INIS)

Nakamura, Hideo; Ida, Mizuho; Kato, Yoshio; Maekawa, Hiroshi; Itoh, Kazuhiro; Kukita, Yutaka

1997-01-01

In the International Fusion Materials Irradiation Facility (IFMIF), an intense 14 MeV neutron beam will be generated in the high-speed liquid lithium (Li) plane jet target flowing along concave wall in vacuum. As part of the conceptual design activity (CDA) of the IFMIF, the stability of the plane liquid jet flow was studied experimentally with water in a well-defined channel geometry for non-heating condition. A two-dimensional double-reducer nozzle being newly proposed for the IFMIF target successfully provided a high-speed (≤ 17 m/s) stable water jet with uniform velocity distribution at the nozzle exit without flow separation in the nozzle. The free surface of the jet was covered by two-dimensional and/or three-dimensional waves, the size of which did not change much over the tested jet length of ∼130 mm. The jet velocity profile changed around the nozzle exit from uniform to that of free-vortex flow where the product of the radius of stream line and local velocity is constant in the jet thickness. The jet thickness increased immediately after exiting the nozzle because of the velocity profile change. The predicted jet thickness by a modified one-dimensional momentum model agreed with the data well. (author)

On conservation of renewable resources with stock-dependent return and non-concave production

International Nuclear Information System (INIS)

Olson, Lars J.; Roy, Santanu

1994-05-01

An analysis is presented of the intertemporal choice foundations underlying the conservation or extinction of renewable resources when the resource production function is non-concave and the immediate return function depends on both current consumption and the size of the resource stock. This case may exhibit nonlinear dynamics and extinction is possible from high stocks even if conservation occurs from lower stocks. The paper focusses on the influence of preferences and the production function on the efficiency of: global conservation, the existence of a safe standard of conservation, or extinction. We show that conservation is efficient under weaker conditions than the 'δ-productivity' requirements derived in models where return function is not stock-dependent. The marginal rate of substitution between investment and the stock plays an important role in addition to the discount factor and the marginal productivity of the resource. Extinction need not be optimal even if the intrinsic growth rate of the resource is less than the external rate of return. Our analysis demonstrates the potential role of taxes, subsidies, demand forces, and harvest costs in determining the efficiency of conservation or extinction. 3 figs., 1 appendix, 24 refs

On conservation of renewable resources with stock-dependent return and non-concave production

Energy Technology Data Exchange (ETDEWEB)

Olson, Lars J. [Department of Agricultural and Resource Economics, University of Maryland, College Park, MD (United States); Roy, Santanu [Econometric Institute, Erasmus University, Rotterdam (Netherlands)

1994-05-01

An analysis is presented of the intertemporal choice foundations underlying the conservation or extinction of renewable resources when the resource production function is non-concave and the immediate return function depends on both current consumption and the size of the resource stock. This case may exhibit nonlinear dynamics and extinction is possible from high stocks even if conservation occurs from lower stocks. The paper focusses on the influence of preferences and the production function on the efficiency of: global conservation, the existence of a safe standard of conservation, or extinction. We show that conservation is efficient under weaker conditions than the `{delta}-productivity` requirements derived in models where return function is not stock-dependent. The marginal rate of substitution between investment and the stock plays an important role in addition to the discount factor and the marginal productivity of the resource. Extinction need not be optimal even if the intrinsic growth rate of the resource is less than the external rate of return. Our analysis demonstrates the potential role of taxes, subsidies, demand forces, and harvest costs in determining the efficiency of conservation or extinction. 3 figs., 1 appendix, 24 refs.

Micro-concave waveguide antenna for high photon extraction from nitrogen vacancy centers in nanodiamond

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Rajasekharan, Ranjith; Kewes, Günter; Djalalian-Assl, Amir; Ganesan, Kumaravelu; Tomljenovic-Hanic, Snjezana; McCallum, Jeffrey C.; Roberts, Ann; Benson, Oliver; Prawer, Steven

2015-01-01

The negatively charged nitrogen-vacancy colour center (NV− center) in nanodiamond is an excellent single photon source due to its stable photon generation in ambient conditions, optically addressable nuclear spin state, high quantum yield and its availability in nanometer sized crystals. In order to make practical devices using nanodiamond, highly efficient and directional emission of single photons in well-defined modes, either collimated into free space or waveguides are essential. This is a Herculean task as the photoluminescence of the NV centers is associated with two orthogonal dipoles arranged in a plane perpendicular to the NV defect symmetry axis. Here, we report on a micro-concave waveguide antenna design, which can effectively direct single photons from any emitter into either free space or into waveguides in a narrow cone angle with more than 80% collection efficiency irrespective of the dipole orientation. The device also enhances the spontaneous emission rate which further increases the number of photons available for collection. The waveguide antenna has potential applications in quantum cryptography, quantum computation, spectroscopy and metrology. PMID:26169682

Three-Dimensional Steady Supersonic Euler Flow Past a Concave Cornered Wedge with Lower Pressure at the Downstream

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Qu, Aifang; Xiang, Wei

2018-05-01

In this paper, we study the stability of the three-dimensional jet created by a supersonic flow past a concave cornered wedge with the lower pressure at the downstream. The gas beyond the jet boundary is assumed to be static. It can be formulated as a nonlinear hyperbolic free boundary problem in a cornered domain with two characteristic free boundaries of different types: one is the rarefaction wave, while the other one is the contact discontinuity, which can be either a vortex sheet or an entropy wave. A more delicate argument is developed to establish the existence and stability of the square jet structure under the perturbation of the supersonic incoming flow and the pressure at the downstream. The methods and techniques developed here are also helpful for other problems involving similar difficulties.

Automatic moment segmentation and peak detection analysis of heart sound pattern via short-time modified Hilbert transform.

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Sun, Shuping; Jiang, Zhongwei; Wang, Haibin; Fang, Yu

2014-05-01

This paper proposes a novel automatic method for the moment segmentation and peak detection analysis of heart sound (HS) pattern, with special attention to the characteristics of the envelopes of HS and considering the properties of the Hilbert transform (HT). The moment segmentation and peak location are accomplished in two steps. First, by applying the Viola integral waveform method in the time domain, the envelope (E(T)) of the HS signal is obtained with an emphasis on the first heart sound (S1) and the second heart sound (S2). Then, based on the characteristics of the E(T) and the properties of the HT of the convex and concave functions, a novel method, the short-time modified Hilbert transform (STMHT), is proposed to automatically locate the moment segmentation and peak points for the HS by the zero crossing points of the STMHT. A fast algorithm for calculating the STMHT of E(T) can be expressed by multiplying the E(T) by an equivalent window (W(E)). According to the range of heart beats and based on the numerical experiments and the important parameters of the STMHT, a moving window width of N=1s is validated for locating the moment segmentation and peak points for HS. The proposed moment segmentation and peak location procedure method is validated by sounds from Michigan HS database and sounds from clinical heart diseases, such as a ventricular septal defect (VSD), an aortic septal defect (ASD), Tetralogy of Fallot (TOF), rheumatic heart disease (RHD), and so on. As a result, for the sounds where S2 can be separated from S1, the average accuracies achieved for the peak of S1 (AP₁), the peak of S2 (AP₂), the moment segmentation points from S1 to S2 (AT₁₂) and the cardiac cycle (ACC) are 98.53%, 98.31% and 98.36% and 97.37%, respectively. For the sounds where S1 cannot be separated from S2, the average accuracies achieved for the peak of S1 and S2 (AP₁₂) and the cardiac cycle ACC are 100% and 96.69%. Copyright © 2014 Elsevier Ireland Ltd. All

Dirty snowball - now is too primitive for a scientific description of comets

Science.gov (United States)

Kochemasov, G.

Success of the "Deep Space 1" scientists which acquired excellent pictures of comet Borrelli, brings comets into the family of small celestial bodies with common regularities of shaping. Often attracted accidental impact process never can explain constantly repeated shapes of small bodies. Understanding their shaping is important in view of coming missions to small bodies. "Orbits make structures". This fundamental notion is unfolded into 4 theorems of planetary tectonics [1]: 1. Celestial bodies are dichotomic; 2. -" - are sectoral; 3. -"- are granular; 4. Angular momenta of different level blocks tend to be equal. All these general rules of shaping and structurization are a consequence of interferences of warping any body standing planetary waves due to inertia forces acting in any moving in non-circular orbit body. Dichotomy is the most global tectonic feature due to the fundamental waves (wave 1). It is typical to all planetary spheres. In Earth it is in the core, mantle, crust, atmosphere. At Venus it is very pronounced in the crust and in atmosphere: lying Y-feature and inverse C-feature in the cloud layer. Coherent martian lithosphere- atmosphere dichotomies are well known. In small bodies the dichotomy is specifically pronounced as ubiquitous convexo -concave shape. Most detailed studied at Eros this shape was also observed at comet Halley and recently at Borrelli. Borrelli's convex extended half is strongly jagged (not easy to find a place for landing!), the contracted concave half spits out tremendous tail. Surface areas around the tail outlets are whitish and lighter than surroundings. It seems that the gas-dust material squeezed out of interiors not only disappears in space but leaves traces on the concave surface. The concave hemisphere has shorter radius than the convex one and tends to compensate loosing angular momentum by denser material extracted from interiors (Theorem 4 [1];compare with the basaltic Pacific hemisphere opposed by the granitic

Hartley and Itokawa: small comet and asteroid with similar morphologies and structures

Science.gov (United States)

Kochemasov, G. G.

2011-10-01

" Orbits ma ke s tructures " [1-3]. This three-word sentence means that as all cosmic bodies moves in non-circular keplerian orbits they all are subjected to an action of inertia -gravity warping waves. These waves arise in bodies as a result of periodically changing accelerations causing inertia-gravity forces. These forces are absorbed by bodies masses and make them to warp. This warping is smoothed by gravity making globular shapes of the larger bodies. But smaller bodies with rather weak gravity keep their warped shapes. The wave nature warping happens in four interfering direct ions (ortho - and diagonal) and in various wavelengths. The fundamental wave 1 long 2π R makes ubiquitous tectonic dichotomy: an oppos ition of the uplifted segment-hemisphere and the subsided one. For small bodies a result of this is in their convexo-concave shape [3] (Fig. 1-7). The uplifted bulging segment expands and is breaking by cracks, faults, rifts. The opposed subsided concave segment contracts. As a result in the middle of an oblong body is formed a narrow thoroughly squeezed and degassed portion - a neck or waist (wringed out wet linen). Subsequently here at a weakened place could happen a break - formation of binaries, polycomponental bodies, satellites. Figures 1 to 4 show development stages of small bodies leading to a full separation of two parts. Traces of warping waves of four directions are often seen on surfaces of many celestial bodies as cross -cutting lineations. A recent example of the small core of the Hartley 2 comet (2 km long) is very impressive. At received points of view are clearly seen at least three ortho- and diagonal lineations often marked by small outgassing craters (Fig. 1). Crossing lineations produce square forms (craters ) earlier s een on the Eros ' s urface. Wave comp res s ion lineations make the Hart ley 2 t o appear as a wafer ca ke. A " wa is t" (neck) is formed as a res ult of nearing a concave depression, from one side, and deep cracks

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

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

2007-08-01

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

Heart transplantation in adults with congenital heart disease.

Science.gov (United States)

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

2017-05-01

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

Women's Heart Disease: Heart Attack Symptoms

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

Heart murmurs

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

Prospective Heart Tracking for Whole-heart Magnetic Resonance Angiography

Science.gov (United States)

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

2015-01-01

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

Heart Failure

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

Heart MRI

Science.gov (United States)

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

Heart Health - Heart Disease: Symptoms, Diagnosis, Treatment

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

Heart Health: The Heart Truth Campaign 2009

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

Women's Heart Disease: Heart Disease Risk Factors

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

Génesis de la estructura arqueada de la Sierra de las Cabras al Gibalto (Subbético, provincias de Málaga y Granada, España

Directory of Open Access Journals (Sweden)

Sanz de Galdeano, C.

2012-12-01

Full Text Available The Subbetic sierras of Las Cabras to the Gibalto form an arched structure, giving it a high relief, constituted by many tectonic slices, verging to the South in its southern border and to the North and West in its concave border. Although it could be interpreted as an allochthonous structure, really is rooted in the transitional area between the Median and the Internal Subbetic. Several local factors have influenced this complex structure, but the final cause is the oblique collision (transpression of the In-ternal Zone against External Zone of the Betic Chain, producing an important strike-slip system.

Las sierras subbéticas de las Cabras al Gibalto forman una estructura arqueada, que da un fuerte relieve, constituida por escamas tectónicas, vergentes al sur en su borde convexo, meridional, y al nor-te y oeste en su borde cóncavo. Aunque podría interpretarse como una estructura alóctona, se en-cuentra enraizada en el área de tránsito entre el Subbético Medio y el Interno. En su génesis han in-fluido varios factores locales pero la causa que controla a todos ellos es la colisión oblicua, en trans-presión, de la Zona Interna Bética contra la Externa, que produjo un importante sistema de desgarre.

3D modelling of interaction of strongly nonlinear internal seiches with a concave lake topography and a phenomenon of the "lake monsters".

Science.gov (United States)

Terletska, Kateryna; Maderich, Vladimir; Brovchenko, Igor; Jung, Kyung Tae

2013-04-01

In the freshwater lakes in moderate latitudes stratification occurs as a result of the seasonal warming of the surface water layer. Than the intense wind surges (usually in autumn) tilt the surface and generate long basin-scale low-frequency standing internal waves (seiches). Depending on the initial interface tilt and stratification wide spectra of possible flow regimes can be observed [1]-[2].They varied from small amplitude symmetric seiches to large amplitude nonlinear waves.Nonlinearity leads to an asymmetry of internal waves and appearance of the surge or bore and further disintegration of it on a sequence of solitary waves. In present study degeneration of the strongly nonlinear internal seiches in elongated lakes with a concave "spoon-like" topography is investigated.Two different three-dimensional non-hydrostatic free-surface numerical models are used to investigate degeneration of large internal waves and its subsequent interaction with the concave lake slope. One of this model is non-hydrostatic model [3] and the other is a well-known MIT model. At first we consider idealized elongated elliptic-shape lake with the dimension of 5 km X 1 km with the maximal depth 30 m. The stratification in lake is assumed to be given in a form of the tangent function with a density difference between upper and lower layers 2 kgm-3 . It is assumed that motion in such lake is initiated by inclination of thermocline on a certain angle. Than lake adjusts to return to its original state producing internal seiches which begin interacting with a bottom topography. The process of degeneration of internal seiches in the lake with concave ends consist of chain of elementary processes: 1) steeping of long basin scale large amplitude wave, that evolve into internal surge, 2) surge interact with concave lake ends that leads the concentration of the flow and formation of down slope bottom jet along the lake axis, 3) due to cumulative effect local velocity in the jet accelerates up to

Characterizing potential heart agents with an isolated perfused heart system

International Nuclear Information System (INIS)

Pendleton, D.B.; Sands, H.; Gallagher, B.M.; Camin, L.L.

1984-01-01

The authors have used an isolated perfused heart system for characterizing potential myocardial perfusion radiopharamaceuticals. Rabbit or guinea pig (GP) hearts are removed and perfused through the aorta with a blood-free buffer. Heart rate and ventricular pressure are monitored as indices of viability. Tc-99m-MAA is 96-100% retained in these hearts, and Tc-99m human serum albumin shows less than 5% extraction. Tl-201 is 30-40% extracted. It is known that in-vivo, Tc-99m(dmpe)/sub 2/Cl/sub 2//sup +/ is taken up by rabbit heart but not by GP or human heart. Analogous results are obtained with the isolated perfused heart model, where the complex is extracted well by the isolated rabbit heart (24%) but not by the GP heart (<5%). Values are unchanged if human, rabbit or GP blood is mixed and co-injected with the complex. Tc-99m)dmpe)/sub 3//sup +/ is also taken up by rabbit but not by GP hearts in-vivo. However, isolated perfused hearts of both species extract this complex well (45-52%). Heart uptake is diminished to <7% if the complex is pre-equilibrated with human blood. GP blood produces a moderate inhibition (in GP hearts only) and rabbit blood has no effect. This suggests that a human or GP blood factor may have a significant effect on heart uptake of this complex. Tc-99m(CN-t-butyl)/sub 6//sup +/ is taken up well by both rabbit and GP hearts in-vivo, and is extracted 100% by both isolated perfused hearts. Heart retention remains high (73-75%) in the presence of human blood

Heart Diseases

Science.gov (United States)

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

Heart Transplantation

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

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

Science.gov (United States)

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

2014-03-01

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

Pediatric heart surgery

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

Combined heart-kidney transplantation after total artificial heart insertion.

Science.gov (United States)

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

2015-01-01

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

Healthy Body, Happy Heart: Improve Your Heart Health

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

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

Science.gov (United States)

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

2015-01-01

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

Enlarged Heart

Science.gov (United States)

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

A Linear Programming Approach to Routing Control in Networks of Constrained Nonlinear Positive Systems with Concave Flow Rates

Science.gov (United States)

Arneson, Heather M.; Dousse, Nicholas; Langbort, Cedric

2014-01-01

We consider control design for positive compartmental systems in which each compartment's outflow rate is described by a concave function of the amount of material in the compartment.We address the problem of determining the routing of material between compartments to satisfy time-varying state constraints while ensuring that material reaches its intended destination over a finite time horizon. We give sufficient conditions for the existence of a time-varying state-dependent routing strategy which ensures that the closed-loop system satisfies basic network properties of positivity, conservation and interconnection while ensuring that capacity constraints are satisfied, when possible, or adjusted if a solution cannot be found. These conditions are formulated as a linear programming problem. Instances of this linear programming problem can be solved iteratively to generate a solution to the finite horizon routing problem. Results are given for the application of this control design method to an example problem. Key words: linear programming; control of networks; positive systems; controller constraints and structure.

Women's Heart Disease: Join the Heart Truth Community

Science.gov (United States)

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

Heart Health: Learn the Truth About Your Heart

Science.gov (United States)

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

Simple, heart-smart substitutions

Science.gov (United States)

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

Flat-ramp vs. convex-concave thrust geometries in a deformable hanging wall: new insights from analogue modeling experiments

Science.gov (United States)

Almeida, Pedro; Tomas, Ricardo; Rosas, Filipe; Duarte, Joao; Terrinha, Pedro

2015-04-01

Different modes of strain accommodation affecting a deformable hanging-wall in a flat-ramp-flat thrust system were previously addressed through several (sandbox) analog modeling studies, focusing on the influence of different variables, such as: a) thrust ramp dip angle and friction (Bonini et al, 2000); b) prescribed thickness of the hanging-wall (Koy and Maillot, 2007); and c) sin-thrust erosion (compensating for topographic thrust edification, e.g. Persson and Sokoutis, 2002). In the present work we reproduce the same experimental procedure to investigate the influence of two different parameters on hanging-wall deformation: 1) the geometry of the thrusting surface; and 2) the absence of a velocity discontinuity (VD) that is always present in previous similar analogue modeling studies. Considering the first variable we use two end member ramp geometries, flat-ramp-flat and convex-concave, to understand the control exerted by the abrupt ramp edges in the hanging-wall stress-strain distribution, comparing the obtain results with the situation in which such edge singularities are absent (convex-concave thrust ramp). Considering the second investigated parameter, our motivation was the recognition that the VD found in the different analogue modeling settings simply does not exist in nature, despite the fact that it has a major influence on strain accommodation in the deformable hanging-wall. We thus eliminate such apparatus artifact from our models and compare the obtained results with the previous ones. Our preliminary results suggest that both investigated variables play a non-negligible role on the structural style characterizing the hanging-wall deformation of convergent tectonic settings were such thrust-ramp systems were recognized. Acknowledgments This work was sponsored by the Fundação para a Ciência e a Tecnologia (FCT) through project MODELINK EXPL/GEO-GEO/0714/2013. Pedro Almeida wants to thank to FCT for the Ph.D. grant (SFRH/BD/52556/2014) under the

Coronary heart disease

Science.gov (United States)

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

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

NARCIS (Netherlands)

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

2007-01-01

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

Heart regeneration.

Science.gov (United States)

Breckwoldt, Kaja; Weinberger, Florian; Eschenhagen, Thomas

2016-07-01

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

HEART OF MYTH – HEART OF SCIENCE Part I

Science.gov (United States)

Bound Alberti, Fay

2015-01-01

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

Women and Heart Disease: Sharing Advice from the Heart

Science.gov (United States)

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

Advanced Heart Failure

Science.gov (United States)

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

Types of Heart Failure

Science.gov (United States)

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

Employment after heart transplantation among adults with congenital heart disease.

Science.gov (United States)

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

2017-12-01

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

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

Science.gov (United States)

Zhang, Qing-Jun; Liu, Zhi-Ping

2015-01-01

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

Heart rate index

DEFF Research Database (Denmark)

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

1992-01-01

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

Dimensional analysis of heart rate variability in heart transplant recipients

Energy Technology Data Exchange (ETDEWEB)

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

1987-01-01

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

Potential implications of the helical heart in congenital heart defects.

Science.gov (United States)

Corno, Antonio F; Kocica, Mladen J

2007-01-01

The anatomic and functional observations made by Francisco Torrent-Guasp, in particular his discovery of the helical ventricular myocardial band (HVMB), have challenged what has been taught to cardiologists and cardiac surgeons over centuries. A literature debate is ongoing, with interdependent articles and comments from supporters and critics. Adequate understanding of heart structure and function is obviously indispensable for the decision-making process in congenital heart defects. The HVMB described by Torrent-Guasp and the potential impact on the understanding and treatment of congenital heart defects has been analyzed in the following settings: embryology, ventriculo-arterial discordance (transposition of great arteries), Ebstein's anomaly, pulmonary valve regurgitation after repair of tetralogy of Fallot, Ross operation, and other congenital heart defects. The common structural spiral feature is only one of the elements responsible for the functional interaction of right and left ventricles, and understanding the form/function relationship in congenital heart defects is more difficult than for acquired heart disease because of the variety and complexity of congenital heart defects. Individuals involved in the care of patients with congenital heart defects have to be stimulated to consider further investigations and alternative surgical strategies.

Million Hearts: Key to Collaboration to Reduce Heart Disease

Science.gov (United States)

Brinkman, Patricia

2016-01-01

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

Wine and heart health

Science.gov (United States)

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

Wavefront error measurement of the concave ellipsoidal mirrors of the METIS coronagraph on ESA Solar Orbiter mission

Science.gov (United States)

Sandri, P.

2017-12-01

The paper describes the alignment technique developed for the wavefront error measurement of ellipsoidal mirrors presenting a central hole. The achievement of a good alignment with a classic setup at the finite conjugates when mirrors are uncoated cannot be based on the identification and materialization at naked eye of the retro-reflected spot by the mirror under test as the intensity of the retro-reflected spot results to be ≈1E-3 of the intensity of the injected laser beam of the interferometer. We present the technique developed for the achievement of an accurate alignment in the setup at the finite conjugate even in condition of low intensity based on the use of an autocollimator adjustable in focus position and a small polished flat surface on the rear side of the mirror. The technique for the alignment has successfully been used for the optical test of the concave ellipsoidal mirrors of the METIS coronagraph of the ESA Solar Orbiter mission. The presented method results to be advantageous in terms of precision and of time saving also when the mirrors are reflective coated and integrated into their mechanical hardware.

Men and Heart Disease

Science.gov (United States)

... Pressure Salt Cholesterol Million Hearts® WISEWOMAN Men and Heart Disease Fact Sheet Recommend on Facebook Tweet Share Compartir Source: Interactive Atlas of Heart Disease and Stroke Heart Disease Facts in Men Heart disease is the leading ...

Classes of Heart Failure

Science.gov (United States)

... Introduction Types of Heart Failure Classes of Heart Failure Heart Failure in Children Advanced Heart Failure • Causes and ... and Advanced HF • Tools and Resources • Personal Stories Heart Failure Questions to Ask Your Doctor Use these questions ...

Heart valve surgery

Science.gov (United States)

... replacement; Valve repair; Heart valve prosthesis; Mechanical valves; Prosthetic valves ... surgery. Your heart valve has been damaged by infection ( endocarditis ). You have received a new heart valve ...

Heart failure - tests

Science.gov (United States)

CHF - tests; Congestive heart failure - tests; Cardiomyopathy - tests; HF - tests ... the best test to: Identify which type of heart failure (systolic, diastolic, valvular) Monitor your heart failure and ...

Engineered Heart Repair.

Science.gov (United States)

Fujita, B; Zimmermann, W-H

2017-08-01

There is a pressing need for the development of advanced heart failure therapeutics. Current state-of-the-art is protection from neurohumoral overstimulation, which fails to address the underlying cause of heart failure, namely loss of cardiomyocytes. Implantation of stem cell-derived cardiomyocytes via tissue-engineered myocardium is being advanced to realize the remuscularization of the failing heart. Here, we discuss pharmacological challenges pertaining to the clinical translation of tissue-engineered heart repair with a focus on engineered heart muscle (EHM). © 2017 American Society for Clinical Pharmacology and Therapeutics.

El método de las ponderaciones en el problema fraccional lineal multiobjetivo

Directory of Open Access Journals (Sweden)

Hernández Huelin, Mónica.

2003-01-01

Full Text Available Dentro de la programación matemática no lineal, el problema que se ha abordado más en términos teóricos y algorítmicos es el problema convexo. Cuando estamos ante una función fraccional, no tenemos convexidad, pero sí otras buenas propiedades que pueden hacer más o menos fácil la elaboración de algoritmos propios de resolución del problema. En este trabajo nos centramos en adaptar el Método de las Ponderaciones, uno de los métodos clásicos de resolución a priori del problema multiobjetivo convexo, al caso no convexo de objetivos fraccionales lineales. Dado que no tenemos convexidad ni concavidad de las funciones objetivo, y esta condición es básica para la aplicación de dicho método, estudiaremos este inconveniente con profundidad, estableciendo condiciones bajo las cuales resulta válido este método como generador de los conjuntos eficiente y débilmente eficiente de nuestro problema. Para ello se plantea la necesidad de un estudio detallado de los conceptos de pseudoconvexidad, cuasiconvexidad, invexidad, pseudoinvexidad, etc.. Ofreceremos además un contraejemplo que nos muestra que, si no se dan las condiciones que previamente estableceremos, el Método de las Ponderaciones no es válido para generar todo el conjunto débilmente eficiente de nuestro problema

Heart Transplant in Patients with Predominantly Rheumatic Valvular Heart Disease.

Science.gov (United States)

Rosa, Vitor E E; Lopes, Antonio S S A; Accorsi, Tarso A D; Fernandes, Joao Ricardo C; Spina, Guilherme S; Sampaio, Roney O; Bacal, Fernando; Tarasoutchi, Flavio

2015-09-01

International records indicate that only 2.6% of patients with heart transplants have valvular heart disease. The study aim was to evaluate the epidemiological and clinical profile of patients with valvular heart disease undergoing heart transplantation. Between 1985 and 2013, a total of 569 heart transplants was performed at the authors' institution. Twenty patients (13 men, seven women; mean age 39.5 +/- 15.2 years) underwent heart transplant due to structural (primary) valvular disease. Analyses were made of the patients' clinical profile, laboratory data, echocardiographic and histopathological data, and mortality and rejection. Of the patients, 18 (90%) had a rheumatic etiology, with 85% having undergone previous valve surgery (45% had one or more operations), and 95% with a normal functioning valve prosthesis at the time of transplantation. Atrial fibrillation was present in seven patients (35%), while nine (45%) were in NYHA functional class IV and eight (40%) in class III. The indication for cardiac transplantation was refractory heart failure in seven patients (35%) and persistent NYHA class III/IV in ten (50%). The mean left ventricular ejection fraction (LVEF) was 26.6 +/- 7.9%. The one-year mortality was 20%. Histological examination of the recipients' hearts showed five (27.7%) to have reactivated rheumatic myocarditis without prior diagnosis at the time of transplantation. Univariate analysis showed that age, gender, LVEF, rheumatic activity and rejection were not associated with mortality at one year. Among the present patient cohort, rheumatic heart disease was the leading cause of heart transplantation, and a significant proportion of these patients had reactivated myocarditis diagnosed in the histological analyses. Thus, it appears valid to investigate the existence of rheumatic activity, especially in valvular cardiomyopathy with severe systolic dysfunction before transplantation.

Hypertensive heart disease

Science.gov (United States)

... page: //medlineplus.gov/ency/article/000163.htm Hypertensive heart disease To use the sharing features on this page, please enable JavaScript. Hypertensive heart disease refers to heart problems that occur because of ...

An automated three-dimensional detection and segmentation method for touching cells by integrating concave points clustering and random walker algorithm.

Directory of Open Access Journals (Sweden)

Yong He

Full Text Available Characterizing cytoarchitecture is crucial for understanding brain functions and neural diseases. In neuroanatomy, it is an important task to accurately extract cell populations' centroids and contours. Recent advances have permitted imaging at single cell resolution for an entire mouse brain using the Nissl staining method. However, it is difficult to precisely segment numerous cells, especially those cells touching each other. As presented herein, we have developed an automated three-dimensional detection and segmentation method applied to the Nissl staining data, with the following two key steps: 1 concave points clustering to determine the seed points of touching cells; and 2 random walker segmentation to obtain cell contours. Also, we have evaluated the performance of our proposed method with several mouse brain datasets, which were captured with the micro-optical sectioning tomography imaging system, and the datasets include closely touching cells. Comparing with traditional detection and segmentation methods, our approach shows promising detection accuracy and high robustness.

Multivariate Autoregressive Model Based Heart Motion Prediction Approach for Beating Heart Surgery

Directory of Open Access Journals (Sweden)

Fan Liang

2013-02-01

Full Text Available A robotic tool can enable a surgeon to conduct off-pump coronary artery graft bypass surgery on a beating heart. The robotic tool actively alleviates the relative motion between the point of interest (POI on the heart surface and the surgical tool and allows the surgeon to operate as if the heart were stationary. Since the beating heart's motion is relatively high-band, with nonlinear and nonstationary characteristics, it is difficult to follow. Thus, precise beating heart motion prediction is necessary for the tracking control procedure during the surgery. In the research presented here, we first observe that Electrocardiography (ECG signal contains the causal phase information on heart motion and non-stationary heart rate dynamic variations. Then, we investigate the relationship between ECG signal and beating heart motion using Granger Causality Analysis, which describes the feasibility of the improved prediction of heart motion. Next, we propose a nonlinear time-varying multivariate vector autoregressive (MVAR model based adaptive prediction method. In this model, the significant correlation between ECG and heart motion enables the improvement of the prediction of sharp changes in heart motion and the approximation of the motion with sufficient detail. Dual Kalman Filters (DKF estimate the states and parameters of the model, respectively. Last, we evaluate the proposed algorithm through comparative experiments using the two sets of collected vivo data.

Heart disease and diet

Science.gov (United States)

Diet - heart disease; CAD - diet; Coronary artery disease - diet; Coronary heart disease - diet ... diet and lifestyle can reduce your risk of: Heart disease, heart attacks, and stroke Conditions that lead ...

Heart-Health Screenings

Science.gov (United States)

... Tools For Your Heart Health • Watch, Learn & Live Animations Library Subscribe to Heart Insight magazine and monthly ... in Spanish . Popular Articles 1 Understanding Blood Pressure Readings 2 Sodium and Salt 3 Heart Attack Symptoms ...

Simulation of Blood flow in Artificial Heart Valve Design through Left heart

Science.gov (United States)

Hafizah Mokhtar, N.; Abas, Aizat

2018-05-01

In this work, an artificial heart valve is designed for use in real heart with further consideration on the effect of thrombosis, vorticity, and stress. The design of artificial heart valve model is constructed by Computer-aided design (CAD) modelling and simulated using Computational fluid dynamic (CFD) software. The effect of blood flow pattern, velocity and vorticity of the artificial heart valve design has been analysed in this research work. Based on the results, the artificial heart valve design shows that it has a Doppler velocity index that is less than the allowable standards for the left heart with values of more than 0.30 and less than 2.2. These values are safe to be used as replacement of the human heart valve.

Heart attack first aid

Science.gov (United States)

First aid - heart attack; First aid - cardiopulmonary arrest; First aid - cardiac arrest ... A heart attack occurs when the blood flow that carries oxygen to the heart is blocked. The heart muscle ...

Open heart surgery

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/002950.htm Open heart surgery To use the sharing features on this ... large arteries connected to the heart. The term "open heart surgery" means that you are connected to a ...

Left heart catheterization

Science.gov (United States)

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

Right heart ventriculography

Science.gov (United States)

Angiography - right heart ... moved forward into the right side of the heart. As the catheter is advanced, the doctor can ... is injected into the right side of the heart. It helps the cardiologist determine the size and ...

Congenital heart disease

Science.gov (United States)

Congenital heart disease (CHD) is a problem with the heart's structure and function that is present at birth. ... Fraser CD, Kane LC. Congenital heart disease. In: Townsend CM Jr, ... Sabiston Textbook of Surgery: The Biological Basis of Modern ...

"The Heart Game"

DEFF Research Database (Denmark)

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

2016-01-01

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

Pericarditis - after heart attack

Science.gov (United States)

... include: A previous heart attack Open heart surgery Chest trauma A heart attack that has affected the thickness of your heart muscle Symptoms Symptoms include: Anxiety Chest pain from the swollen pericardium rubbing on the ...

Chronic heart failure

OpenAIRE

Hopper, Ingrid; Easton, Kellie

2017-01-01

1. The common symptoms and signs of chronic heart failure are dyspnoea, ankle swelling, raised jugular venous pressure and basal crepitations. Other conditions may be confused with chronic heart failure, including dependent oedema or oedema due to renal or hepatic disease. Shortness of breath may be due to respiratory disease or severe anaemia. Heart failure secondary to lung disease (cor pulmonale) should be distinguished from congestive cardiac failure. Heart failure may also present with l...

Heart Failure

OpenAIRE

McMurray, John; Ponikowski, Piotr

2011-01-01

Heart failure occurs in 3% to 4% of adults aged over 65 years, usually as a consequence of coronary artery disease or hypertension, and causes breathlessness, effort intolerance, fluid retention, and increased mortality. The 5-year mortality in people with systolic heart failure ranges from 25% to 75%, often owing to sudden death following ventricular arrhythmia. Risks of cardiovascular events are increased in people with left ventricular systolic dysfunction (LVSD) or heart failure.

Limited-Access Heart Surgery

Science.gov (United States)

... on the side of the chest. With traditional open heart surgery, the incision is usually 6 to 8 ... attached to a heart-lung machine. In traditional open heart surgery, patients would be connected to the heart- ...

Heart Diseases and Disorders

Science.gov (United States)

... Resources Heart Diseases & Disorders Back to Patient Resources Heart Diseases & Disorders Millions of people experience irregular or abnormal ... harmless and happen in healthy people free of heart disease. However, some abnormal heart rhythms can be serious ...

Heart failure - surgeries and devices

Science.gov (United States)

... surgery; HF - surgery; Intra-aortic balloon pumps - heart failure; IABP - heart failure; Catheter based assist devices - heart failure ... problem may cause heart failure or make heart failure worse. Heart valve surgery may be needed to repair or ...

Fabrication of a roller type PDMS stamp using SU-8 concave molds and its application for roll contact printing

International Nuclear Information System (INIS)

Park, Jongho; Kim, Beomjoon

2016-01-01

Continuous fabrication of micropatterns at low-cost is attracting attention in various applications within industrial fields. To meet such demands, we have demonstrated a roll contact printing technique, using roller type polydimethylsiloxane (PDMS) stamps with roll-to-flat and roll-to-roll stages. Roller type PDMS stamps for roll contact printing were fabricated using a custom-made metal support and SU-8 microstructures fabricated on concave substrates as a mold. The molding/casting method which we developed here provided faster and easier fabrication than conventional methods for roller type stamps. Next, roll contact printing was performed using fabricated roller type PDMS stamps with roll-to-flat and roll-to-roll stages. Patterns with minimum widths of 3 μm and 2.1 μm were continuously fabricated for each stage, respectively. In addition, the relationship between applied pressures and dimensional changes of roll contact printed patterns was investigated. Finally, we confirmed that roll contact printing and the new fabrication method for roller stamps presented in this study demonstrated the feasibility for industrial applications. (paper)

Heart failure - home monitoring

Science.gov (United States)

... this page: //medlineplus.gov/ency/patientinstructions/000113.htm Heart failure - home monitoring To use the sharing features on ... your high blood pressure Fast food tips Heart failure - discharge Heart failure - fluids and diuretics Heart failure - what to ...

False Heart Rate Feedback and the Perception of Heart Symptoms in Patients with Congenital Heart Disease and Anxiety

NARCIS (Netherlands)

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

2009-01-01

Background Little is known about the mechanisms explaining an increased perception of heart symptoms in congenital heart disease (ConHD). In the present study, it was suggested that a combination of high trait anxiety and disease history increases the perception of heart symptoms. Purpose It was

False heart rate feedback and the perception of heart symptoms in patients with congenital heart disease and anxiety

NARCIS (Netherlands)

Karsdorp, P.A.; Kindt, M.; Rietveld, S.; Everaerd, W.; Mulder, B.J.M.

2009-01-01

Background: Little is known about the mechanisms explaining an increased perception of heart symptoms in congenital heart disease (ConHD). In the present study, it was suggested that a combination of high trait anxiety and disease history increases the perception of heart symptoms. Purpose: It was

The Interior City. Infinity and Concavity in the No-Stop City(1970-1971

Directory of Open Access Journals (Sweden)

Pablo Martínez Capdevila

2013-10-01

Full Text Available AbstractIn the late 60s it had become clear how the environment technification had allowed some typologies (supermarkets, car parks, factories to reach potentially unlimited built depths becoming, therefore, independent from the outside. The No-Stop City is born from a very simple idea: to extend this technification to the totality of built reality encompassing, not only almost all functions, but ultimately, the whole city. This operation has paradoxical effects: as architecture grows, it loses most of the features that have traditionally defined it. A dissolution by hypertrophy that gives rise to an homogeneous, concave and potentially infinite space.But beyond the pure technical feasibility, there are two key influences, seemingly contradictory, that explain this endeavor for an interior and endless city: Marxism and Pop Art. The project is, in many senses, a built manifesto reflecting the militancy of the group members within the Italian Marxism. But it is also the embodiment of the group's declared interest in Pop Art, popular culture and mass society. The cross-influence of communism and consumerism explains this "quantitative utopia" in which the society and the factory, the production and consumption, would match. A city based on the centrality of consumer products and the subsequent loss of prominence of architecture, in which the urban phenomenon, while spreading endlessly over territory, ignoring its rural exteriority, dissolves the home as a sphere of privacy, ignoring its domestic interiority.A project, also in the wake of Marshall McLuhan, that illustrates like few others the conversion of the urbane into a virtually omnipresent "condition" and that still interrogates us with questions that are, on the other hand, eternal: What is a building? What is a city?Key wordsBranzi, dissolution, pop, Marxism, neo-avant-garde

Protect Your Heart: Check Food Labels to Make Heart-Healthy Choices

Science.gov (United States)

... Protein 15g Total Amounts To make heart-healthy food choices, look at the totals and cut back on • ... Toolkit No. 8: Protect Your Heart: Make Smart Food Choices • Toolkit No. 9: Protect Your Heart: Choose Fats ...

Artificial heart

Energy Technology Data Exchange (ETDEWEB)

1984-10-18

Super-pure plutonium-238 could use heat produced during fission to power an implanted artificial heart. Three model hearts have worked for some time. Concern that excess heat would make the procedure unsafe for humans has broadened the search for another energy source, such as electrohydraulic drive or an external power battery. A back pack approach may provide an interim solution until materials are developed which can withstand heart activity and be small enough for implantation.

Heart attack - discharge

Science.gov (United States)

... and lifestyle Cholesterol - drug treatment Controlling your high blood pressure Deep vein thrombosis - discharge Dietary fats explained Fast food tips Heart attack - discharge Heart attack - what to ask your doctor Heart bypass ... pacemaker - discharge High blood pressure - what to ask your doctor How to read ...

Heart Valve Diseases

Science.gov (United States)

Your heart has four valves. Normally, these valves open to let blood flow through or out of your heart, and then shut to keep it from flowing ... close tightly. It's one of the most common heart valve conditions. Sometimes it causes regurgitation. Stenosis - when ...

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

Science.gov (United States)

Tutarel, Oktay

2014-09-01

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

Air Quality and Heart Health: An Emerging Topic for Heart Month

Science.gov (United States)

Air Quality and Heart Health: An Emerging Topic for Heart Month: Ambient air particle pollution increases short- and long-term cardiovascular morbidity and mortality. Older-people, those with pre-existing heart disease and lung disease and diabetes are at higher risk. Mechanism...

Parental overprotection and heart-focused anxiety in adults with congenital heart disease.

Science.gov (United States)

Ong, Lephuong; Nolan, Robert P; Irvine, Jane; Kovacs, Adrienne H

2011-09-01

The care of adult patients with congenital heart disease (CHD) is challenging from a mental health perspective, as these patients continue to face a variety of biopsychosocial issues that may impact emotional functioning. Despite these issues, there are limited data on the psychosocial functioning of adults with CHD, and there are no data on the impact of parental overprotection on heart-focused anxiety in this patient population. The aim of this study was to examine the relationships between patient recollections of parental overprotection and current heart-focused anxiety in adults with CHD. A cross-sectional sample of 190 adult patients with CHD (51% male; mean age = 32.28, SD = 11.86 years) completed validated measures of perceived parental overprotection (Parental Bonding Instrument) and heart-focused anxiety (Cardiac Anxiety Questionnaire). The results indicated that perceived parental overprotection (β = 0.19, p = 0.02) and heart defect complexity (β = 0.17, p = 0.03) were significantly related to heart-focused anxiety. Contrary to hypotheses, perceived parental overprotection did not vary as a function of heart defect complexity (F (2, 169) = 0.02, p = 0.98). Perceived parental overprotection and heart defect complexity are associated with heart-focused anxiety in adults with congenital heart disease. These results can inform the development of clinical interventions aimed at improving the psychosocial adjustment of this patient population.

Heart Age PSA (:60)

Centers for Disease Control (CDC) Podcasts

This 60 second public service announcement is based on the September 2015 CDC Vital Signs report. Your heart age is the age of your heart and blood vessels as a result of your risk factors for heart attack and stroke. If you smoke or have high blood pressure, your heart age will be much higher than your actual age. Learn what you can do to lower your heart age and keep it low.

Mending Hearts and Building Bridges: The Save a Child's Heart Foundation

NARCIS (Netherlands)

Sasson, L.; Tamir, A.; Houri, S.; Betawe, A.; Darwazah, A.K.; Kapusta, L.; Pivnick, L.E.; Goldman, B.G.

2016-01-01

CONTEXT: Save a Child's Heart addresses the challenges of heart care for children in underdeveloped countries. OBJECTIVE: Save a Child's Heart has created a center of excellence for pediatric cardiac care at the Wolfson Medical Center in Israel, helped develop partner sites for evaluation and

Heart Attack

Science.gov (United States)

... family history of heart attack race – African Americans, Mexican Americans, Native Americans, and native Hawaiians are at ... Your doctor will prescribe the medicines that are right for you. If you have had a heart ...

Heart Disease

Science.gov (United States)

... it may be caused by diseases, such as connective tissue disorders, excessive iron buildup in your body (hemochromatosis), the buildup of abnormal proteins (amyloidosis) or by some cancer treatments. Causes of heart infection A heart infection, ...

Human heart by art.

Science.gov (United States)

Tamir, Abraham

2012-11-01

Heart is of great importance in maintaining the life of the body. Enough to stop working for a few minutes to cause death, and hence the great importance in physiology, medicine, and research. This fact was already emphasized in the Bible in the Book of Proverbs, chapter 4 verse 23: "Keep your heart with all diligence, for out of it is the wellspring of life." Art was able to demonstrate the heart from various aspects; realistically, as done by Leonardo de Vinci who demonstrated the halves of the heart and its blood vessels. Symbolically, as a source of life, the heart was demonstrated by the artist Mrs. Erlondeiel, as a caricature by Salvador Dali, as an open heart by Sawaya, etc. Finally, it should be emphasized that different demonstrations of the human heart by many artworks make this most important organ of our body (that cannot be seen from outside) more familiar and clearer to us. And this is the purpose of this article-to demonstrate the heart through a large number of artworks of different kinds.

The total artificial heart.

Science.gov (United States)

Cook, Jason A; Shah, Keyur B; Quader, Mohammed A; Cooke, Richard H; Kasirajan, Vigneshwar; Rao, Kris K; Smallfield, Melissa C; Tchoukina, Inna; Tang, Daniel G

2015-12-01

The total artificial heart (TAH) is a form of mechanical circulatory support in which the patient's native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart. Currently, the TAH is approved for use in end-stage biventricular heart failure as a bridge to heart transplantation. However, with an increasing global burden of cardiovascular disease and congestive heart failure, the number of patients with end-stage heart failure awaiting heart transplantation now far exceeds the number of available hearts. As a result, the use of mechanical circulatory support, including the TAH and left ventricular assist device (LVAD), is growing exponentially. The LVAD is already widely used as destination therapy, and destination therapy for the TAH is under investigation. While most patients requiring mechanical circulatory support are effectively treated with LVADs, there is a subset of patients with concurrent right ventricular failure or major structural barriers to LVAD placement in whom TAH may be more appropriate. The history, indications, surgical implantation, post device management, outcomes, complications, and future direction of the TAH are discussed in this review.

Metaiodobenzylguanidine and heart rate variability in heart failure

International Nuclear Information System (INIS)

Kurata, Chinori; Shouda, Sakae; Mikami, Tadashi; Uehara, Akihiko; Ishikawa, Keiko; Tawarahara, Kei; Nakano, Tomoyasu; Matoh, Fumitaka; Takeuchi, Kazuhiko

1998-01-01

It is assumed that the low-frequency power (LF) of heart rate variability (HRV) increases with progress of congestive heart failure (CHF), therefore positively correlating with cardiac 123 I-metaiodobenzylguanidine (MIBG) washout. It is demonstrated here that HRV, including normalized LF, correlated inversely with MIBG washout and positively with the ratio of heart-to-mediastinum MIBG activity in controls and CHF patients, whereas these correlations were not observed within CHF patients. Thus MIBG washout may increase and HRV including normalized LF may decrease with CHF, although the HRV and MIBG measures may not similarly change in proportion to the severity of the cardiac autonomic dysfunction in CHF. (author)

Metaiodobenzylguanidine and heart rate variability in heart failure

Energy Technology Data Exchange (ETDEWEB)

Kurata, Chinori; Shouda, Sakae; Mikami, Tadashi; Uehara, Akihiko; Ishikawa, Keiko [Hamamatsu Univ., Shizuoka (Japan). School of Medicine; Tawarahara, Kei; Nakano, Tomoyasu; Matoh, Fumitaka; Takeuchi, Kazuhiko

1998-10-01

It is assumed that the low-frequency power (LF) of heart rate variability (HRV) increases with progress of congestive heart failure (CHF), therefore positively correlating with cardiac {sup 123}I-metaiodobenzylguanidine (MIBG) washout. It is demonstrated here that HRV, including normalized LF, correlated inversely with MIBG washout and positively with the ratio of heart-to-mediastinum MIBG activity in controls and CHF patients, whereas these correlations were not observed within CHF patients. Thus MIBG washout may increase and HRV including normalized LF may decrease with CHF, although the HRV and MIBG measures may not similarly change in proportion to the severity of the cardiac autonomic dysfunction in CHF. (author)

Heart Truth

Science.gov (United States)

... health! Get a free badge or banner to post to your website or blog. Are you at risk for heart disease? Here's how to find out . Planning to use The Heart Truth logo? Check out our logo guidelines and downloads. ...

A healthy heart is not a metronome: an integrative review of the heart's anatomy and heart rate variability.

Science.gov (United States)

Shaffer, Fred; McCraty, Rollin; Zerr, Christopher L

2014-01-01

Heart rate variability (HRV), the change in the time intervals between adjacent heartbeats, is an emergent property of interdependent regulatory systems that operate on different time scales to adapt to challenges and achieve optimal performance. This article briefly reviews neural regulation of the heart, and its basic anatomy, the cardiac cycle, and the sinoatrial and atrioventricular pacemakers. The cardiovascular regulation center in the medulla integrates sensory information and input from higher brain centers, and afferent cardiovascular system inputs to adjust heart rate and blood pressure via sympathetic and parasympathetic efferent pathways. This article reviews sympathetic and parasympathetic influences on the heart, and examines the interpretation of HRV and the association between reduced HRV, risk of disease and mortality, and the loss of regulatory capacity. This article also discusses the intrinsic cardiac nervous system and the heart-brain connection, through which afferent information can influence activity in the subcortical and frontocortical areas, and motor cortex. It also considers new perspectives on the putative underlying physiological mechanisms and properties of the ultra-low-frequency (ULF), very-low-frequency (VLF), low-frequency (LF), and high-frequency (HF) bands. Additionally, it reviews the most common time and frequency domain measurements as well as standardized data collection protocols. In its final section, this article integrates Porges' polyvagal theory, Thayer and colleagues' neurovisceral integration model, Lehrer et al.'s resonance frequency model, and the Institute of HeartMath's coherence model. The authors conclude that a coherent heart is not a metronome because its rhythms are characterized by both complexity and stability over longer time scales. Future research should expand understanding of how the heart and its intrinsic nervous system influence the brain.

Heart Transplantation in Congenital Heart Disease: In Whom to Consider and When?

Science.gov (United States)

Attenhofer Jost, Christine H.; Schmidt, Dörthe; Huebler, Michael; Balmer, Christian; Noll, Georg; Caduff, Rosmarie; Greutmann, Matthias

2013-01-01

Due to impressive improvements in surgical repair options, even patients with complex congenital heart disease (CHD) may survive into adulthood and have a high risk of end-stage heart failure. Thus, the number of patients with CHD needing heart transplantation (HTx) has been increasing in the last decades. This paper summarizes the changing etiology of causes of death in heart failure in CHD. The main reasons, contraindications, and risks of heart transplantation in CHD are discussed and underlined with three case vignettes. Compared to HTx in acquired heart disease, HTx in CHD has an increased risk of perioperative death and rejection. However, outcome of HTx for complex CHD has improved over the past 20 years. Additionally, mechanical support options might decrease the waiting list mortality in the future. The number of patients needing heart-lung transplantation (especially for Eisenmenger's syndrome) has decreased in the last years. Lung transplantation with intracardiac repair of a cardiac defect is another possibility especially for patients with interatrial shunts. Overall, HTx will remain an important treatment option for CHD in the near future. PMID:23577237

La iridotomía periférica con Nd YAG láser en el síndrome de dispersión pigmentaria/glaucoma pigmentario Nd YAG laser peripheral iridotomy in the pigment dispersion syndrome/pigmentary glaucoma

Directory of Open Access Journals (Sweden)

Francisco García González

2002-06-01

Full Text Available En 13 ojos con diagnóstico de síndrome de dispersión pigmentaria y 5 con glaucoma pigmentario, inicialmente se evaluaron la presión intraocular, los signos de dispersión pigmentaria, la relación excavación-papila y las alteraciones del campo visual; se realizó iridotomía periférica Nd YAG láser en los ojos con este síndrome y trabeculectomía a los que presentaban glaucoma pigmentario. Se chequearon cada 4 meses hasta 24 meses. Once ojos con iris cóncavo mostraron aplanamiento del iris y 2 con iris convexos no variaron con la iridotomía láser; en los 18 ojos disminuyeron evidentemente los signos de dispersión pigmentaria y la presión intraocular permaneció estable, la cual mejoró en los tratados con la trabeculectomía. En el síndrome de dispersión pigmentaria es muy frecuente la configuración cóncava del iris; la iridotomía lo aplana y evita el roce iridozonular, disminuyendo la dispersión y deposición de pigmento que prevendría el aumento de la presión intraocular y el glaucoma pigmentario.The intraocular pressure, the signs of pigment dispersion, the excavation-papilla relation and the alterations of the visual field were initially evaluated in 13 eyes with diagnosis of pigment dispersion syndrome and 5 with pigmentary glaucoma. Nd YAG laser perypheral iridotomy was performed in patients with this syndrome, whereas those who presented pigmentary glaucoma underwent trabeculectomy. They were checked every 4 months up to 24 months. 11 eyes with concave iris showed flattening of the iris and 2 with convex iris did not vary with laser iridotomy. An evident reduction of the signs of pigment dispersion was observed in the 18 eyes. The intraocular pressure remained stable and it improved in those treated with trabeculectomy. In the pigment dispersion syndrome it is very frequent the concave configuration of the iris; the iridotomy flattens it and avoids the iridozonular friction, reducing the dispersion and deposition of

The Danish Heart Registry

DEFF Research Database (Denmark)

Özcan, Cengiz; Juel, Knud; Lassen, Jens Flensted

2016-01-01

AIM: The Danish Heart Registry (DHR) seeks to monitor nationwide activity and quality of invasive diagnostic and treatment strategies in patients with ischemic heart disease as well as valvular heart disease and to provide data for research. STUDY POPULATION: All adult (≥15 years) patients...... undergoing coronary angiography (CAG), percutaneous coronary intervention (PCI), coronary artery bypass grafting, and heart valve surgery performed across all Danish hospitals were included. MAIN VARIABLES: The DHR contains a subset of the data stored in the Eastern and Western Denmark Heart Registries (EDHR...

Construct validity of the Heart Failure Screening Tool (Heart-FaST) to identify heart failure patients at risk of poor self-care: Rasch analysis.

Science.gov (United States)

Reynolds, Nicholas A; Ski, Chantal F; McEvedy, Samantha M; Thompson, David R; Cameron, Jan

2018-02-14

The aim of this study was to psychometrically evaluate the Heart Failure Screening Tool (Heart-FaST) via: (1) examination of internal construct validity; (2) testing of scale function in accordance with design; and (3) recommendation for change/s, if items are not well adjusted, to improve psychometric credential. Self-care is vital to the management of heart failure. The Heart-FaST may provide a prospective assessment of risk, regarding the likelihood that patients with heart failure will engage in self-care. Psychometric validation of the Heart-FaST using Rasch analysis. The Heart-FaST was administered to 135 patients (median age = 68, IQR = 59-78 years; 105 males) enrolled in a multidisciplinary heart failure management program. The Heart-FaST is a nurse-administered tool for screening patients with HF at risk of poor self-care. A Rasch analysis of responses was conducted which tested data against Rasch model expectations, including whether items serve as unbiased, non-redundant indicators of risk and measure a single construct and that rating scales operate as intended. The results showed that data met Rasch model expectations after rescoring or deleting items due to poor discrimination, disordered thresholds, differential item functioning, or response dependence. There was no evidence of multidimensionality which supports the use of total scores from Heart-FaST as indicators of risk. Aggregate scores from this modified screening tool rank heart failure patients according to their "risk of poor self-care" demonstrating that the Heart-FaST items constitute a meaningful scale to identify heart failure patients at risk of poor engagement in heart failure self-care. © 2018 John Wiley & Sons Ltd.

Pediatric heart surgery - discharge

Science.gov (United States)

... discharge; Heart valve surgery - children - discharge; Heart surgery - pediatric - discharge; Heart transplant - pediatric - discharge ... Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016:chap 434. ...

Radiation-induced heart injury

International Nuclear Information System (INIS)

Suzuki, Yoshihiko; Niibe, Hideo

1975-01-01

In order to identify radiation-induced heart injury and to differentiate it from heart disease, an attempt was made to clarify post-irradiation heart injury by investigating the histological changes which occur during the internal between the irradiation and the time of demonstrable histological changes. A study was made of 83 autopsies in which most of the primary neoplasms were breast cancers, lung cancers and mediastinal tumors. In 43 of these autopsies the heart had been irradiated. Sixty eight dd-strain mice were also used for microautoradiographic study. Histological changes in the heart were observed in 27 of the 43 cases receiving irradiation. The limit of the tolerance dose to the heart for indicating histological changes was 1220 ret in humans. The latent period without histological changes was 2.7 months after initiation of radiation therapy. Greater heart injury was observed after re-irradiation or after the combined therapy of radiation and chemotherapy especially mitomycin (MMC). The histological findings after treatment with MMC were similar to those of radiation-induced heart injury. Results of the study indicate that the damage is secondary to radiation-induced changes of the vascula connective tissue. (Evans, G.)

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

Science.gov (United States)

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

2015-01-01

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

Design and performance of heart assist or artificial heart control systems

Science.gov (United States)

Webb, J. A., Jr.; Gebben, V. D.

1978-01-01

The factors leading to the design of a controlled driving system for either a heart assist pump or artificial heart are discussed. The system provides square pressure waveform to drive a pneumatic-type blood pump. For assist usage the system uses an R-wave detector circuit that can detect the R-wave of the electrocardiogram in the presence of electrical disturbances. This circuit provides a signal useful for synchronizing an assist pump with the natural heart. It synchronizes a square wave circuit, the output of which is converted into square waveforms of pneumatic pressure suitable for driving both assist device and artificial heart. The pressure levels of the driving waveforms are controlled by means of feedback channels to maintain physiological regulation of the artificial heart's output flow. A more compact system that could achieve similar regulatory characteristics is also discussed.

Carcinoid heart disease.

Science.gov (United States)

Hassan, Saamir A; Banchs, Jose; Iliescu, Cezar; Dasari, Arvind; Lopez-Mattei, Juan; Yusuf, Syed Wamique

2017-10-01

Rare neuroendocrine tumours (NETs) that most commonly arise in the gastrointestinal tract can lead to carcinoid syndrome and carcinoid heart disease. Patients with carcinoid syndrome present with vasomotor changes, hypermotility of the gastrointestinal system, hypotension and bronchospasm. Medical therapy for carcinoid syndrome, typically with somatostatin analogues, can help control symptoms, inhibit tumour progression and prolong survival. Carcinoid heart disease occurs in more than 50% of these patients and is the initial presentation of carcinoid syndrome in up to 20% of patients. Carcinoid heart disease has characteristic findings of plaque-like deposits composed of smooth muscle cells, myofibroblasts, extracellular matrix and an overlying endothelial layer which can lead to valve dysfunction. Valvular dysfunction can lead to oedema, ascites and right-sided heart failure. Medical therapy of carcinoid heart disease is limited to symptom control and palliation. Valve surgery for carcinoid heart disease should be considered for symptomatic patients with controlled metastatic carcinoid syndrome. A multidisciplinary approach is needed to guide optimal management. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Assessment of potential heart donors: A statement from the French heart transplant community.

Science.gov (United States)

Dorent, Richard; Gandjbakhch, Estelle; Goéminne, Céline; Ivanes, Fabrice; Sebbag, Laurent; Bauer, Fabrice; Epailly, Eric; Boissonnat, Pascale; Nubret, Karine; Amour, Julien; Vermes, Emmanuelle; Ou, Phalla; Guendouz, Soulef; Chevalier, Philippe; Lebreton, Guillaume; Flecher, Erwan; Obadia, Jean-François; Logeart, Damien; de Groote, Pascal

2018-02-01

Assessment of potential donors is an essential part of heart transplantation. Despite the shortage of donor hearts, donor heart procurement from brain-dead organ donors remains low in France, which may be explained by the increasing proportion of high-risk donors, as well as the mismatch between donor assessment and the transplant team's expectations. Improving donor and donor heart assessment is essential to improve the low utilization rate of available donor hearts without increasing post-transplant recipient mortality. This document provides information to practitioners involved in brain-dead donor management, evaluation and selection, concerning the place of medical history, electrocardiography, cardiac imaging, biomarkers and haemodynamic and arrhythmia assessment in the characterization of potential heart donors. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Heart Age PSA (:60)

Centers for Disease Control (CDC) Podcasts

2015-09-01

This 60 second public service announcement is based on the September 2015 CDC Vital Signs report. Your heart age is the age of your heart and blood vessels as a result of your risk factors for heart attack and stroke. If you smoke or have high blood pressure, your heart age will be much higher than your actual age. Learn what you can do to lower your heart age and keep it low.  Created: 9/1/2015 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 9/1/2015.

Heart failure as an endpoint in heart failure and non-heart failure cardiovascular clinical trials: the need for a consensus definition

DEFF Research Database (Denmark)

Zannad, F.; Stough, W.G.; Pitt, B.

2008-01-01

Specific criteria have been established to define the occurrence of myocardial infarction (MI) and stroke in cardiovascular clinical trials, but there is not a consistent definition for heart failure. Heart failure events appear to occur at a rate that is similar to stroke and MI in trials...... of hypertension, hyperlipidaemia, diabetes, and coronary heart disease, yet a consistent approach to defining heart failure events has not yet been realized. The wide range of definitions used in clinical trials makes it difficult to interpret new data in the context of existing literature. This inconsistency has...... led to challenges in determining the incidence of heart failure in cardiovascular studies and the effects of interventions on these endpoints. This paper examines issues related to defining heart failure events in cardiovascular clinical trials and presents a definition to formally address this issue...

Heart Attack Recovery FAQs

Science.gov (United States)

... recommendations to make a full recovery. View an animation of a heart attack . Heart Attack Recovery Questions ... Support Network Popular Articles 1 Understanding Blood Pressure Readings 2 Sodium and Salt 3 Heart Attack Symptoms ...

Heart disease and depression

Science.gov (United States)

... gov/ency/patientinstructions/000790.htm Heart disease and depression To use the sharing features on this page, ... a heart attack or heart surgery Signs of Depression It is pretty common to feel down or ...

Heart Disease Risk Factors

Science.gov (United States)

... About CDC.gov . Home About Heart Disease Coronary Artery Disease Heart Attack Heart Attack Signs and Symptoms ... Privacy FOIA No Fear Act OIG 1600 Clifton Road Atlanta , GA 30329-4027 USA 800-CDC-INFO ( ...

Heart Failure in Women

Science.gov (United States)

Bozkurt, Biykem; Khalaf, Shaden

2017-01-01

Heart failure is an important cause of morbidity and mortality in women, and they tend to develop it at an older age compared to men. Heart failure with preserved ejection fraction is more common in women than in men and accounts for at least half the cases of heart failure in women. When comparing men and women who have heart failure and a low left ventricular ejection fraction, the women are more symptomatic and have a similarly poor outcome. Overall recommendations for guideline-directed medical therapies show no differences in treatment approaches between men and women. Overall, women are generally underrepresented in clinical trials for heart failure. Further studies are needed to shed light into different mechanisms, causes, and targeted therapies of heart failure in women. PMID:29744014

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

Science.gov (United States)

Osadchii, Oleg E

2014-12-01

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

Getting a New Heart

Science.gov (United States)

... may be able to replace it with an artificial (man-made) valve. Cardiac size reduction . During this procedure, your doctor removes a piece of the heart muscle from an enlarged heart. This makes your heart ...

Congenital Heart Information Network

Science.gov (United States)

... heart defects. Important Notice The Congenital Heart Information Network website is temporarily out of service. Please join ... and Uwe Baemayr for The Congenital Heart Information Network Exempt organization under Section 501(c)3. Copyright © ...

A wear simulation study of nanostructured CVD diamond-on-diamond articulation involving concave/convex mating surfaces

Science.gov (United States)

Baker, Paul A.; Thompson, Raymond G.; Catledge, Shane A.

2015-01-01

Using microwave-plasma Chemical Vapor Deposition (CVD), a 3-micron thick nanostructured-diamond (NSD) layer was deposited onto polished, convex and concave components that were machined from Ti-6Al-4V alloy. These components had the same radius of curvature, 25.4mm. Wear testing of the surfaces was performed by rotating articulation of the diamond-deposited surfaces (diamond-on-diamond) with a load of 225N for a total of 5 million cycles in bovine serum resulting in polishing of the diamond surface and formation of very shallow, linear wear grooves of less than 50nm depth. The two diamond surfaces remained adhered to the components and polished each other to an average surface roughness that was reduced by as much as a factor of 80 for the most polished region located at the center of the condyle. Imaging of the surfaces showed that the initial wearing-in phase of diamond was only beginning at the end of the 5 million cycles. Atomic force microscopy, scanning electron microscopy, Raman spectroscopy, and surface profilometry were used to characterize the surfaces and verify that the diamond remained intact and uniform over the surface, thereby protecting the underlying metal. These wear simulation results show that diamond deposition on Ti alloy has potential application for joint replacement devices with improved longevity over existing devices made of cobalt chrome and ultra-high molecular weight polyethylene (UHMWPE). PMID:26989457

Do neonatal mouse hearts regenerate following heart apex resection?

DEFF Research Database (Denmark)

Andersen, Ditte Caroline; Ganesalingam, Suganya; Jensen, Charlotte Harken

2014-01-01

The mammalian heart has generally been considered nonregenerative, but recent progress suggests that neonatal mouse hearts have a genuine capacity to regenerate following apex resection (AR). However, in this study, we performed AR or sham surgery on 400 neonatal mice from inbred and outbred...

Heart Disease and Stroke Statistics

Science.gov (United States)

... Media for Heart.org Heart and Stroke Association Statistics Each year, the American Heart Association, in conjunction ... health and disease in the population. Heart & Stroke Statistics FAQs What is Prevalence? Prevalence is an estimate ...

Illegal Drugs and Heart Disease

Science.gov (United States)

... Venous Thromboembolism Aortic Aneurysm More Illegal Drugs and Heart Disease Updated:May 3,2018 Most illegal drugs can ... www.dea.gov/druginfo/factsheets.shtml Alcohol and Heart Disease Caffeine and Heart Disease Tobacco and Heart Disease ...

Risks for Heart Disease & Stroke

Science.gov (United States)

... Prevent Risks for Heart Disease & Stroke Risks for Heart Disease & Stroke About 1.5 million heart attacks and ... can’t change some of your risks for heart disease and stroke, but you can manage many of ...

Managing Feelings about Heart Failure

Science.gov (United States)

... About Heart Failure Module 6: Managing Feelings About Heart Failure Download Module Order Hardcopy Heart failure can cause ... professional help for emotional problems. Common Feelings About Heart Failure It is common for people to feel depressed ...

Heart rate monitoring mobile applications

OpenAIRE

Chaudhry, Beenish M.

2016-01-01

Total number of times a heart beats in a minute is known as the heart rate. Traditionally, heart rate was measured using clunky gadgets but these days it can be measured with a smartphone?s camera. This can help you measure your heart rate anywhere and at anytime, especially during workouts so you can adjust your workout intensity to achieve maximum health benefits. With simple and easy to use mobile app, ?Unique Heart Rate Monitor?, you can also maintain your heart rate history for personal ...

The heart and the liver

DEFF Research Database (Denmark)

Møller, Søren; Dümcke, Christine Winkler; Krag, Aleksander

2009-01-01

Cardiac failure affects the liver and liver dysfunction affects the heart. Chronic and acute heart failure can lead to cardiac cirrhosis and cardiogenic ischemic hepatitis. These conditions may impair liver function and treatment should be directed towards the primary heart disease and seek...... against the heart failure. Transjugular intrahepatic portosystemic shunt insertion and liver transplantation affect cardiac function in portal hypertensive patients and cause stress to the cirrhotic heart, with a risk of perioperative heart failure. The risk and prevalence of coronary artery disease...

Heart Truth for Women: If You Have Heart Disease

Science.gov (United States)

... failure and a damaged heart muscle. My experience with heart disease started with typical symptoms. It took me some time to get my strength back, but now I exercise regularly and eat healthy foods. To ... counseling, and training. This part of rehab helps you understand your ...

Target Heart Rates

Science.gov (United States)

... Check Recipe Certification Program Nutrition Requirements Heart-Check Professional Resources Contact the Heart-Check Certification Program Simple Cooking and Recipes Dining Out Choosing a Restaurant Deciphering ...

Optimization of radiotherapy to target volumes with concave outlines: target-dose homogenization and selective sparing of critical structures by constrained matrix inversion

Energy Technology Data Exchange (ETDEWEB)

Colle, C; Van den Berge, D; De Wagter, C; Fortan, L; Van Duyse, B; De Neve, W

1995-12-01

The design of 3D-conformal dose distributions for targets with concave outlines is a technical challenge in conformal radiotherapy. For these targets, it is impossible to find beam incidences for which the target volume can be isolated from the tissues at risk. Commonly occurring examples are most thyroid cancers and the targets located at the lower neck and upper mediastinal levels related to some head and neck. A solution to this problem was developed, using beam intensity modulation executed with a multileaf collimator by applying a static beam-segmentation technique. The method includes the definition of beam incidences and beam segments of specific shape as well as the calculation of segment weights. Tests on Sherouse`s GRATISTM planning system allowed to escalate the dose to these targets to 65-70 Gy without exceeding spinal cord tolerance. Further optimization by constrained matrix inversion was investigated to explore the possibility of further dose escalation.

Heart valve surgery - discharge

Science.gov (United States)

... ACC guideline for the management of patients with valvular heart disease: executive summary: a report of the American College ... Editorial team. Related MedlinePlus Health Topics Heart Surgery Heart Valve Diseases Browse the Encyclopedia A.D.A.M., Inc. ...

Heart rate monitoring mobile applications.

Science.gov (United States)

Chaudhry, Beenish M

2016-01-01

Total number of times a heart beats in a minute is known as the heart rate. Traditionally, heart rate was measured using clunky gadgets but these days it can be measured with a smartphone's camera. This can help you measure your heart rate anywhere and at anytime, especially during workouts so you can adjust your workout intensity to achieve maximum health benefits. With simple and easy to use mobile app, 'Unique Heart Rate Monitor', you can also maintain your heart rate history for personal reflection and sharing with a provider.

Heart Disease in Women

Science.gov (United States)

... United States, 1 in 4 women dies from heart disease. The most common cause of heart disease in both men and women is narrowing ... the blood vessels that supply blood to the heart itself. This is called coronary artery disease, and ...

Heart failure - medicines

Science.gov (United States)

CHF - medicines; Congestive heart failure - medicines; Cardiomyopathy - medicines; HF - medicines ... You will need to take most of your heart failure medicines every day. Some medicines are taken ...

[Obesity and heart].

Science.gov (United States)

Svačina, Štěpán

2014-12-01

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

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

Science.gov (United States)

Gepstein, Lior; Kehat, Izhak

2005-02-01

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

Una descomposición convexa

Directory of Open Access Journals (Sweden)

Mario Lomelí - Haro

2014-01-01

Full Text Available Dada una colección P de puntos en el plano, una descomposición convexa de P es un conjunto Γ de polígonos convexos convértices en P que satisfacen lo siguiente: La unión de todos los elementos de Γ es el cierre convexo de P, cada elemento de Γ es vacío (no contiene a ningún otro elemento de P en su interior y para cualesquiera 2 elementos diferentes en Γ sus interiores son disjuntos (se intersecarán en a lo más una arista. Únicamente se sabe que existen descomposiciones convexas con a lo más 7n/5 elementos para toda colección de n puntos. En este trabajo diremos cómo obtener una descomposición convexa específica de P con a lo más 3n/ 2 elementos.

Nurses' decision making in heart failure management based on heart failure certification status.

Science.gov (United States)

Albert, Nancy M; Bena, James F; Buxbaum, Denise; Martensen, Linda; Morrison, Shannon L; Prasun, Marilyn A; Stamp, Kelly D

Research findings on the value of nurse certification were based on subjective perceptions or biased by correlations of certification status and global clinical factors. In heart failure, the value of certification is unknown. Examine the value of certification based nurses' decision-making. Cross-sectional study of nurses who completed heart failure clinical vignettes that reflected decision-making in clinical heart failure scenarios. Statistical tests included multivariable linear, logistic and proportional odds logistic regression models. Of nurses (N = 605), 29.1% were heart failure certified, 35.0% were certified in another specialty/job role and 35.9% were not certified. In multivariable modeling, nurses certified in heart failure (versus not heart failure certified) had higher clinical vignette scores (p = 0.002), reflecting higher evidence-based decision making; nurses with another specialty/role certification (versus no certification) did not (p = 0.62). Heart failure certification, but not in other specialty/job roles was associated with decisions that reflected delivery of high-quality care. Copyright © 2018 Elsevier Inc. All rights reserved.

Panic Attack or Heart Attack?

Science.gov (United States)

... When in doubt about symptoms, seek care without delay to rule out heart disease. Heart disease affects your heart's ... which cause you concern, see your doctor without delay and ask for testing to rule out heart disease. 1 Gadolinium side effects could ...

Valvular heart disease

OpenAIRE

Gelson, E; Gatzoulis, M; Johnson, M

2007-01-01

Valvular disease may be unmasked in pregnancy when physiological changes increase demands on the heart. Women with valvular heart disease require close follow-up during pregnancy, delivery, and postpartum

CDC Vital Signs-Heart Age

Centers for Disease Control (CDC) Podcasts

This podcast is based on the September 2015 CDC Vital Signs report. Your heart age is the age of your heart and blood vessels as a result of your risk factors for heart attack and stroke. If you smoke or have high blood pressure, your heart age will be much higher than your actual age. Learn what you can do to lower your heart age and keep it low.

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

Science.gov (United States)

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

2017-12-01

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

Nuclear Heart Scan

Science.gov (United States)

... Home / Nuclear Heart Scan Nuclear Heart Scan Also known as Nuclear Stress Test , ... Learn More Connect With Us Contact Us Directly Policies Privacy Policy Freedom of Information Act (FOIA) Accessibility ...

Heart bypass surgery

Science.gov (United States)

Off-pump coronary artery bypass; OPCAB; Beating heart surgery; Bypass surgery - heart; CABG; Coronary artery bypass graft; Coronary artery bypass surgery; Coronary bypass surgery; Coronary artery disease - CABG; CAD - CABG; Angina - ...

Nutrition in Heart Failure

OpenAIRE

Reci Meseri

2013-01-01

Heart failure is defined as decreased ability of heart due to various reasons. It%u2019s seen 2-3% but the prevalence increases sharply after the age of seventy. The objectives of nutrition therapy in heart failure are to prevent from water retention and edema, to avoid from hard digestion and to offer a balanced diet. In order to avoid fluid retention and edema, daily sodium and fluid intake must be monitored carefully. Main dilemma of the heart failure patients is the obesity-cachexia dilem...

Atrial fibrillation, ischaemic heart disease, and the risk of death in patients with heart failure

DEFF Research Database (Denmark)

Pedersen, Ole Dyg; Søndergaard, Peter; Nielsen, Tonny

2006-01-01

AIMS: Atrial fibrillation (AF) is a risk factor for death in patients with a myocardial infarction, but highly variable results are reported in patients with heart failure. We studied the prognostic impact of AF in heart failure patients with and without ischaemic heart disease. METHODS AND RESULTS......), 1.02-1.23, P=0.018]. There was a significant interaction between the importance of AF and the presence of ischaemic heart disease (P=0.034). In patients with AF at the time of discharge and ischaemic heart disease, HR was 1.25 (95% CI: 1.09-1.42) and P... and without ischaemic heart disease, HR was 1.01 (95% CI: 0.88-1.16) and P=0.88. CONCLUSION: AF is associated with increased risk of death only in patients with ischaemic heart disease. This finding may explain the variable results of studies of the prognosis associated with AF in heart failure....

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

Science.gov (United States)

Villa, Chet R; Morales, David L S

2017-01-01

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

Heart Motion Prediction in Robotic-Assisted Beating Heart Surgery: A Nonlinear Fast Adaptive Approach

Directory of Open Access Journals (Sweden)

Fan Liang

2013-01-01

Full Text Available Off-pump Coronary Artery Bypass Graft (CABG surgery outperforms traditional on-pump surgery because the assisted robotic tools can alleviate the relative motion between the beating heart and robotic tools. Therefore, it is possible for the surgeon to operate on the beating heart and thus lessens post surgery complications for the patients. Due to the highly irregular and non-stationary nature of heart motion, it is critical that the beating heart motion is predicted in the model-based track control procedures. It is technically preferable to model heart motion in a nonlinear way because the characteristic analysis of 3D heart motion data through Bi-spectral analysis and Fourier methods demonstrates the involved nonlinearity of heart motion. We propose an adaptive nonlinear heart motion model based on the Volterra Series in this paper. We also design a fast lattice structure to achieve computational-efficiency for real-time online predictions. We argue that the quadratic term of the Volterra Series can improve the prediction accuracy by covering sharp change points and including the motion with sufficient detail. The experiment results indicate that the adaptive nonlinear heart motion prediction algorithm outperforms the autoregressive (AR and the time-varying Fourier-series models in terms of the root mean square of the prediction error and the prediction error in extreme cases.

The Palm-Heart Diameter: A Prospective Simple Screening Tool for Identifying Heart Enlargement

Directory of Open Access Journals (Sweden)

Adegbenro Omotuyi John Fakoya

2017-11-01

CONCLUSION: This study establishes the correlation between the palm and heart diameters. Since the heart tissue and the upper limb share a similar embryonic origin, being the mesoderm, this study prospects the fact that heart enlargement could be preliminarily identified by measuring the size of the hand.

HEART TRANSPLANTATION IN PATIENTS WITH PREVIOUS OPEN HEART SURGERY

Directory of Open Access Journals (Sweden)

R. Sh. Saitgareev

2016-01-01

Full Text Available Heart Transplantation (HTx to date remains the most effective and radical method of treatment of patients with end-stage heart failure. The defi cit of donor hearts is forcing to resort increasingly to the use of different longterm mechanical circulatory support systems, including as a «bridge» to the follow-up HTx. According to the ISHLT Registry the number of recipients underwent cardiopulmonary bypass surgery increased from 40% in the period from 2004 to 2008 to 49.6% for the period from 2009 to 2015. HTx performed in repeated patients, on the one hand, involves considerable technical diffi culties and high risks; on the other hand, there is often no alternative medical intervention to HTx, and if not dictated by absolute contradictions the denial of the surgery is equivalent to 100% mortality. This review summarizes the results of a number of published studies aimed at understanding the immediate and late results of HTx in patients, previously underwent open heart surgery. The effect of resternotomy during HTx and that of the specifi c features associated with its implementation in recipients previously operated on open heart, and its effects on the immediate and long-term survival were considered in this review. Results of studies analyzing the risk factors for perioperative complications in repeated recipients were also demonstrated. Separately, HTx risks after implantation of prolonged mechanical circulatory support systems were examined. The literature does not allow to clearly defi ning the impact factor of earlier performed open heart surgery on the course of perioperative period and on the prognosis of survival in recipients who underwent HTx. On the other hand, subject to the regular fl ow of HTx and the perioperative period the risks in this clinical situation are justifi ed as a long-term prognosis of recipients previously conducted open heart surgery and are comparable to those of patients who underwent primary HTx. Studies

Functional radioanatomy of the heart

International Nuclear Information System (INIS)

Tikhonov, K.B.

1990-01-01

Extensive data on radioanatomy of the heart and main vessels as applied to standard projections are presented. Anatomic structure evolution during heart cycle is described. A current trend towards complex examination of the heart and minor circulation vessels is illustrated, including digital roentgenography, digital subtraction angiography, nmr imaging, computerized tomography, radioisotope examination of the heart and positron emission tomography. Data testifying to essential effect of resperation phase and patient's placement on X-ray picture of the heart and blood flow in the lungs. 291 refs.; 131 figs

Semi-analytical computation of the acoustic field of a segment of a cylindrically concave transducer in lossless and attenuating media.

Science.gov (United States)

Karbeyaz, Başak Ulker; Miller, Eric L; Cleveland, Robin O

2007-02-01

Conventional ultrasound transducers used for medical diagnosis generally consist of linearly aligned rectangular apertures with elements that are focused in one plane. While traditional beamforming is easily accomplished with such transducers, the development of quantitative, physics-based imaging methods, such as tomography, requires an accurate, and computationally efficient, model of the field radiated by the transducer. The field can be expressed in terms of the Helmholtz-Kirchhoff integral; however, its direct numerical evaluation is a computationally intensive task. Here, a fast semianalytical method based on Stepanishen's spatial impulse response formulation [J. Acoust. Soc. Am. 49, 1627-1638 (1971)] is developed to compute the acoustic field of a rectangular element of cylindrically concave transducers in a homogeneous medium. The pressure field, for, lossless and attenuating media, is expressed as a superposition of Bessel functions, which can be evaluated rapidly. In particular, the coefficients of the Bessel series are frequency independent and need only be evaluated once for a given transducer. A speed up of two orders of magnitude is obtained compared to an optimized direct numerical integration. The numerical results are compared with Field II and the Fresnel approximation.

New Medications for Heart Failure

Science.gov (United States)

Gordin, Jonathan S.; Fonarow, Gregg C.

2016-01-01

Heart failure is common and results in substantial morbidity and mortality. Current guideline-based therapies for heart failure with reduced ejection fraction, including beta-blockers, angiotensin converting enzyme (ACE) inhibitors, and aldosterone antagonists aim to interrupt deleterious neurohormonal pathways and have shown significant success in reducing morbidity and mortality associated with heart failure. Continued efforts to further improve outcomes in patients with heart failure with reduced ejection fraction have led to the first new-in-class medications approved for heart failure since 2005, ivabradine and sacubitril/valsartan. Ivabradine targets the If channels in the sinoatrial node of the heart, decreasing heart rate. Sacubitril/valsartan combines a neprilysin inhibitor that increases levels of beneficial vasodilatory peptides with an angiotensin receptor antagonist. On a background of previously approved, guideline-directed medical therapies for heart failure, these medications have shown improved clinical outcomes ranging from decreased hospitalizations in a select group of patients to a reduction in all-cause mortality across all pre-specified subgroups. In this review, we will discuss the previously established guideline-directed medical therapies for heart failure with reduced ejection fraction, the translational research that led to the development of these new therapies, and the results from the major clinical trials of ivabradine and sacubitril/valsartan. PMID:27038558

The Heart of Coaching

Science.gov (United States)

Docheff, Dennis M.; Gerdes, Dan

2015-01-01

This article challenges coaches to address the more personal, human elements of coaching--the HEART of coaching. While there is much research on numerous aspects of coaching, this article provides ideas that make a lasting impact on the hearts of athletes. Using HEART as an acronym, five elements of effective coaching are presented: Humility,…

Effects of Liraglutide on Heart Rate and Heart Rate Variability

DEFF Research Database (Denmark)

Kumarathurai, Preman; Anholm, Christian; Larsen, Bjørn Strøier

2017-01-01

OBJECTIVE: Reduced heart rate variability (HRV) and increased heart rate (HR) have been associated with cardiovascular mortality. Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) increase HR, and studies have suggested that they may reduce HRV. We examined the effect of the GLP-1 RA...

Heart failure etiology impacts survival of patients with heart failure

DEFF Research Database (Denmark)

Pecini, Redi; Møller, Daniel Vega; Torp-Pedersen, Christian

2010-01-01

BACKGROUND: The impact of heart failure (HF) etiology on prognosis of HF is not well known. METHODS: 3078 patients (median age 75years, 61% male) hospitalized with HF were studied. Patients were classified into six etiology groups: hypertension (HTN, 13.9%), ischemic heart disease (IHD, 42...

Forkhead box transcription factors in embryonic heart development and congenital heart disease.

Science.gov (United States)

Zhu, Hong

2016-01-01

Embryonic heart development is a very complicated process regulated precisely by a network composed of many genes and signaling pathways in time and space. Forkhead box (Fox, FOX) proteins are a family of transcription factors characterized by the presence of an evolutionary conserved "forkhead"or "winged-helix" DNA-binding domain and able to organize temporal and spatial gene expression during development. They are involved in a wide variety of cellular processes, such as cell cycle progression, proliferation, differentiation, migration, metabolism and DNA damage response. An abundance of studies in model organisms and systems has established that Foxa2, Foxc1/c2, Foxh1 and Foxm1, Foxos and Foxps are important components of the signaling pathways that instruct cardiogenesis and embryonic heart development, playing paramount roles in heart development. The previous studies also have demonstrated that mutations in some of the forkhead box genes and the aberrant expression of forkhead box gene are heavily implicated in the congenital heart disease (CHD) of humans. This review primarily focuses on the current understanding of heart development regulated by forkhead box transcription factors and molecular genetic mechanisms by which forkhead box factors modulate heart development during embryogenesis and organogenesis. This review also summarizes human CHD related mutations in forkhead box genes as well as the abnormal expression of forkhead box gene, and discusses additional possible regulatory mechanisms of the forkhead box genes during embryonic heart development that warrant further investigation. Copyright © 2015 Elsevier Inc. All rights reserved.

Radioisotope heart examination during exercise to diagnose ischemic heart disease

International Nuclear Information System (INIS)

Farsky, S.

1986-01-01

The radioisotope exercise test is discussed and its benefits characterized for the diagnosis of ischemic heart disease, namely the use of 99m Tc in scintiscanning heart ventricles and of 201 Tl in scintiscanning myocardial perfusion. The exercise ventricular function and perfusion scintigraphies are compared with the common exercise ECG examination, and their superior sensitivity and specificity emphasized. Considering the constraints of scintigraphic imaging, indications are outlined for patients including those with suspect serious ischemic heart disease in whom the exercise ECG test has been negative or inconclusive, patients with the so-called nondiagnostic ECG, patients with atypical symptoms, and healthy individuals for whom the exercise ECG test indicated with respect to their occupation has been positive. Both radionuclide imaging techniques are complementary and are shown to be valuable not only in improving the diagnosis of ischemic heart disease but also in identifying the high-risk patients in whom cardiac surgery is to be considered. (L.O.)

Cardiac damage in athlete's heart: When the "supernormal" heart fails!

Science.gov (United States)

Carbone, Andreina; D'Andrea, Antonello; Riegler, Lucia; Scarafile, Raffaella; Pezzullo, Enrica; Martone, Francesca; America, Raffaella; Liccardo, Biagio; Galderisi, Maurizio; Bossone, Eduardo; Calabrò, Raffaele

2017-06-26

Intense exercise may cause heart remodeling to compensate increases in blood pressure or volume by increasing muscle mass. Cardiac changes do not involve only the left ventricle, but all heart chambers. Physiological cardiac modeling in athletes is associated with normal or enhanced cardiac function, but recent studies have documented decrements in left ventricular function during intense exercise and the release of cardiac markers of necrosis in athlete's blood of uncertain significance. Furthermore, cardiac remodeling may predispose athletes to heart disease and result in electrical remodeling, responsible for arrhythmias. Athlete's heart is a physiological condition and does not require a specific treatment. In some conditions, it is important to differentiate the physiological adaptations from pathological conditions, such as hypertrophic cardiomyopathy, arrhythmogenic dysplasia of the right ventricle, and non-compaction myocardium, for the greater risk of sudden cardiac death of these conditions. Moreover, some drugs and performance-enhancing drugs can cause structural alterations and arrhythmias, therefore, their use should be excluded.

CDC Vital Signs-Heart Age

Centers for Disease Control (CDC) Podcasts

2015-09-01

This podcast is based on the September 2015 CDC Vital Signs report. Your heart age is the age of your heart and blood vessels as a result of your risk factors for heart attack and stroke. If you smoke or have high blood pressure, your heart age will be much higher than your actual age. Learn what you can do to lower your heart age and keep it low.  Created: 9/1/2015 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 9/1/2015.

Taking radionuclides to heart

International Nuclear Information System (INIS)

Kleynhans, P.H.T.; Lotter, M.G.; Van Aswegen, A.; Minnaar, P.C.; Iturralde, M.; Herbst, C.P.; Marx, D.

1980-01-01

Ischaemic heart disease is a main cause of death in South Africa. Non-invasive ECG gated radionuclide bloodpool imaging plays an increasingly useful role in the evalution of the function of the heart as a pump, and the extent of heart muscle perfusion defects is further pinpointed by invasive krypton-81m studies to improve patient management

HeartCare+: A Smart Heart Care Mobile Application for Framingham-Based Early Risk Prediction of Hard Coronary Heart Diseases in Middle East

Directory of Open Access Journals (Sweden)

Hoda Ahmed Galal Elsayed

2017-01-01

Full Text Available Background. Healthcare is a challenging, yet so demanding sector that developing countries are paying more attention to recently. Statistics show that rural areas are expected to develop a high rate of heart diseases, which is a leading cause of sudden mortality, in the future. Thus, providing solutions that can assist rural people in detecting the cardiac risks early will be vital for uncovering and even preventing the long-term complications of cardiac diseases. Methodology. Mobile technology can be effectively utilized to limit the cardiac diseases’ prevalence in rural Middle East. This paper proposes a smart mobile solution for early risk detection of hard coronary heart diseases that uses the Framingham scoring model. Results. Smart HeartCare+ mobile app estimates accurately coronary heart diseases’ risk over 10 years based on clinical and nonclinical data and classifies the patient risk to low, moderate, or high. HeartCare+ also directs the patients to further treatment recommendations. Conclusion. This work attempts to investigate the effectiveness of the mobile technology in the early risk detection of coronary heart diseases. HeartCare+ app intensifies the communication channel between the lab workers and patients residing in rural areas and cardiologists and specialist residing in urban places.

Evaluation of Parameters Affecting Magnetic Abrasive Finishing on Concave Freeform Surface of Al Alloy via RSM Method

Directory of Open Access Journals (Sweden)

Mehrdad Vahdati

2016-01-01

Full Text Available The attempts of researchers in industries to obtain accurate and high quality surfaces led to the invention of new methods of finishing. Magnetic abrasive finishing (MAF is a relatively new type of finishing in which the magnetic field is used to control the abrasive tools. Applications such as the surface of molds are ones of the parts which require very high surface smoothness. Usually this type of parts has freeform surface. In this study, the effect of magnetic abrasive process parameters on freeform surfaces of parts made of aluminum is examined. This method is obtained through combination of magnetic abrasive process and Control Numerical Computer (CNC. The use of simple hemisphere for installation on the flat area of the magnets as well as magnets’ spark in curve form is a measure done during testing the experiments. The design of experiments is based on response surface methodology. The gap, the rotational speed of the spindle, and the feed rate are found influential and regression equations governing the process are also determined. The impact of intensity of the magnetic field is obtained using the finite element software of Maxwell. Results show that in concave areas of the surface, generally speaking, the surface roughness decreases to 0.2 μm from its initial 1.3 μm roughness. However, in some points the lowest surface roughness of 0.08 μm was measured.

Ischaemic heart disease

DEFF Research Database (Denmark)

Houlberg Hansen, Louise; Mikkelsen, Søren

2013-01-01

Purpose. Correct prehospital diagnosis of ischaemic heart disease (IHD) may accelerate and improve the treatment. We sought to evaluate the accuracy of prehospital diagnoses of ischemic heart diseases assigned by physicians. Methods. The Mobile Emergency Care Unit (MECU) in Odense, Denmark...

World Heart Day

Centers for Disease Control (CDC) Podcasts

2009-09-01

For World Heart Day, learn more about what heart-healthy steps you can take in the workplace.  Created: 9/1/2009 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 9/9/2009.

Heart rate response to breathing

DEFF Research Database (Denmark)

Mehlsen, J; Pagh, K; Nielsen, J S

1987-01-01

Heart rate responses to stepwise and periodic changes in lung volume were studied in seven young healthy males. Stepwise inspiration and expiration both resulted in an increase in heart rate followed by a rapid decrease in heart rate. The fastest heart rate was reached in 1.6 +/- 0.5 s and in 3.......6 +/- 1.4 s in response to inspiration and expiration, respectively (P less than 0.01). The slowest heart rate was reached in 4.8 +/- 1.0 s and in 7.6 +/- 1.9 s in response to inspiration and expiration, respectively (P less than 0.01). Following this biphasic change the heart rate returned to a steady...... level. The difference between the fastest and the slowest heart rates was significantly larger in response to inspiration (21.7 +/- 7.3 beats per minute) than in response to expiration (12.0 +/- 7.3 beats per minute; P less than 0.01). Periodic changes in lung volume were performed with frequencies from...

Summary of the 2015 International Paediatric Heart Failure Summit of Johns Hopkins All Children's Heart Institute.

Science.gov (United States)

Jacobs, Jeffrey P; Quintessenza, James A; Karl, Tom R; Asante-Korang, Alfred; Everett, Allen D; Collins, Susan B; Ramirez-Correa, Genaro A; Burns, Kristin M; Cohen, Mitchell; Colan, Steven D; Costello, John M; Daly, Kevin P; Franklin, Rodney C G; Fraser, Charles D; Hill, Kevin D; Huhta, James C; Kaushal, Sunjay; Law, Yuk M; Lipshultz, Steven E; Murphy, Anne M; Pasquali, Sara K; Payne, Mark R; Rossano, Joseph; Shirali, Girish; Ware, Stephanie M; Xu, Mingguo; Jacobs, Marshall L

2015-08-01

In the United States alone, ∼14,000 children are hospitalised annually with acute heart failure. The science and art of caring for these patients continues to evolve. The International Pediatric Heart Failure Summit of Johns Hopkins All Children's Heart Institute was held on February 4 and 5, 2015. The 2015 International Pediatric Heart Failure Summit of Johns Hopkins All Children's Heart Institute was funded through the Andrews/Daicoff Cardiovascular Program Endowment, a philanthropic collaboration between All Children's Hospital and the Morsani College of Medicine at the University of South Florida (USF). Sponsored by All Children's Hospital Andrews/Daicoff Cardiovascular Program, the International Pediatric Heart Failure Summit assembled leaders in clinical and scientific disciplines related to paediatric heart failure and created a multi-disciplinary "think-tank". The purpose of this manuscript is to summarise the lessons from the 2015 International Pediatric Heart Failure Summit of Johns Hopkins All Children's Heart Institute, to describe the "state of the art" of the treatment of paediatric cardiac failure, and to discuss future directions for research in the domain of paediatric cardiac failure.

Attitude of the Saudi community towards heart donation, transplantation, and artificial hearts.

Science.gov (United States)

AlHabeeb, Waleed; AlAyoubi, Fakhr; Tash, Adel; AlAhmari, Leenah; AlHabib, Khalid F

2017-07-01

To understand the attitudes of the Saudi population towards heart donation and transplantation. Methods: A survey using a questionnaire addressing attitudes towards organ transplantation and donation was conducted across 18 cities in Saudi Arabia between September 2015 and March 2016.  Results: A total of 1250 respondents participated in the survey. Of these, approximately 91% agree with the concept of organ transplantation but approximately 17% do not agree with the concept of heart transplantation; 42.4% of whom reject heart transplants for religious reasons. Only 43.6% of respondents expressed a willingness to donate their heart and approximately 58% would consent to the donation of a relative's organ after death. A total of 59.7% of respondents believe that organ donation is regulated and 31.8% fear that the doctors will not try hard enough to save their lives if they consent to organ donation. Approximately 77% believe the heart is removed while the donor is alive; although, the same proportion of respondents thought they knew what brain death meant. Conclusion: In general, the Saudi population seem to accept the concept of transplantation and are willing to donate, but still hold some reservations towards heart donation.

Mortality by Heart Failure and Ischemic Heart Disease in Brazil from 1996 to 2011

International Nuclear Information System (INIS)

Gaui, Eduardo Nagib; Oliveira, Gláucia Maria Moraes de; Klein, Carlos Henrique

2014-01-01

Circulatory system diseases are the first cause of death in Brazil. To analyze the evolution of mortality caused by heart failure, by ischemic heart diseases and by ill-defined causes, as well as their possible relations, in Brazil and in the geoeconomic regions of the country (North, Northeast, Center-West, South and Southeast), from 1996 to 2011. Data were obtained from DATASUS and death declaration records with codes I20 and I24 for acute ischemic diseases, I25 for chronic ischemic diseases, and I50 for heart failure, and codes in chapter XIII for ill-defined causes, according to geoeconomic regions of Brazil, from 1996 to 2011. Mortality rates due to heart failure declined in Brazil and its regions, except for the North and the Northeast. Mortality rates due to acute ischemic heart diseases increased in the North and Northeast regions, especially from 2005 on; they remained stable in the Center-West region; and decreased in the South and in the Southeast. Mortality due to chronic ischemic heart diseases decreased in Brazil and in the Center-West, South and Southeast regions, and had little variation in the North and in the Northeast. The highest mortality rates due to ill-defined causes occurred in the Northeast until 2005. Mortality due to heart failure is decreasing in Brazil and in all of its geoeconomic regions. The temporal evolution of mortality caused by ischemic heart diseases was similar to that of heart failure. The decreasing number of deaths due to ill-defined causes may represent the improvement in the quality of information about mortality in Brazil. The evolution of acute ischemic heart diseases ranged according to regions, being possibly confused with the differential evolution of ill-defined causes

Mortality by Heart Failure and Ischemic Heart Disease in Brazil from 1996 to 2011

Directory of Open Access Journals (Sweden)

Eduardo Nagib Gaui

2014-06-01

Full Text Available Background: Circulatory system diseases are the first cause of death in Brazil. Objective: To analyze the evolution of mortality caused by heart failure, by ischemic heart diseases and by ill-defined causes, as well as their possible relations, in Brazil and in the geoeconomic regions of the country (North, Northeast, Center-West, South and Southeast, from 1996 to 2011. Methods: Data were obtained from DATASUS and death declaration records with codes I20 and I24 for acute ischemic diseases, I25 for chronic ischemic diseases, and I50 for heart failure, and codes in chapter XIII for ill-defined causes, according to geoeconomic regions of Brazil, from 1996 to 2011. Results: Mortality rates due to heart failure declined in Brazil and its regions, except for the North and the Northeast. Mortality rates due to acute ischemic heart diseases increased in the North and Northeast regions, especially from 2005 on; they remained stable in the Center-West region; and decreased in the South and in the Southeast. Mortality due to chronic ischemic heart diseases decreased in Brazil and in the Center-West, South and Southeast regions, and had little variation in the North and in the Northeast. The highest mortality rates due to ill-defined causes occurred in the Northeast until 2005. Conclusions: Mortality due to heart failure is decreasing in Brazil and in all of its geoeconomic regions. The temporal evolution of mortality caused by ischemic heart diseases was similar to that of heart failure. The decreasing number of deaths due to ill-defined causes may represent the improvement in the quality of information about mortality in Brazil. The evolution of acute ischemic heart diseases ranged according to regions, being possibly confused with the differential evolution of ill-defined causes.

Mortality by Heart Failure and Ischemic Heart Disease in Brazil from 1996 to 2011

Energy Technology Data Exchange (ETDEWEB)

Gaui, Eduardo Nagib, E-mail: engaui@cardiol.br; Oliveira, Gláucia Maria Moraes de [Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Klein, Carlos Henrique [Escola Nacional de Saúde Pública Sérgio Arouca da Fundação Oswaldo Cruz, Rio de Janeiro, RJ (Brazil)

2014-06-15

Circulatory system diseases are the first cause of death in Brazil. To analyze the evolution of mortality caused by heart failure, by ischemic heart diseases and by ill-defined causes, as well as their possible relations, in Brazil and in the geoeconomic regions of the country (North, Northeast, Center-West, South and Southeast), from 1996 to 2011. Data were obtained from DATASUS and death declaration records with codes I20 and I24 for acute ischemic diseases, I25 for chronic ischemic diseases, and I50 for heart failure, and codes in chapter XIII for ill-defined causes, according to geoeconomic regions of Brazil, from 1996 to 2011. Mortality rates due to heart failure declined in Brazil and its regions, except for the North and the Northeast. Mortality rates due to acute ischemic heart diseases increased in the North and Northeast regions, especially from 2005 on; they remained stable in the Center-West region; and decreased in the South and in the Southeast. Mortality due to chronic ischemic heart diseases decreased in Brazil and in the Center-West, South and Southeast regions, and had little variation in the North and in the Northeast. The highest mortality rates due to ill-defined causes occurred in the Northeast until 2005. Mortality due to heart failure is decreasing in Brazil and in all of its geoeconomic regions. The temporal evolution of mortality caused by ischemic heart diseases was similar to that of heart failure. The decreasing number of deaths due to ill-defined causes may represent the improvement in the quality of information about mortality in Brazil. The evolution of acute ischemic heart diseases ranged according to regions, being possibly confused with the differential evolution of ill-defined causes.

Understand Your Risk for Heart Failure

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... Heart.org Arrhythmia About Arrhythmia Why Arrhythmia Matters Understand Your Risk for Arrhythmia Symptoms, Diagnosis & Monitoring of ... Heart Defects The Impact of Congenital Heart Defects Understand Your Risk for Congenital Heart Defects Symptoms & Diagnosis ...

What Is a Pediatric Heart Surgeon?

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... Text Size Email Print Share What is a Pediatric Heart Surgeon? Page Content Article Body If your ... require heart surgery. What Kind of Training Do Pediatric Heart Surgeons Have? Pediatric heart surgeons are medical ...

African-Americans and Heart Disease, Stroke

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... Research for Heart.org Educator for Heart.org CPR & ECC for Heart.org Shop for Heart.org ... controlled diabetes and suffered preventable complications such as blindness, amputations, or renal failure. For diabetes and other ...

Options for Heart Valve Replacement

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... Guide: Understanding Your Heart Valve Problem | Spanish Symptom Tracker | Spanish Pre-surgery Checklist | Spanish What Is Heart ... Cardiac Arrest: How Are They Different? 7 Warning Signs of a Heart Attack 8 Low Blood Pressure - ...

Heart transplantation for adults with congenital heart disease: current status and future prospects.

Science.gov (United States)

Matsuda, Hikaru; Ichikawa, Hajime; Ueno, Takayoshi; Sawa, Yoshiki

2017-06-01

Increased survival rates after corrective or palliative surgery for complex congenital heart disease (CHD) in infancy and childhood are now being coupled with increased numbers of patients who survive to adulthood with various residual lesions or sequelae. These patients are likely to deteriorate in cardiac function or end-organ function, eventually requiring lifesaving treatment including heart transplantation. Although early and late outcomes of heart transplantation have been improving for adult survivors of CHD, outcomes and pretransplant management could still be improved. Survivors of Fontan procedures are a vulnerable cohort, particularly when single ventricle physiology fails, mostly with protein-losing enteropathy and hepatic dysfunction. Therefore, we reviewed single-institution and larger database analyses of adults who underwent heart transplantation for CHD, to enable risk stratification by identifying the indications and outcomes. As the results, despite relatively high early mortality, long-term results were encouraging after heart transplantation. However, further investigations are needed to improve the indication criteria for complex CHD, especially for failed Fontan. In addition, the current system of status criteria and donor heart allocation system in heart transplantation should be arranged as suitable for adults with complex CHD. Furthermore, there is a strong need to develop ventricular assist devices as a bridge to transplantation or destination therapy, especially where right-sided circulatory support is needed.

Radiochemicals used to scan the heart

International Nuclear Information System (INIS)

Anon.

1975-01-01

Techniques for heart scanning using 201 Tl and /sup 99m/Tc pyrophosphate are discussed. Thallium-201, produced artificially in a cyclotron, concentrates in normal heart muscle but not in abnormal tissue. Technetium-99m is deposited in mitochondria of heart cells that are irreversibly damaged. The combined use of 201 Tl and /sup 99m/Tc makes it possible to identify regions of recent heart damage as well as older heart damage. Advantages of using 129 Cs for heart scanning are also discussed

Heart Disease in Hispanic Women

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... Heart Disease in Women Heart Disease in Hispanic Women “I thought it couldn’t be true,” says ... disease is their No. 1 killer. Why Hispanic women? While heart disease doesn’t discriminate, you could ...

Heart Disease and African Americans

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... Minority Population Profiles > Black/African American > Heart Disease Heart Disease and African Americans Although African American adults are ... were 30 percent more likely to die from heart disease than non-Hispanic whites. African American women are ...

Valvular Heart Disease.

Science.gov (United States)

Mrsic, Zorana; Hopkins, Scott P; Antevil, Jared L; Mullenix, Philip S

2018-03-01

This article outlines the diagnosis and management of commonly occurring valvular heart diseases for the primary care provider. Basic understanding of pathologic murmurs is important for appropriate referral. Echocardiography is the gold standard for diagnosis and severity grading. Patients with progressive valvular heart disease should be followed annually by cardiology and imaging should be performed based on the severity of valvular dysfunction. Surgery or intervention is recommended only when symptoms dictate or when changes in left ventricular function occur. Surgery or intervention should be performed after discussion by a heart team, including cardiologists and cardiac surgeons. Published by Elsevier Inc.

[Total artificial heart].

Science.gov (United States)

Antretter, H; Dumfarth, J; Höfer, D

2015-09-01

To date the CardioWest™ total artificial heart is the only clinically available implantable biventricular mechanical replacement for irreversible cardiac failure. This article presents the indications, contraindications, implantation procedere and postoperative treatment. In addition to a overview of the applications of the total artificial heart this article gives a brief presentation of the two patients treated in our department with the CardioWest™. The clinical course, postoperative rehabilitation, device-related complications and control mechanisms are presented. The total artificial heart is a reliable implant for treating critically ill patients with irreversible cardiogenic shock. A bridge to transplantation is feasible with excellent results.

Heart failure - fluids and diuretics

Science.gov (United States)

... this page: //medlineplus.gov/ency/patientinstructions/000112.htm Heart failure - fluids and diuretics To use the sharing features ... to Expect at Home When you have heart failure, your heart does not pump out enough blood. This causes ...

What is Broken Heart Syndrome

Science.gov (United States)

... pumping action and blood flow, go to the Health Topics How the Heart Works article.) Researchers are trying to identify the precise way in which the stress hormones affect the heart. Broken heart syndrome may result from ...

Exercise echocardiography for structural heart disease.

Science.gov (United States)

Izumo, Masaki; Akashi, Yoshihiro J

2016-03-01

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

The pathophysiology of heart failure.

Science.gov (United States)

Kemp, Clinton D; Conte, John V

2012-01-01

Heart failure is a clinical syndrome that results when the heart is unable to provide sufficient blood flow to meet metabolic requirements or accommodate systemic venous return. This common condition affects over 5 million people in the United States at a cost of $10-38 billion per year. Heart failure results from injury to the myocardium from a variety of causes including ischemic heart disease, hypertension, and diabetes. Less common etiologies include cardiomyopathies, valvular disease, myocarditis, infections, systemic toxins, and cardiotoxic drugs. As the heart fails, patients develop symptoms which include dyspnea from pulmonary congestion, and peripheral edema and ascites from impaired venous return. Constitutional symptoms such as nausea, lack of appetite, and fatigue are also common. There are several compensatory mechanisms that occur as the failing heart attempts to maintain adequate function. These include increasing cardiac output via the Frank-Starling mechanism, increasing ventricular volume and wall thickness through ventricular remodeling, and maintaining tissue perfusion with augmented mean arterial pressure through activation of neurohormonal systems. Although initially beneficial in the early stages of heart failure, all of these compensatory mechanisms eventually lead to a vicious cycle of worsening heart failure. Treatment strategies have been developed based upon the understanding of these compensatory mechanisms. Medical therapy includes diuresis, suppression of the overactive neurohormonal systems, and augmentation of contractility. Surgical options include ventricular resynchronization therapy, surgical ventricular remodeling, ventricular assist device implantation, and heart transplantation. Despite significant understanding of the underlying pathophysiological mechanisms in heart failure, this disease causes significant morbidity and carries a 50% 5-year mortality. Copyright © 2012 Elsevier Inc. All rights reserved.

Socioeconomic aspects of heart transplantation.

Science.gov (United States)

Evans, R W

1995-03-01

Heart transplantation is an established treatment modality for end-stage cardiac disease. Unfortunately, relative to other health care priorities, heart transplantation has fallen into disrepute. Efforts to reform the health care system have focused on three fundamental issues--cost, quality, and access. On each count, heart transplantation is vulnerable to criticism. Managed care is an incremental approach to health care reform that imposes fiscal constraint on providers. This constraint is expressed in the form of capitation which, in turn, requires providers to assume risk and accept economic responsibility for clinical decisions. While the need for transplantation is considerable, there are both clinical and economic factors limiting the overall level of activity. In 1993, over 2200 heart transplants were performed in the United States on people who were dying of end-stage cardiac disease. The total demand for heart transplantation was estimated to be about 5900 persons, which was not met due to an insufficient supply of donor hearts. Absent donors, the fiscal consequences of heart transplantation are minimized. In 1993, actuaries estimated that the total charge per heart transplant was $209,100. By designating centers based on price and quality considerations, managed care plans have reduced this per procedure expense to less than $100,000. While the benefits of transplantation are noteworthy, there are still concerns. Sixty percent of patients report that they are able to work, but only 30% do so. Employers hope to improve upon this record by expanding the designated center approach. In conclusion, the future of heart transplantation is unclear. Opportunities for innovation are limited, although the management of heart failure is an area of increased interest.

Biomarkers in acute heart failure.

Science.gov (United States)

Mallick, Aditi; Januzzi, James L

2015-06-01

The care of patients with acutely decompensated heart failure is being reshaped by the availability and understanding of several novel and emerging heart failure biomarkers. The gold standard biomarkers in heart failure are B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide, which play an important role in the diagnosis, prognosis, and management of acute decompensated heart failure. Novel biomarkers that are increasingly involved in the processes of myocardial injury, neurohormonal activation, and ventricular remodeling are showing promise in improving diagnosis and prognosis among patients with acute decompensated heart failure. These include midregional proatrial natriuretic peptide, soluble ST2, galectin-3, highly-sensitive troponin, and midregional proadrenomedullin. There has also been an emergence of biomarkers for evaluation of acute decompensated heart failure that assist in the differential diagnosis of dyspnea, such as procalcitonin (for identification of acute pneumonia), as well as markers that predict complications of acute decompensated heart failure, such as renal injury markers. In this article, we will review the pathophysiology and usefulness of established and emerging biomarkers for the clinical diagnosis, prognosis, and management of acute decompensated heart failure. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Six-Year Outcome of Subjects Without Overt Heart Disease With an Early Repolarization/J Wave Electrocardiographic Pattern.

Science.gov (United States)

Lanza, Gaetano Antonio; Argirò, Alessia; Mollo, Roberto; De Vita, Antonio; Spera, Francesco; Golino, Michele; Rota, Elisabetta; Filice, Monica; Crea, Filippo

2017-12-01

"Early repolarization" (ER) is a frequent finding at standard electrocardiogram (ECG). In this study we assessed whether ER is associated with an increased risk of events, as recently suggested by some studies. We prospectively enrolled 4,176 consecutive subjects without any heart disease who underwent routine ECG recording. ER was diagnosed in case of typical concave ST-segment elevation ≥0.1 mV; a J wave was diagnosed when the QRS showed a notch or a slur in its terminal part. In this study we compared the 6-year outcome of all 687 subjects with ER/J wave and 687 matched subjects without ER/J wave (controls). Both groups included 335 males and 352 females, and age was 48.8 ± 18 years. Overall, 145 deaths occurred (11%), only 11 of which attributed to cardiac causes. No sudden death was reported. Cardiac deaths occurred in 5 (0.8%) and 6 (0.9%) ER/J wave subjects and controls, respectively (odds ratio [OR] 0.85, 95% confidence interval [CI] 0.26 to 2.80, p = 0.79). Both ER (OR 1.68, 95% CI 0.21 to 13.3, p = 0.62) and J wave (OR 0.91, 95% CI 0.28 to 3.00, p = 0.88) showed no association with cardiac death. Total mortality was 11.5% in the ER/J wave group and 10.6% in the control group (OR 1.10, 95% CI 0.78 to 1.56, p = 0.58). Both ER (OR 0.44, 95% CI 0.16 to 1.24, p = 0.12) and J wave (OR 1.20, 95% CI 0.85 to 1.70, p = 0.30) showed also no association with all-cause death. In subjects without any evidence of heart disease, we found no significant association of ER/J wave with the risk of cardiac, as well as all-cause, death at medium-term follow-up. Copyright © 2017 Elsevier Inc. All rights reserved.

Your Heart Failure Healthcare Team

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... Artery Disease Venous Thromboembolism Aortic Aneurysm More Your Heart Failure Healthcare Team Updated:May 9,2017 Patients with ... to the Terms and Conditions and Privacy Policy Heart Failure • Home • About Heart Failure • Causes and Risks for ...

Planning Ahead: Advanced Heart Failure

Science.gov (United States)

... Venous Thromboembolism Aortic Aneurysm More Planning Ahead: Advanced Heart Failure Updated:May 9,2017 An important part of ... Care This content was last reviewed May 2017. Heart Failure • Home • About Heart Failure • Causes and Risks for ...

Effect of repeated tracheostomy tube reprocessing on biofilm formation.

Science.gov (United States)

Rodney, Jennifer; Ojano-Dirain, Carolyn P; Antonelli, Patrick J; Silva, Rodrigo C

2016-04-01

To determine the effect of repeated reprocessing of pediatric tracheostomy tubes (TTs) on biofilm formation. In vitro microbiological study. Pediatric, uncuffed, polyvinyl chloride (PVC) TTs from two different manufacturers (Tracoe Mini and Shiley) were reprocessed mechanically with household detergent and soaked in sodium hypochlorite (bleach). Two TTs of each brand were reprocessed 0 (control), 10, or 20 times. Twenty 2-mm coupons were then obtained from each TT, immersed in human mucus, and cultured with either Staphylococcus aureus or Pseudomonas aeruginosa. Biofilm formation was evaluated with bacterial counts. Bacterial counts of S. aureus for both brands were significantly higher on the TTs that were reprocessed 20 times compared to those that were not reprocessed (Tracoe: P = .040, Shiley: P  attachment. Further investigation is needed to determine the optimal technique and limits of reprocessing TTs in clinical practice. NA. Laryngoscope published by Wiley on behalf of the American Laryngological, Rhinological and Otological Society, Inc, “The Triological Society” and American Laryngological Association (the “Owner”).

What Is a Heart Transplant?

Science.gov (United States)

... risks. Primary graft dysfunction happens when the donor heart fails and cannot function. This is the most frequent ... heart’s arteries and cause the donor heart to fail. Over time, your new heart may fail due to the same reasons that ...

The Semantics of Heart: Translation Problems

Directory of Open Access Journals (Sweden)

Hortensia Pârlog

2005-06-01

Full Text Available Words hardly ever occur on their own, because they can hardly mean anything on their own, when asked about the meaning of an isolated word, in order to figure it out, what one does is try to place it in a context or use it in a collocation. The verbal contexts in which words appear influence or at least clarify their semantic value, it is because of contextual factors that a word may have more than one meaning. Therefore, the analysis above word level is extremely important. An analysis of translational decisions may also prove to be a valuable source of information in establishing the semantics of a lexical item. The above statements are illustrated by discussing the semantics of heart. The word occurs in a great number of structures in both English and Romanian, of which eight will be analysed: heart + verb, verb + heart, heart + of phrase, adjective + heart, heart + head noun, head noun +of heart, adjective + preposition + heart, heart in sayings or fixed expressions.

Alcohol and Heart Health

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... Check Recipe Certification Program Nutrition Requirements Heart-Check Professional Resources Contact the Heart-Check Certification Program Simple Cooking and Recipes Dining Out Choosing a Restaurant Deciphering ...

Caffeine and Heart Disease

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... Check Recipe Certification Program Nutrition Requirements Heart-Check Professional Resources Contact the Heart-Check Certification Program Simple Cooking and Recipes Dining Out Choosing a Restaurant Deciphering ...

Protein and Heart Health

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... Check Recipe Certification Program Nutrition Requirements Heart-Check Professional Resources Contact the Heart-Check Certification Program Simple Cooking and Recipes Dining Out Choosing a Restaurant Deciphering ...

Are two hearts better than one?

International Nuclear Information System (INIS)

Barton, H.; Cowie, A.; Kalff, V.; Richardson, M.; Kelly, M.J.

2000-01-01

Full text: Cardiac transplantation has become routine treatment, but not all available donor hearts can be matched. Heterotopic Cardiac Transplantation (the native heart remains in-situ), a technically difficult procedure, was introduced to partly address this limitation. Post-transplantation Gated Blood Pool Scans for these patients presented two challenges - finding the best angle for imaging the transplanted left ventricle, and distinguishing the ECG signals of the native and transplanted hearts. This allowed (a) observation of serial changes in LVEF of both hearts in seven patients, and (b) resolution of the controversy of what happens to native heart function. The transplanted heart was best imaged between LAO 5 deg and RAO 45 deg. By changing ECG limb lead positions or using a wandering V lead, it was usually possible to obtain an upright QRS complex for one heart and a downward complex for the other, allowing appropriate synchronisation of the ECG trigger. The transplant heart LVEF was obtained in 20/23 studies, being always 248%. Native LVEF was obtained in all cases where it was actively sought. Preliminary findings showed that, post-transplant, native LVEF (mean±SD) deteriorated in 6/6 patients (24%±12% to 9%±4%, p 0.95). One patient's native heart was in intermittent VT making him totally dependent on the transplanted heart. In conclusion this method allowed sequential follow-up of both hearts in these patients and demonstrated that native heart function deteriorates post-heterotopic transplant. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

The heart field effect: Synchronization of healer-subject heart rates in energy therapy.

Science.gov (United States)

Bair, Christine Caldwell

2008-01-01

Recent health research has focused on subtle energy and vibrational frequency as key components of health and healing. In particular, intentional direction of bioenergy is receiving increasing scientific attention. This study investigates the effect of the healer's electromagnetic (EM) heart field upon subjects during energy healing as measured by synchronization of heart rates and scores on a Subjective Units of Distress (SUD) scale and a Profile of Mood States (POMS) inventory. A nonequivalent pretest-posttest design was used based on heart rate comparisons between healer and subject and correlated with pre-and posttest SUD and POMS scores. Subjects included those who sat within the 3- to 4-foot "strong" range of the independent variable, the healer's heart field, while performing self-application of WHEE (the wholistic hybrid derived from EMDR [eye movement desensitization and reprocessing], and EFT [emotional freedom technique]), a meridian-based tapping technique (n=50); and those who performed the same process beyond the 15- to 18-foot range of the healer's EM heart field (n=41). The dependent variables were heart rate, SUD, and POMS inventory. All subjects completed these measures within 1 hour. Study results showed statistically significant heart-rate synchronization with the intervention population. In addition, SUD and POMS scores demonstrated considerably more improvement than in the control population, indicating additional benefit beyond the meridian-based therapies, such as WHEE, alone. Additional findings and future research recommendations are presented in this article.

Heart Health Tests: MedlinePlus Health Topic

Science.gov (United States)

... Heart Institute) Also in Spanish Heart-Health Screenings (American Heart Association) Picturing the Heart (National Institute of Biomedical Imaging and Bioengineering) Related Issues EKGs and Exercise Stress Tests: When You Need Them for Heart Disease - ...

Vitamin D and Heart Failure.

Science.gov (United States)

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

2017-10-01

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

Nutrition in Heart Failure

Directory of Open Access Journals (Sweden)

Reci Meseri

2013-10-01

Full Text Available Heart failure is defined as decreased ability of heart due to various reasons. It%u2019s seen 2-3% but the prevalence increases sharply after the age of seventy. The objectives of nutrition therapy in heart failure are to prevent from water retention and edema, to avoid from hard digestion and to offer a balanced diet. In order to avoid fluid retention and edema, daily sodium and fluid intake must be monitored carefully. Main dilemma of the heart failure patients is the obesity-cachexia dilemma. Since one of the main reasons of heart failure is cardiovascular diseases, in first phase, the patient may be obese. In the later phases, cachexia may show up. It was shown that cachexia is associated with mortality. Within this period, patients should not be over-fed and the patient should pass from catabolic state to anabolic state slowly. If the gastrointestinal track is functional oral/enteral feeding must be preferred. Multi vitamin and mineral supportsmay be beneficial, which may replace the increased loss, increase anti-inflammatory response and be anti-oxidants. Large, controlled and well-designed studies must be conducted in order to evaluate the benefits of nutritional practices such as nutritional assessment, enteral feeding and nutrient supports in heart failure patients.

Heart rate awareness in patients with chronic stable heart failure. A multi-center observational study.

LENUS (Irish Health Repository)

Moran, D

2014-08-23

We assessed adherence to European Society of Cardiology heart rate guidelines (i.e. heart rates less than 70bpm) in patients with chronic stable heart failure. We also investigated the percent of patients on target doses of rate controlling drugs.

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

Science.gov (United States)

Unkovic, Peter; Basuray, Anupam

2018-04-03

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

Heart rate variability analysis in healthy subjects, patients suffering from congestive heart failure and heart transplanted patients

Directory of Open Access Journals (Sweden)

Argentina Leite

2013-12-01

Full Text Available This study aimed to find parameters to characterize heart rate variability (HRV and discriminate healthy subjects and patients with heart diseases. The parameters used for discrimination characterize the different components of HRV memory (short and long and are extracted from HRV recordings using parametric as well as non parametric methods. Thus, the parameters are: spectral components at low frequencies (LH and high frequencies (HF which are associated with the short memory of HRV and the long memory parameter (d obtained from autoregressive fractionally integrated moving average (ARFIMA models. In the non parametric context, short memory (α1 and long memory (α2 parameters are obtained from detrended fluctuation analysis (DFA. The sample used in this study contains 24-hour Holter HRV recordings of 30 subjects: 10 healthy individuals, 10 patients suffering from congestive heart failure and 10 heart transplanted patients from the Noltisalis database. It was found that short memory parameters present higher values for the healthy individuals whereas long memory parameters present higher values for the diseased individuals. Moreover, there is evidence that ARFIMA modeling allows the discrimination between the 3 groups under study, being advantageous over DFA.

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

Science.gov (United States)

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

2015-01-01

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

Congenital Heart Defects and CCHD

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... and more. Stony Point, NY 10980 Close X Home > Complications & Loss > Birth defects & other health conditions > Congenital heart defects and ... in congenital heart defects. You have a family history of congenital heart ... syndrome or VCF. After birth Your baby may be tested for CCHD as ...

Malignant Tumors Of The Heart

International Nuclear Information System (INIS)

Dubrava, J.

2007-01-01

Autoptic prevalence of the heart tumors is 0,01 – 0,3 %. 12 – 25 % of them are malignant tumors and 75 – 88 % are benign. Malignancies are more frequently found in the right heart. Metastatic tumors occur 20 – 40-times more frequently than primary neoplasms. Even 94 % of primary malignant tumors are sarcomas. Most frequent of them are angio sarcomas. Heart metastases are only found in extensive dissemination. Highest prevalence of heart metastases is observed in melanoma, followed by malignant germ cell tumors, leukemia, lymphoma, lung cancer. The clinical presentation is due to the combination of heart failure, embolism, arrhythmias, pericardial effusion or tamponade. The symptoms depend on anatomical localization and the tumor size but not on the histological type. Prognosis of the heart malignancies is poor. Untreated patients die within several weeks to 2 years after the diagnosis was determined. Whenever possible the heart tumor should be resected, despite the surgery is usually neither definite nor sufficiently effective therapy. The patients with completely resectable sarcomas have better prognosis (median of survival 12 – 24 months) than the patients with incomplete resection (3 – 10 months). Complete excision is possible in only less than half of the patients. In some patients chemotherapy, radiotherapy, heart transplantation or combination of them prolonged the survival up to 2 years. Despite of this treatment median of the survival is only 1 year. (author)

Heart failure: epidemiology, pathophysiology, and management of heart failure in diabetes mellitus

OpenAIRE

Jorsal, Anders; Wiggers, Henrik; McMurray, John J.V.

2018-01-01

This article briefly discusses the epidemiology of heart failure and diabetes and summarizes the key findings from the recent cardiovascular outcome trials in patients with type 2 diabetes, with a focus on heart failure as an endpoint.

Syndecans in heart fibrosis.

Science.gov (United States)

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

2016-09-01

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

Congenital heart defects and extracardiac malformations.

Science.gov (United States)

Rosa, Rosana Cardoso M; Rosa, Rafael Fabiano M; Zen, Paulo Ricardo G; Paskulin, Giorgio Adriano

2013-06-01

To review the association between congenital heart defects and extracardiac malformations. Scientific articles were searched in the Medline, Lilacs, and SciELO databases, using the descriptors "congenital heart disease," "congenital heart defects," "congenital cardiac malformations," "extracardiac defects," and "extracardiac malformations." All case series that specifically explored the association between congenital heart defects and extracardiac malformations were included. Congenital heart diseases are responsible for about 40% of birth defects, being one of the most common and severe malformations. Extracardiac malformations are observed in 7 to 50% of the patients with congenital heart disease, bringing a greater risk of comorbidity and mortality and increasing the risks related to heart surgery. Different studies have attempted to assess the presence of extracardiac abnormalities in patients with congenital heart disease. Among the changes described, those of the urinary tract are more often reported. However, no study has evaluated all patients in the same way. Extracardiac abnormalities are frequent among patients with congenital heart disease, and patients with these alterations may present an increased risk of morbimortality. Therefore, some authors have been discussing the importance and cost-effectiveness of screening these children for other malformations by complementary exams.

Optimal Timing of Heart Transplant After HeartMate II Left Ventricular Assist Device Implantation.

Science.gov (United States)

Steffen, Robert J; Blackstone, Eugene H; Smedira, Nicholas G; Soltesz, Edward G; Hoercher, Katherine J; Thuita, Lucy; Starling, Randall C; Mountis, Maria; Moazami, Nader

2017-11-01

Optimal timing of heart transplantation in patients supported with second-generation left ventricular assist devices (LVADs) is unknown. Despite this, patients with LVADs continue to receive priority on the heart transplant waiting list. Our objective was to determine the optimal timing of transplantation for patients bridged with continuous-flow LVADs. A total of 301 HeartMate II LVADs (Thoratec Corp, Pleasanton, CA) were implanted in 285 patients from October 2004 to June 2013, and 86 patients underwent transplantation through the end of follow-up. Optimal transplantation timing was the product of surviving on LVAD support and surviving transplant. Three-year survival after both HeartMate II implantation and heart transplantation was unchanged when transplantation occurred within 9 months of implantation. Survival decreased as the duration of support exceeded this. Preoperative risk factors for death on HeartMate II support were prior valve operation, prior coronary artery bypass grafting, low albumin, low glomerular filtration rate, higher mean arterial pressure, hypertension, and earlier date of implant. Survival for patients without these risk factors was lowest when transplant was performed within 3 months but was relatively constant with increased duration of support. Longer duration of support was associated with poorer survival for patients with many of these risk factors. Device reimplantation, intracranial hemorrhage, and postimplant dialysis during HeartMate II support were associated with decreased survival. Survival of patients supported by the HeartMate II is affected by preoperative comorbidities and postoperative complications. Transplantation before complications is imperative in optimizing survival. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Nuclear cardiology and heart failure

International Nuclear Information System (INIS)

Giubbini, Raffaele; Bertagna, Francesco; Milan, Elisa; Mut, Fernando; Dondi, Maurizio; Metra, Marco; Rodella, Carlo

2009-01-01

The prevalence of heart failure in the adult population is increasing. It varies between 1% and 2%, although it mainly affects elderly people (6-10% of people over the age of 65 years will develop heart failure). The syndrome of heart failure arises as a consequence of an abnormality in cardiac structure, function, rhythm, or conduction. Coronary artery disease is the leading cause of heart failure and it accounts for this disorder in 60-70% of all patients affected. Nuclear techniques provide unique information on left ventricular function and perfusion by gated-single photon emission tomography (SPECT). Myocardial viability can be assessed by both SPECT and PET imaging. Finally, autonomic dysfunction has been shown to increase the risk of death in patients with heart disease and this may be applicable to all patients with cardiac disease regardless of aetiology. MIBG scanning has a very promising prognostic value in patients with heart failure. (orig.)

Valvular heart disease and anaesthesia.

Science.gov (United States)

Paul, Abhijit; Das, Sucharita

2017-09-01

Valvular heart disease presents as mixed spectrum lesion in healthcare settings in the third-world and developing countries. Rheumatic heart disease still forms the bulk of the aetiopathology of valve lesions. Mitral and aortic valve lesions top the list of valvular pathology. A thorough understanding of the pathophysiology of valvular heart disease is essential while planning anaesthesia and perioperative care for such patients. Meticulous use of optimal fluids, close monitoring of the changing haemodynamics and avoidance of situations that can cause major reduction of cardiac output and fluid shifts are mandatory to achieve good clinical outcome. We searched MEDLINE using combinations of the following: anaesthesia, aortic, mitral, regurgitation, stenosis and valvular heart disease. We also hand searched textbooks and articles on valvular heart disease and anaesthesia. This article mainly focuses on the understanding the pathophysiology of valvular heart disease in patients presenting for non-cardiac surgeries in secondary and tertiary care setting.

Nuclear cardiology and heart failure

Energy Technology Data Exchange (ETDEWEB)

Giubbini, Raffaele; Bertagna, Francesco [University of Brescia, Department of Nuclear Medicine, Brescia (Italy); Milan, Elisa [Ospedale Di Castelfranco Veneto, Nuclear Medicine Unit, Castelfranco Veneto (Italy); Mut, Fernando; Dondi, Maurizio [International Atomic Energy Agency, Nuclear Medicine Section, Division of Human Health, Vienna (Austria); Metra, Marco [University of Brescia, Department of Cardiology, Brescia (Italy); Rodella, Carlo [Health Physics Department, Spedali Civili di Brescia, Brescia (Italy)

2009-12-15

The prevalence of heart failure in the adult population is increasing. It varies between 1% and 2%, although it mainly affects elderly people (6-10% of people over the age of 65 years will develop heart failure). The syndrome of heart failure arises as a consequence of an abnormality in cardiac structure, function, rhythm, or conduction. Coronary artery disease is the leading cause of heart failure and it accounts for this disorder in 60-70% of all patients affected. Nuclear techniques provide unique information on left ventricular function and perfusion by gated-single photon emission tomography (SPECT). Myocardial viability can be assessed by both SPECT and PET imaging. Finally, autonomic dysfunction has been shown to increase the risk of death in patients with heart disease and this may be applicable to all patients with cardiac disease regardless of aetiology. MIBG scanning has a very promising prognostic value in patients with heart failure. (orig.)

Heart transplantation from older donors

Directory of Open Access Journals (Sweden)

V. N. Poptsov

2017-01-01

Full Text Available In the current situation of the shortage of suitable donor organs, heart transplantation from older donors is one of the ways to increase the performance of more heart transplants, particularly, in patients with urgent need of transplantation. While planning a heart transplantation from older donor one should consider increased risk of early cardiac allograft dysfunction, preexisting coronary artery disease, accelerated transplant vasculopathy which may adversely affect early and long-term survival of recipients. Subject to careful selection of donor–recipient pairs, effective prevention and treatment of early cardiac allograft dysfunction, pre-existing atherosclerosis and transplant vasculopathy the early and long-term survival of heart transplant recipients from older donors is comparable to heart transplantation from young donors.

Cardio MRI right heart assessment

International Nuclear Information System (INIS)

Genova, K.

2013-01-01

Full text: Introduction: In recent years, the evaluation of the function and morphology of the right heart caused increasing interest as right sided dysfunction is an important prognostic factor in many cardiovascular diseases. Modern MRI technique is the method of choice for precise assessment of the morphology and function of the right heart and is increasingly used in routine practice. What you will learn: Selecting appropriate techniques tailored to the morphology and function of right heart and conform to accepted standards is crucial for obtaining diagnostic imaging. This requires, as knowledge of the art of study, and diseases that assessment of right heart is key. The various techniques used and the specifics of the study protocol in the underlying disease leading to right dysfunction, consistent with standards and based on our experience will be presented. Discussion: The function of the right heart and in particular right sided function affects the prognosis of a number of cardiovascular diseases. Right sided morphology and function are assessed in terms of hemodynamic and prognostic significance in a number of heart and lung diseases. This enables clinicians to refine therapy, monitoring the effect of treatment and appropriate adjustment and precise timing invasive procedure or surgery. Knowing the capabilities and limitations of the method, combined with clinically - oriented approach are prerequisites for accurate and informative assessment of the right heart. Conclusion: Cardiac MRI is a method that allows precise , non-invasive and non- ionizing radiation morphological and functional assessment of the right heart, with the evaluation of the pulmonary circulation, which determines its key importance in conditions requiring assessment of right heart

Influence of diuretic therapy on the features of heart rhythm variability changes in chronic heart failure patients

Directory of Open Access Journals (Sweden)

K R Alyeva

2018-02-01

Full Text Available Aim. To study comparative influence of furosemide and torasemide on heart rhythm variability in patients with chronic heart failure of ischemic origin. Methods. The study included 48 patients (29 males and 19 females with ischemic heart disease complicated by chronic heart failure, NYHA functional classes II-IV. All patients were randomized into two groups: group 1 (25 patients received furosemide as diuretic therapy, and group 2 (23 patients received torasemide. All patient underwent clinical examination including assessment of complaints and physical examination, laboratory and instrumental tests (electrocardiography, echocardiography, 6-minute walk test, 24 Hour Holter ECG monitoring before and 30 days after starting diuretic therapy. Results. Against the background of one-month diuretic therapy, positive dynamics of clinical parameters was registered in both main groups of patients receiving both furosemide and torasemide. In furosemide group deterioration of heart rhythm variability was observed. Torasemide treatment resulted in considerable improvement of vegetative regulation of heart activity. Conclusion. Diuretic therapy with furosemide is characterized by changes of time and spectral parameters of vegetative regulation of heart rhythm towards strengthening of sympathetic and attenuation of parasympathetic influence; diuretic therapy with torasemide resulted in considerable improvement of heart rhythm variability parameters, attenuation of sympathetic and strengthening of parasympathetic influence on heart rhythm that provides additional cardioprotection in the treatment of patients with chronic heart failure of ischemic origin.

Congenital Heart Disease: Causes, Diagnosis, Symptoms, and Treatments.

Science.gov (United States)

Sun, RongRong; Liu, Min; Lu, Lei; Zheng, Yi; Zhang, Peiying

2015-07-01

The congenital heart disease includes abnormalities in heart structure that occur before birth. Such defects occur in the fetus while it is developing in the uterus during pregnancy. About 500,000 adults have congenital heart disease in USA (WebMD, Congenital heart defects medications, www.WebMD.com/heart-disease/tc/congenital-heart-defects-medications , 2014). 1 in every 100 children has defects in their heart due to genetic or chromosomal abnormalities, such as Down syndrome. The excessive alcohol consumption during pregnancy and use of medications, maternal viral infection, such as Rubella virus, measles (German), in the first trimester of pregnancy, all these are risk factors for congenital heart disease in children, and the risk increases if parent or sibling has a congenital heart defect. These are heart valves defects, atrial and ventricular septa defects, stenosis, the heart muscle abnormalities, and a hole inside wall of the heart which causes defect in blood circulation, heart failure, and eventual death. There are no particular symptoms of congenital heart disease, but shortness of breath and limited ability to do exercise, fatigue, abnormal sound of heart as heart murmur, which is diagnosed by a physician while listening to the heart beats. The echocardiogram or transesophageal echocardiogram, electrocardiogram, chest X-ray, cardiac catheterization, and MRI methods are used to detect congenital heart disease. Several medications are given depending on the severity of this disease, and catheter method and surgery are required for serious cases to repair heart valves or heart transplantation as in endocarditis. For genetic study, first DNA is extracted from blood followed by DNA sequence analysis and any defect in nucleotide sequence of DNA is determined. For congenital heart disease, genes in chromosome 1 show some defects in nucleotide sequence. In this review the causes, diagnosis, symptoms, and treatments of congenital heart disease are described.

Periodontitis in Chronic Heart Failure.

Science.gov (United States)

Fröhlich, Hanna; Herrmann, Kristina; Franke, Jennifer; Karimi, Alamara; Täger, Tobias; Cebola, Rita; Katus, Hugo A; Zugck, Christian; Frankenstein, Lutz

2016-08-01

Periodontal disease has been associated with an increased risk of cardiovascular events. The purpose of our study was to investigate whether a correlation between periodontitis and chronic heart failure exists, as well as the nature of the underlying cause. We enrolled 71 patients (mean age, 54 ± 13 yr; 56 men) who had stable chronic heart failure; all underwent complete cardiologic and dental evaluations. The periodontal screening index was used to quantify the degree of periodontal disease. We compared the findings to those in the general population with use of data from the 4th German Dental Health Survey. Gingivitis, moderate periodontitis, and severe periodontitis were present in 17 (24%), 17 (24%), and 37 (52%) patients, respectively. Severe periodontitis was more prevalent among chronic heart failure patients than in the general population. In contrast, moderate periodontitis was more prevalent in the general population (P periodontal disease was not associated with the cause of chronic heart failure or the severity of heart failure symptoms. Six-minute walking distance was the only independent predictor of severe periodontitis. Periodontal disease is highly prevalent in chronic heart failure patients regardless of the cause of heart failure. Prospective trials are warranted to clarify the causal relationship between both diseases.

Menopause and Heart Disease

Science.gov (United States)

... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Menopause and Heart Disease Updated:Jun 23,2017 Heart ... can become more evident after the onset of menopause. Menopause does not cause cardiovascular diseases . However, certain ...

Heart disease - risk factors

Science.gov (United States)

Heart disease - prevention; CVD - risk factors; Cardiovascular disease - risk factors; Coronary artery disease - risk factors; CAD - risk ... a certain health condition. Some risk factors for heart disease you cannot change, but some you can. ...

Genetics of Valvular Heart Disease

Science.gov (United States)

LaHaye, Stephanie; Lincoln, Joy

2015-01-01

Valvular heart disease is associated with significant morbidity and mortality and often the result of congenital malformations. However, the prevalence is increasing in adults not only because of the growing aging population, but also because of improvements in the medical and surgical care of children with congenital heart valve defects. The success of the Human Genome Project and major advances in genetic technologies, in combination with our increased understanding of heart valve development, has led to the discovery of numerous genetic contributors to heart valve disease. These have been uncovered using a variety of approaches including the examination of familial valve disease and genome-wide association studies to investigate sporadic cases. This review will discuss these findings and their implications in the treatment of valvular heart disease. PMID:24743897

Bisoprolol for congestive heart failure

DEFF Research Database (Denmark)

Rosenberg, J.; Gustafsson, F.

2008-01-01

Background: beta-Blockers are a cornerstone in the treatment of systolic heart failure treatment, but not all beta-blockers are effective or in this setting. Objective: To define the role of bisoprolol, a highly selective beta(1)-antagonist in congestive heart failure due to systolic dysfunction....... Methods: Using the keywords 'bisoprolol' and 'heart failure' PubMed and BIOSIS databases were searched for information regarding pharmacology and relevant randomised clinical trials. Supplementary publications were acquired by scrutinising reference lists of relevant papers. Additional information...... was obtained from the FDA website. Conclusion: Bisoprolol is an effective and well-tolerated first-line beta-blocker for patients with systolic heart failure. The knowledge is primarily based on study patients with moderate-to-severe heart failure from the three CIBIS trials Udgivelsesdato: 2008/2...

Heart Attack Payment - Hospital

Data.gov (United States)

U.S. Department of Health & Human Services — Payment for heart attack patients measure – provider data. This data set includes provider data for payments associated with a 30-day episode of care for heart...

Pulmonary arterial hypertension in adults born with a heart septal defect: the Euro Heart Survey on adult congenital heart disease

NARCIS (Netherlands)

Engelfriet, Peter M.; Duffels, Marielle G. J.; Möller, Thomas; Boersma, Eric; Tijssen, Jan G. P.; Thaulow, Erik; Gatzoulis, Michael A.; Mulder, Barbara J. M.

2007-01-01

AIM: To investigate the role of pulmonary arterial hypertension (PAH) in adult patients born with a cardiac septal defect, by assessing its prevalence and its relation with patient characteristics and outcome. METHODS AND RESULTS: From the database of the Euro Heart Survey on adult congenital heart

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

Science.gov (United States)

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

2015-02-01

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

Isoproterenol effects evaluated in heart slices of human and rat in comparison to rat heart in vivo

International Nuclear Information System (INIS)

Herrmann, Julia E.; Heale, Jason; Bieraugel, Mike; Ramos, Meg; Fisher, Robyn L.; Vickers, Alison E.M.

2014-01-01

Human response to isoproterenol induced cardiac injury was evaluated by gene and protein pathway changes in human heart slices, and compared to rat heart slices and rat heart in vivo. Isoproterenol (10 and 100 μM) altered human and rat heart slice markers of oxidative stress (ATP and GSH) at 24 h. In this in vivo rat study (0.5 mg/kg), serum troponin concentrations increased with lesion severity, minimal to mild necrosis at 24 and 48 h. In the rat and the human heart, isoproterenol altered pathways for apoptosis/necrosis, stress/energy, inflammation, and remodeling/fibrosis. The rat and human heart slices were in an apoptotic phase, while the in vivo rat heart exhibited necrosis histologically and further progression of tissue remodeling. In human heart slices genes for several heat shock 70 kD members were altered, indicative of stress to mitigate apoptosis. The stress response included alterations in energy utilization, fatty acid processing, and the up-regulation of inducible nitric oxide synthase, a marker of increased oxidative stress in both species. Inflammation markers linked with remodeling included IL-1α, Il-1β, IL-6 and TNFα in both species. Tissue remodeling changes in both species included increases in the TIMP proteins, inhibitors of matrix degradation, the gene/protein of IL-4 linked with cardiac fibrosis, and the gene Ccl7 a chemokine that induces collagen synthesis, and Reg3b a growth factor for cardiac repair. This study demonstrates that the initial human heart slice response to isoproterenol cardiac injury results in apoptosis, stress/energy status, inflammation and tissue remodeling at concentrations similar to that in rat heart slices. - Highlights: • Human response to isoproterenol induced cardiac injury evaluated in heart slices. • Isoproterenol altered apoptosis, energy, inflammation and remodeling pathways. • Human model verified by comparison to rat heart slices and rat heart in vivo. • Human and rat respond to isoproterenol

Reassessing guidelines for heart failure

Directory of Open Access Journals (Sweden)

Helmut Drexler

2004-03-01

Full Text Available Significant progress has been made in the last few years in the management of heart failure. In particular several trials have given significant results. It has become apparent that heart failure may be prevented in some patients by treatment of risk factors such as coronary artery disease. Experience with angiotensin-converting enzyme (ACE inhibitors has shown that the survival and symptomatic benefits do last in the long term, and confirm that they are the first-line treatment in heart failure. The results of a number of trials using the angiotensin receptor blockers (ARBs candesartan, valsartan and losartan are presented and discussed. There is also some experience now in the use of candesartan for patients with heart failure and preserved left ventricular systolic function. The COMET trial compared the β-blockers carvedilol and metoprolol tartrate, and suggests that there may be differences in clinical effect between β-blockers. The selective aldosterone receptor blocker eplerenone was evaluated in the EPHESUS trial in post-MI patients with signs of heart failure. Based on these clinical trials, heart failure guidelines are now being updated.

Insulin Signaling and Heart Failure

Science.gov (United States)

Riehle, Christian; Abel, E. Dale

2016-01-01

Heart failure is associated with generalized insulin resistance. Moreover, insulin resistant states such as type 2 diabetes and obesity increases the risk of heart failure even after adjusting for traditional risk factors. Insulin resistance or type 2 diabetes alters the systemic and neurohumoral milieu leading to changes in metabolism and signaling pathways in the heart that may contribute to myocardial dysfunction. In addition, changes in insulin signaling within cardiomyocytes develop in the failing heart. The changes range from activation of proximal insulin signaling pathways that may contribute to adverse left ventricular remodeling and mitochondrial dysfunction to repression of distal elements of insulin signaling pathways such as forkhead (FOXO) transcriptional signaling or glucose transport which may also impair cardiac metabolism, structure and function. This article will review the complexities of insulin signaling within the myocardium and ways in which these pathways are altered in heart failure or in conditions associated with generalized insulin resistance. The implications of these changes for therapeutic approaches to treating or preventing heart failure will be discussed. PMID:27034277

Generation of Antigen Microarrays to Screen for Autoantibodies in Heart Failure and Heart Transplantation.

Directory of Open Access Journals (Sweden)

Andrzej Chruscinski

Full Text Available Autoantibodies directed against endogenous proteins including contractile proteins and endothelial antigens are frequently detected in patients with heart failure and after heart transplantation. There is evidence that these autoantibodies contribute to cardiac dysfunction and correlate with clinical outcomes. Currently, autoantibodies are detected in patient sera using individual ELISA assays (one for each antigen. Thus, screening for many individual autoantibodies is laborious and consumes a large amount of patient sample. To better capture the broad-scale antibody reactivities that occur in heart failure and post-transplant, we developed a custom antigen microarray technique that can simultaneously measure IgM and IgG reactivities against 64 unique antigens using just five microliters of patient serum. We first demonstrated that our antigen microarray technique displayed enhanced sensitivity to detect autoantibodies compared to the traditional ELISA method. We then piloted this technique using two sets of samples that were obtained at our institution. In the first retrospective study, we profiled pre-transplant sera from 24 heart failure patients who subsequently received heart transplants. We identified 8 antibody reactivities that were higher in patients who developed cellular rejection (2 or more episodes of grade 2R rejection in first year after transplant as defined by revised criteria from the International Society for Heart and Lung Transplantation compared with those who did have not have rejection episodes. In a second retrospective study with 31 patients, we identified 7 IgM reactivities that were higher in heart transplant recipients who developed antibody-mediated rejection (AMR compared with control recipients, and in time course studies, these reactivities appeared prior to overt graft dysfunction. In conclusion, we demonstrated that the autoantibody microarray technique outperforms traditional ELISAs as it uses less patient

Influence of heart failure on nucleolar organization and protein expression in human hearts

International Nuclear Information System (INIS)

Roselló-Lletí, Esther; Rivera, Miguel; Cortés, Raquel; Azorín, Inmaculada; Sirera, Rafael; Martínez-Dolz, Luis; Hove, Leif; Cinca, Juan; Lago, Francisca; González-Juanatey, José R.; Salvador, Antonio; Portolés, Manuel

2012-01-01

Highlights: ► Heart failure alters nucleolar morphology and organization. ► Nucleolin expression is significant increased in ischemic and dilated cardiomyopathy. ► Ventricular function of heart failure patients was related with nucleolin levels. -- Abstract: We investigate for the first time the influence of heart failure (HF) on nucleolar organization and proteins in patients with ischemic (ICM) or dilated cardiomyopathy (DCM). A total of 71 human hearts from ICM (n = 38) and DCM (n = 27) patients, undergoing heart transplantation and control donors (n = 6), were analysed by western-blotting, RT-PCR and cell biology methods. When we compared protein levels according to HF etiology, nucleolin was increased in both ICM (117%, p < 0.05) and DCM (141%, p < 0.01). Moreover, mRNA expression were also upregulated in ICM (1.46-fold, p < 0.05) and DCM (1.70-fold, p < 0.05. Immunofluorescence studies showed that the highest intensity of nucleolin was into nucleolus (p < 0.0001), and it was increased in pathological hearts (p < 0.0001). Ultrastructure analysis by electron microscopy showed an increase in the nucleus and nucleolus size in ICM (17%, p < 0.05 and 131%, p < 0.001) and DCM (56%, p < 0.01 and 69%, p < 0.01). Nucleolar organization was influenced by HF irrespective of etiology, increasing fibrillar centers (p < 0.001), perinucleolar chromatin (p < 0.01) and dense fibrillar components (p < 0.01). Finally, left ventricular function parameters were related with nucleolin levels in ischemic hearts (p < 0.0001). The present study demonstrates that HF influences on morphology and organization of nucleolar components, revealing changes in the expression and in the levels of nucleolin protein.

HEART OF MYTH - HEART OF SCIENCE Part I: Harriet Martineau's cardiac symptoms: a Victorian case history.

Science.gov (United States)

Bound Alberti, Fay

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

Insomnia Self-Management in Heart Failure

Science.gov (United States)

2018-01-05

Cardiac Failure; Heart Failure; Congestive Heart Failure; Heart Failure, Congestive; Sleep Initiation and Maintenance Disorders; Chronic Insomnia; Disorders of Initiating and Maintaining Sleep; Fatigue; Pain; Depressive Symptoms; Sleep Disorders; Anxiety

Heart Attack Payment - National

Data.gov (United States)

U.S. Department of Health & Human Services — Payment for heart attack patients measure – national data. This data set includes national-level data for payments associated with a 30-day episode of care for heart...

Heart Attack Payment - State

Data.gov (United States)

U.S. Department of Health & Human Services — Payment for heart attack patients measure – state data. This data set includes state-level data for payments associated with a 30-day episode of care for heart...

Inflammation and Heart Disease

Science.gov (United States)

... Disease Venous Thromboembolism Aortic Aneurysm More Inflammation and Heart Disease Updated:Jun 13,2017 Understand the risks of ... inflammation causes cardiovascular disease, inflammation is common for heart disease and stroke patients and is thought to be ...

Aspirin and heart disease

Science.gov (United States)

... medlineplus.gov/ency/patientinstructions/000092.htm Aspirin and heart disease To use the sharing features on this page, ... healthy people who are at low risk for heart disease. You provider will consider your overall medical condition ...

Deterministic Approach to Detect Heart Sound Irregularities

Directory of Open Access Journals (Sweden)

Richard Mengko

2017-07-01

Full Text Available A new method to detect heart sound that does not require machine learning is proposed. The heart sound is a time series event which is generated by the heart mechanical system. From the analysis of heart sound S-transform and the understanding of how heart works, it can be deducted that each heart sound component has unique properties in terms of timing, frequency, and amplitude. Based on these facts, a deterministic method can be designed to identify each heart sound components. The recorded heart sound then can be printed with each component correctly labeled. This greatly help the physician to diagnose the heart problem. The result shows that most known heart sounds were successfully detected. There are some murmur cases where the detection failed. This can be improved by adding more heuristics including setting some initial parameters such as noise threshold accurately, taking into account the recording equipment and also the environmental condition. It is expected that this method can be integrated into an electronic stethoscope biomedical system.

Valvular Disorders in Carcinoid Heart Disease

Directory of Open Access Journals (Sweden)

Shi-Min Yuan

Full Text Available Abstract Carcinoid heart disease is a rare but important cause of intrinsic right heart valve disorders leading to right heart failure. Occasionally, left-sided heart valves may also be involved. The characteristic cardiac pathological findings of carcinoid heart disease are endocardial thickening as a result of fibrous deposits on the endocardium. Echocardiographic examination and right heart catheterization are very useful for the diagnosis of the lesion. If more cardiac valves are affected, multiple valve replacement should be considered. The management of the pulmonary valve lesion depends on the extent of the diseased valve, either by valvulotomy, valvectomy, or valve replacement. Percutaneous valve implantations in the pulmonary and in the inferior vena cava positions have been advocated for high-risk patients.

Efficacy of trimetazidine combining with metoprolol on plasma BNP in coronary heart disease patients with heart failure

Directory of Open Access Journals (Sweden)

Ping Li

2016-01-01

Full Text Available Objective: To explore the effect of combined application of trimetazidine and metoprolol on plasma BNP in coronary heart disease patients with heart failure and the clinical efficacy. Methods: A total of 140 cases of coronary heart disease patients with heart failure treated in Cardiology Department of our hospital from May 2012 to January 2015 were selected and divided into study group and control group by random number table method. The control group received digitalis, diuretics, ACEI (angiotensin-converting enzyme inhibitor and other conventional drugs for treatment, the study group received combined use of trimetazidine and metoprolol on the basis of routine treatment of the control group, and treatment duration was 12 weeks. Then plasma BNP, systolic blood pressure, heart rate, left ventricular end diastolic diameter (LVEDD, left ventricular end systolic end (LVESD and left ventricular ejection fraction (LVEF of two groups before and after treatment were statistically analyzed, and the overall effect was evaluated. Results: Before treatment, there were no significant differences in plasma BNP, blood pressure, heart rate, LVEDD, LVESD and LVEF between the two groups; after treatment, plasma BNP, blood pressure, heart rate, LVEDD and LVESD of both groups decreased and LVEF increased, but the changes in study group were better than those in control group. Conclusion: Trimetazidine combined with metoprolol has better application effect in plasma BNP decrease and heart function improvement in coronary heart disease patients with heart failure.

Heart disease and women

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/007188.htm Heart disease and women To use the sharing features on ... please enable JavaScript. People often DO NOT consider heart disease a woman's disease. Yet cardiovascular disease is the ...

Machines versus medication for biventricular heart failure: focus on the total artificial heart.

Science.gov (United States)

Arabia, Francisco A; Moriguchi, Jaime D

2014-09-01

The medical/surgical management of advanced heart failure has evolved rapidly over the last few decades. With better understanding of heart failure pathophysiology, new pharmacological agents have been introduced that have resulted in improvements in survival. For those patients that fail to improve, mechanical circulatory support with left ventricular assist devices and total artificial hearts (TAHs) have served as a beneficial bridge to transplantation. The TAH has continued to play a significant role as a bridge to transplantation in patients with biventricular failure and more selected indications that could not be completely helped with left ventricular assist devices. Improved survival with the TAH has resulted in more patients benefiting from this technology. Improvements will eventually lead to a totally implantable device that will permanently replace the failing human heart.

Mapping the Heart

Science.gov (United States)

Hulse, Grace

2012-01-01

In this article, the author describes how her fourth graders made ceramic heart maps. The impetus for this project came from reading "My Map Book" by Sara Fanelli. This book is a collection of quirky, hand-drawn and collaged maps that diagram a child's world. There are maps of her stomach, her day, her family, and her heart, among others. The…

Radiation-induced heart injury. Radiopathological study

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Y; Niibe, H [Gunma Univ., Maebashi (Japan). School of Medicine

1975-11-01

In order to identify radiation-induced heart injury and to differentiate it from heart disease, an attempt was made to clarify post-irradiation heart injury by investigating the histological changes which occur during the interval between the irradiation and the time of demonstrable histological changes. A study was made of 83 autopsies in which most of the primary neoplasms were breast cancers, lung cancers and mediastinal tumors. In 43 of these autopsies the heart had been irradiated. Sixty eight dd-strain mice were also used for microautoradiographic study. Histological changes in the heart were observed in 27 of the 43 cases receiving irradiation. The limit of the tolerance dose to the heart for indicating histological changes was 1220 ret in humans. The latent period without histological changes was 2.7 months after initiation of radiation therapy. Greater heart injury was observed after re-irradiation or after the combined therapy of radiation and chemotherapy especially mitomycin (MMC). The histological findings after treatment with MMC were similar to those of radiation-induced heart injury. Results of the study indicate that the damage is secondary to radiation-induced changes of the vascula connective tissue.

The Relation of Heart and Mind in The Asian Societies Reasoning heart: The Case of Yunus Emre

OpenAIRE

ÇETİNKAYA, BAYRAM ALİ

2018-01-01

This article, considers thatthe relation of heart and mind in the Asian Societies. Theheart as the center of ıntuition and the mind as the emperor of the castle of body. YunusEmre describes the heart as “the throne of God” whereas he refers to heart as the center ofthe Divine Light, mysteries, the wisdom and knowledge. Whereas the mind is the emperorof the castle of body, the heart is like a treasure between the mind and the body. Thistreasure opens up with the power of love. When the heart i...

General Concepts in Adult Congenital Heart Disease.

Science.gov (United States)

Mutluer, Ferit Onur; Çeliker, Alpay

2018-01-20

Congenital heart disease in adults (adult congenital heart disease) is a growing burden for healthcare systems. While infant mortality due to congenital heart disease in the last four decades decreased by almost 3-fold, adult congenital heart disease prevalence increased by more than 2-fold in United States. Adult congenital heart disease prevalence is expected to increase steadily until 2050 in projections. Adult congenital heart disease is a multifaceted problem with many dimensions. This manuscript aims to provide an overview of the common adult congenital heart diseases and summarize important points in management of these diseases with possible problems and complications that the patients and the physicians face.

General Concepts in Adult Congenital Heart Disease

Directory of Open Access Journals (Sweden)

Ferit Onur Mutluer

2018-02-01

Full Text Available Congenital heart disease in adults (adult congenital heart disease is a growing burden for healthcare systems. While infant mortality due to congenital heart disease in the last four decades decreased by almost 3-fold, adult congenital heart disease prevalence increased by more than 2-fold in United States. Adult congenital heart disease prevalence is expected to increase steadily until 2050 in projections. Adult congenital heart disease is a multifaceted problem with many dimensions. This manuscript aims to provide an overview of the common adult congenital heart diseases and summarize important points in management of these diseases with possible problems and complications that the patients and the physicians face

Outcome of patients undergoing open heart surgery at the Uganda heart institute, Mulago hospital complex.

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Aliku, Twalib O; Lubega, Sulaiman; Lwabi, Peter; Oketcho, Michael; Omagino, John O; Mwambu, Tom

2014-12-01

Heart disease is a disabling condition and necessary surgical intervention is often lacking in many developing countries. Training of the superspecialties abroad is largely limited to observation with little or no opportunity for hands on experience. An approach in which open heart surgeries are conducted locally by visiting teams enabling skills transfer to the local team and helps build to build capacity has been adopted at the Uganda Heart Institute (UHI). We reviewed the progress of open heart surgery at the UHI and evaluated the postoperative outcomes and challenges faced in conducting open heart surgery in a developing country. Medical records of patients undergoing open heart surgery at the UHI from October 2007 to June 2012 were reviewed. A total of 124 patients underwent open heart surgery during the study period. The commonest conditions were: venticular septal defects (VSDs) 34.7% (43/124), Atrial septal defects (ASDs) 34.7% (43/124) and tetralogy of fallot (TOF) in 10.5% (13/124). Non governmental organizations (NGOs) funded 96.8% (120/124) of the operations, and in only 4 patients (3.2%) families paid for the surgeries. There was increasing complexity in cases operated upon from predominantly ASDs and VSDs at the beginning to more complex cases like TOFs and TAPVR. The local team independently operated 19 patients (15.3%). Postoperative morbidity was low with arrhythmias, left ventricular dysfunction and re-operations being the commonest seen. Post operative sepsis occurred in only 2 cases (1.6%). The overall mortality rate was 3.2. Open heart surgery though expensive is feasible in a developing country. With increased direct funding from governments and local charities to support open heart surgeries, more cardiac patients access surgical treatment locally.

Air Quality and Heart Health: An Emerging Topic for Heart ...

Science.gov (United States)

Air Quality and Heart Health: An Emerging Topic for Heart Month: Ambient air particle pollution increases short- and long-term cardiovascular morbidity and mortality. Older-people, those with pre-existing heart disease and lung disease and diabetes are at higher risk. Mechanisms are under investigation and are likely related to oxidative stress, inflammation and effects on autonomic control. Improvements in air pollution levels reduce health impacts and increase life expectancy. Reductions of short-term exposure in those at highest risk are predicted to mitigate adverse health effects. EPA regularly evaluates the standards, health risks and issues improved standards when needed. Public health action is needed along with EPA standards to reduce the public health burden of short- and long-term adverse health effects of air pollution. Health risks remain and need to be addressed through integrated efforts of public health, health care, environmental health, individuals and communities. Presented at Webinar for the National Association of Clean Air Agencies, February 2, 2017, Chapel Hill, NC- This webinar provided an update of environmental health information related to the effects of air pollution and heart and blood vessel disease. Such information is critically important for the Clean Air Agencies to understand as it provides the justification of their actions.

The heart and hypothyroidism

African Journals Online (AJOL)

1983-04-09

Apr 9, 1983 ... influenced by the thyroid disorder and vice versa. We recenrly ... hypothyroidism is a rare cause of heart failure other causes of heart failure must be excluded ... signs of cardiac tamponade and echocardiographic features of a.

Heart disease and intimacy

Science.gov (United States)

... this page: //medlineplus.gov/ency/patientinstructions/000540.htm Heart disease and intimacy To use the sharing features on ... Libby P, Bonow RO, Braunwald E, eds. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine . 10th ed. Philadelphia, ...

Optimizing risk stratification in heart failure and the selection of candidates for heart transplantation.

Science.gov (United States)

Pereira-da-Silva, Tiago; M Soares, Rui; Papoila, Ana Luísa; Pinto, Iola; Feliciano, Joana; Almeida-Morais, Luís; Abreu, Ana; Cruz Ferreira, Rui

2018-02-01

Selecting patients for heart transplantation is challenging. We aimed to identify the most important risk predictors in heart failure and an approach to optimize the selection of candidates for heart transplantation. Ambulatory patients followed in our center with symptomatic heart failure and left ventricular ejection fraction ≤40% prospectively underwent a comprehensive baseline assessment including clinical, laboratory, electrocardiographic, echocardiographic, and cardiopulmonary exercise testing parameters. All patients were followed for 60 months. The combined endpoint was cardiac death, urgent heart transplantation or need for mechanical circulatory support, up to 36 months. In the 263 enrolled patients (75% male, age 54±12 years), 54 events occurred. The independent predictors of adverse outcome were ventilatory efficiency (VE/VCO 2 ) slope (HR 1.14, 95% CI 1.11-1.18), creatinine level (HR 2.23, 95% CI 1.14-4.36), and left ventricular ejection fraction (HR 0.96, 95% CI 0.93-0.99). VE/VCO 2 slope was the most accurate risk predictor at any follow-up time analyzed (up to 60 months). The threshold of 39.0 yielded high specificity (97%), discriminated a worse or better prognosis than that reported for post-heart transplantation, and outperformed peak oxygen consumption thresholds of 10.0 or 12.0 ml/kg/min. For low-risk patients (VE/VCO 2 slope <39.0), sodium and creatinine levels and variations in end-tidal carbon dioxide partial pressure on exercise identified those with excellent prognosis. VE/VCO 2 slope was the most accurate parameter for risk stratification in patients with heart failure and reduced ejection fraction. Those with VE/VCO 2 slope ≥39.0 may benefit from heart transplantation. Copyright © 2018 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

MIBG scintigraphy of the heart

International Nuclear Information System (INIS)

Hacker, M.; Weiss, M.

2009-01-01

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

Artificial heart for humanoid robot

Science.gov (United States)

Potnuru, Akshay; Wu, Lianjun; Tadesse, Yonas

2014-03-01

A soft robotic device inspired by the pumping action of a biological heart is presented in this study. Developing artificial heart to a humanoid robot enables us to make a better biomedical device for ultimate use in humans. As technology continues to become more advanced, the methods in which we implement high performance and biomimetic artificial organs is getting nearer each day. In this paper, we present the design and development of a soft artificial heart that can be used in a humanoid robot and simulate the functions of a human heart using shape memory alloy technology. The robotic heart is designed to pump a blood-like fluid to parts of the robot such as the face to simulate someone blushing or when someone is angry by the use of elastomeric substrates and certain features for the transport of fluids.

When Your Child Needs a Heart Transplant

Science.gov (United States)

... transplant. Why Do Kids Need Heart Transplants? A child's heart might not work right for many reasons. Sometimes, babies are born with heart defects (malformations) that cause their hearts to fail. These defects are the ...

Heart Transplant and Mechanical Circulatory Support in Patients With Advanced Heart Failure.

Science.gov (United States)

Sánchez-Enrique, Cristina; Jorde, Ulrich P; González-Costello, José

2017-05-01

Patients with advanced heart failure have a poor prognosis and heart transplant is still the best treatment option. However, the scarcity of donors, long waiting times, and an increasing number of unstable patients have favored the development of mechanical circulatory support. This review summarizes the indications for heart transplant, candidate evaluation, current immunosuppression strategies, the evaluation and treatment of rejection, infectious prophylaxis, and short and long-term outcomes. Regarding mechanical circulatory support, we distinguish between short- and long-term support and the distinct strategies that can be used: bridge to decision, recovery, candidacy, transplant, and destination therapy. We then discuss indications, risk assessment, management of complications, especially with long-term support, and outcomes. Finally, we discuss future challenges and how the widespread use of long-term support for patients with advanced heart failure will only be viable if their complications and costs are reduced. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Emerging Research Directions in Adult Congenital Heart Disease: A Report from a National Heart, Lung, and Blood Institute/Adult Congenital Heart Association Working Group

Science.gov (United States)

Gurvitz, Michelle; Burns, Kristin M.; Brindis, Ralph; Broberg, Craig S.; Daniels, Curt J.; Fuller, Stephanie M.P.N.; Honein, Margaret A.; Khairy, Paul; Kuehl, Karen S.; Landzberg, Michael J.; Mahle, William T.; Mann, Douglas L.; Marelli, Ariane; Newburger, Jane W.; Pearson, Gail D.; Starling, Randall C.; Tringali, Glenn R.; Valente, Anne Marie; Wu, Joseph C.; Califf, Robert M.

2016-01-01

Congenital heart disease (CHD) is the most common birth defect, affecting about 0.8% of live births. Advances in recent decades have allowed >85% of children with CHD to survive to adulthood, creating a growing population of adults with CHD. Little information exists regarding survival, demographics, late outcomes, and comorbidities in this emerging group, and multiple barriers impede research in adult CHD (ACHD). The National Heart, Lung, and Blood Institute and the Adult Congenital Heart Association convened a multidisciplinary Working Group to identify high-impact research questions in ACHD. This report summarizes the meeting discussions in the broad areas of CHD-related heart failure, vascular disease and multisystem complications. High-priority subtopics identified included heart failure in tetralogy of Fallot, mechanical circulatory support/transplantation, sudden cardiac death, vascular outcomes in coarctation of the aorta, late outcomes in single ventricle disease, cognitive and psychiatric issues, and pregnancy. PMID:27102511

Heart Disease Affects Women of All Ages

Science.gov (United States)

Skip Navigation Bar Home Current Issue Past Issues Heart Disease Affects Women of All Ages Past Issues / Winter ... weeks of a heart attack. For Women with Heart Disease: About 6 million American women have coronary heart ...

X-ray picture of the heart turn in echocardiographic diagnosis of rheumatic heart disease

International Nuclear Information System (INIS)

Grishkevich, A.M.; Goryanina, N.K.

1986-01-01

The paper is concerned with X-ray and echocardiographic investigation of the heart in 461 patients with mitral-tricuspidal disease. In 377 (82%) cases a turn of the heart along the longitudinal axis (counter clockwise) to the left and back was revealed. X-ray recognition of the heart turn made it possible to set an echocardiographic sensor to spot some of the cardiac cavities, interventricular septum and valvular apparatus. The correct setting of the echocardiographic sensor resulted in the determination of true sizes of each cardiac cavity, diagnosis of the nature of each valvular lesion and the recognition of such complications of rheumatic heart diseases as valvular calcinosis, left atrial thrombosis and disorder of myocardial contractility

Reduced Dietary Sodium Intake Increases Heart Rate

DEFF Research Database (Denmark)

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

2016-01-01

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

Influence of heart failure on nucleolar organization and protein expression in human hearts

Energy Technology Data Exchange (ETDEWEB)

Rosello-Lleti, Esther; Rivera, Miguel; Cortes, Raquel [Cardiocirculatory Unit, Research Center, Hospital Universitario La Fe, Valencia (Spain); Azorin, Inmaculada [Experimental Neurology, Research Center, Hospital Universitario La Fe, Valencia (Spain); Sirera, Rafael [Biotechnology Department, Universidad Politecnica, Valencia (Spain); Martinez-Dolz, Luis [Cardiology Unit, Hospital Universitario La Fe, Valencia (Spain); Hove, Leif; Cinca, Juan [Cardiology Unit, Hospital San Pau, Barcelona (Spain); Lago, Francisca; Gonzalez-Juanatey, Jose R. [Cardiology Unit, Institute of Biomedical Research, Hospital Clinicode Santiagode Compostela (Spain); Salvador, Antonio [Experimental Neurology, Research Center, Hospital Universitario La Fe, Valencia (Spain); Portoles, Manuel, E-mail: portoles_man@gva.es [Cell Biology and Pathology Unit, Research Center, Hospital Universitario La Fe, Valencia (Spain)

2012-02-10

Highlights: Black-Right-Pointing-Pointer Heart failure alters nucleolar morphology and organization. Black-Right-Pointing-Pointer Nucleolin expression is significant increased in ischemic and dilated cardiomyopathy. Black-Right-Pointing-Pointer Ventricular function of heart failure patients was related with nucleolin levels. -- Abstract: We investigate for the first time the influence of heart failure (HF) on nucleolar organization and proteins in patients with ischemic (ICM) or dilated cardiomyopathy (DCM). A total of 71 human hearts from ICM (n = 38) and DCM (n = 27) patients, undergoing heart transplantation and control donors (n = 6), were analysed by western-blotting, RT-PCR and cell biology methods. When we compared protein levels according to HF etiology, nucleolin was increased in both ICM (117%, p < 0.05) and DCM (141%, p < 0.01). Moreover, mRNA expression were also upregulated in ICM (1.46-fold, p < 0.05) and DCM (1.70-fold, p < 0.05. Immunofluorescence studies showed that the highest intensity of nucleolin was into nucleolus (p < 0.0001), and it was increased in pathological hearts (p < 0.0001). Ultrastructure analysis by electron microscopy showed an increase in the nucleus and nucleolus size in ICM (17%, p < 0.05 and 131%, p < 0.001) and DCM (56%, p < 0.01 and 69%, p < 0.01). Nucleolar organization was influenced by HF irrespective of etiology, increasing fibrillar centers (p < 0.001), perinucleolar chromatin (p < 0.01) and dense fibrillar components (p < 0.01). Finally, left ventricular function parameters were related with nucleolin levels in ischemic hearts (p < 0.0001). The present study demonstrates that HF influences on morphology and organization of nucleolar components, revealing changes in the expression and in the levels of nucleolin protein.

Celebrities Gather to Fight Heart Disease

Science.gov (United States)

... Current Issue Past Issues Celebrities Gather to Fight Heart Disease Past Issues / Spring 2007 Table of Contents For ... Kit to offer community education programs on women's heart disease. Organize heart-health screening events and health fairs ...

Heart Valve Surgery Recovery and Follow Up

Science.gov (United States)

... Guide: Understanding Your Heart Valve Problem | Spanish Symptom Tracker | Spanish Pre-surgery Checklist | Spanish What Is Heart ... Heart Valves • Heart Valve Problems and Causes • Risks, Signs and Symptoms • Accurate Diagnosis • Treatment Options • Recovery and ...

Rethinking Heart Failure

OpenAIRE

F?rstenwerth, Hauke

2012-01-01

An increasing body of clinical observations and experimental evidence suggests that cardiac dysfunction results from autonomic dysregulation of the contractile output of the heart. Excessive activation of the sympathetic nervous system and a decrease in parasympathetic tone are associated with increased mortality. Elevated levels of circulating catecholamines closely correlate with the severity and poor prognosis in heart failure. Sympathetic over-stimulation causes increased levels of catech...

Genetics Home Reference: critical congenital heart disease

Science.gov (United States)

... Facebook Twitter Home Health Conditions Critical congenital heart disease Critical congenital heart disease Printable PDF Open All Close All ... for Disease Control and Prevention: Congenital Heart Defects Disease InfoSearch: Congenital Heart Defects KidsHealth from Nemours Lucile Packard Children's ...

[Genetics of congenital heart diseases].

Science.gov (United States)

Bonnet, Damien

2017-06-01

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

Heart Failure Association of the European Society of Cardiology Specialist Heart Failure Curriculum

DEFF Research Database (Denmark)

McDonagh, Theresa A; Gardner, Roy S; Lainscak, Mitja

2014-01-01

Training Curricula. In addition, European Society of Cardiology (ESC) subspecialty curricula exist for Interventional Cardiology and Heart Rhythm Management. The purpose of this heart failure curriculum is to provide a framework which can be used as a blueprint for training across Europe. This blueprint...... mirrors other ESC curricula. Each section has three components: the knowledge required, the skills which are necessary, and the professionalism (attitudes and behaviours) which should be attained. The programme is designed to last 2 years. The first year is devoted to the specialist heart failure module...

Diabetes Mellitus and Heart Failure.

Science.gov (United States)

Lehrke, Michael; Marx, Nikolaus

2017-06-01

Epidemiologic and clinical data from the last 2 decades have shown that the prevalence of heart failure in diabetes is very high, and the prognosis for patients with heart failure is worse in those with diabetes than in those without diabetes. Experimental data suggest that various mechanisms contribute to the impairment in systolic and diastolic function in patients with diabetes, and there is an increased recognition that these patients develop heart failure independent of the presence of coronary artery disease or its associated risk factors. In addition, current clinical data demonstrated that treatment with the sodium glucose cotransporter 2 inhibitor empagliflozin reduced hospitalization for heart failure in patients with type 2 diabetes mellitus and high cardiovascular risk. This review article summarizes recent data on the prevalence, prognosis, pathophysiology, and therapeutic strategies to treat patients with diabetes and heart failure. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Cell migration during heart regeneration in zebrafish.

Science.gov (United States)

Tahara, Naoyuki; Brush, Michael; Kawakami, Yasuhiko

2016-07-01

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

Plasma microvesicle analysis identifies microRNA 129-5p as a biomarker of heart failure in univentricular heart disease.

Directory of Open Access Journals (Sweden)

Sweta Ramachandran

Full Text Available Biomarkers of heart failure in adults have been extensively studied. However, biomarkers to monitor the progression of heart failure in children with univentricular physiology are less well understood. We proposed that as mediators of diverse pathophysiology, miRNAs contained within circulating microvesicles could serve as biomarkers for the presence and progression of heart failure in univentricular patients. To test this, we studied the association of heart failure with elevations in specific miRNAs isolated from circulating microvesicles in a cohort of children with univentricular heart disease and heart failure. We conducted a single site cross-sectional observational study of 71 children aged 1 month-7 years with univentricular heart disease and heart failure. We demonstrated that levels of miR129-5p isolated from plasma microvesicles were inversely related to the degree of clinical heart failure as assessed by Ross score. We then showed that miR129-5p levels are downregulated in HL1 cells and human embryonic stem cell-derived cardiomyocytes exposed to oxidative stress. We demonstrated that bone morphogenetic protein receptor 2, which has been implicated in the development of pulmonary vascular disease, is a target of miR129-5p, and conversely regulated in response to oxidative stress in cell culture. Levels of miR129-5p were inversely related to the degree of clinical heart failure in patients with univentricular heart disease. This study demonstrates that miR129-5p is a sensitive and specific biomarker for heart failure in univentricular heart disease independent of ventricular morphology or stage of palliation. Further study is warranted to understand the targets affected by miR129-5p with the development of heart failure in patients with univentricular physiology.

Heart rate variability in healthy population

International Nuclear Information System (INIS)

Alamgir, M.; Hussain, M.M.

2010-01-01

Background: Heart rate variability has been considered as an indicator of autonomic status. Little work has been done on heart rate variability in normal healthy volunteers. We aimed at evolving the reference values of heart rate variability in our healthy population. Methods: Twenty-four hour holter monitoring of 37 healthy individuals was done using Holter ECG recorder 'Life card CF' from 'Reynolds Medical'. Heart rate variability in both time and frequency domains was analysed with 'Reynolds Medical Pathfinder Digital/700'. Results: The heart rate variability in normal healthy volunteers of our population was found in time domain using standard deviation of R-R intervals (SDNN), standard deviation of average NN intervals (SDANN), and Square root of the mean squared differences of successive NN intervals (RMSSD). Variation in heart rate variability indices was observed between local and foreign volunteers and RMSSD was found significantly increased (p<0.05) in local population. Conclusions: The values of heart rate variability (RMSSD) in healthy Pakistani volunteers were found increased compared to the foreign data reflecting parasympathetic dominance in our population. (author)

Heart check: the development and evolution of an organizational heart health assessment.

Science.gov (United States)

Golaszewski, Thomas; Fisher, Brian

2002-01-01

The purpose of this article is to document the development, testing, and application of an organizational assessment tool used to measure employer support for heart health. Additional information is presented on its future research and applications plan. This article represents the pooling of results from multiple studies using a variety of designs, including pilot tests, cross-sectional analyses, and quasi-experiments. Worksites covering the spectrum of employers across industry types and size, and throughout all of New York State. Over 10,000 New York employees and 1000 New York employers are represented in the multiple phases of this research. Heart Check is a 226-item inventory designed to measure such features in the worksite as organizational foundations, administrative supports, tobacco control, nutrition support, physical activity support, stress management, screening services, and company demographics. Additional side studies used professional judgments and behavioral surveys. As an assessment tool Heart Check shows evidence for reliability and validity. Applications of the instrument show characteristics that define high-scoring companies, quasi standards for New York employers, and, when applied during interventions, positive changes in organizational support levels. A relatively inexpensive, easy-to-use, and metrically tested instrument exists for measuring the construct of organizational support for employee heart health. The instrument shows promise as part of a system to enhance heart health through public health-based interventions in the workplace.

Validation of the Seattle Heart Failure Model (SHFM) in Heart Failure Population

International Nuclear Information System (INIS)

Hussain, S.; Kayani, A.M.; Munir, R.

2014-01-01

Objective: To determine the effectiveness of Seattle Heart Failure Model (SHFM) in a Pakistani systolic heart failure cohort in predicting mortality in this population. Study Design: Cohort study. Place and Duration of Study: The Armed Forces Institute of Cardiology - National Institute of Heart Diseases, Rawalpindi, from March 2011 to March 2012. Methodology: One hundred and eighteen patients with heart failure (HF) from the registry were followed for one year. Their 1-year mortality was calculated using the SHFM software on their enrollment into the registry. After 1-year predicted 1-year mortality was compared with the actual 1-year mortality of these patients. Results: The mean age was 41.6 +- 14.9 years (16 - 78 years). There were 73.7% males and 26.3% females. One hundred and fifteen patients were in NYHA class III or IV. Mean ejection fraction in these patients was 23 +- 9.3%. Mean brain natriuretic peptide levels were 1230 A+- 1214 pg/mL. Sensitivity of the model was 89.3% with 71.1% specificity, 49% positive predictive value and 95.5% negative predictive value. The accuracy of the model was 75.4%. In Roc analysis, AUC for the SHFM was 0.802 (p<0.001). conclusion: SHFM was found to be reliable in predicting one year mortality among patients with heart failure in the pakistan patients. (author)

Developing New Treatments for Heart Failure: Focus on the Heart.

Science.gov (United States)

Gheorghiade, Mihai; Larson, Christopher J; Shah, Sanjiv J; Greene, Stephen J; Cleland, John G F; Colucci, Wilson S; Dunnmon, Preston; Epstein, Stephen E; Kim, Raymond J; Parsey, Ramin V; Stockbridge, Norman; Carr, James; Dinh, Wilfried; Krahn, Thomas; Kramer, Frank; Wahlander, Karin; Deckelbaum, Lawrence I; Crandall, David; Okada, Shunichiro; Senni, Michele; Sikora, Sergey; Sabbah, Hani N; Butler, Javed

2016-05-01

Compared with heart failure (HF) care 20 to 30 years ago, there has been tremendous advancement in therapy for ambulatory HF with reduced ejection fraction with the use of agents that block maladaptive neurohormonal pathways. However, during the past decade, with few notable exceptions, the frequency of successful drug development programs has fallen as most novel therapies have failed to offer incremental benefit or raised safety concerns (ie, hypotension). Moreover, no therapy has been approved specifically for HF with preserved ejection fraction or for worsening chronic HF (including acutely decompensated HF). Across the spectrum of HF, preliminary results from many phase II trials have been promising but are frequently followed by unsuccessful phase III studies, highlighting a disconnect in the translational process between basic science discovery, early drug development, and definitive clinical testing in pivotal trials. A major unmet need in HF drug development is the ability to identify homogeneous subsets of patients whose underlying disease is driven by a specific mechanism that can be targeted using a new therapeutic agent. Drug development strategies should increasingly consider therapies that facilitate reverse remodeling by directly targeting the heart itself rather than strictly focusing on agents that unload the heart or target systemic neurohormones. Advancements in cardiac imaging may allow for more focused and direct assessment of drug effects on the heart early in the drug development process. To better understand and address the array of challenges facing current HF drug development, so that future efforts may have a better chance for success, the Food and Drug Administration facilitated a meeting on February 17, 2015, which was attended by clinicians, researchers, regulators, and industry representatives. The following discussion summarizes the key takeaway dialogue from this meeting. © 2016 American Heart Association, Inc.

Cyanotic congenital heart disease and atherosclerosis

DEFF Research Database (Denmark)

Tarp, Julie Bjerre; Jensen, Annette Schophuus; Engstrøm, Thomas

2017-01-01

Improved treatment options in paediatric cardiology and congenital heart surgery have resulted in an ageing population of patients with cyanotic congenital heart disease (CCHD). The risk of acquired heart disease such as atherosclerosis increases with age.Previous studies have speculated whether...

How the Heart Works

Science.gov (United States)

... direction that blood flows through your heart. The light blue arrow shows that blood enters the right atrium of your heart from ... to your lungs through the pulmonary arteries. The light red arrow shows oxygen-rich blood coming from your lungs through the pulmonary veins ...

Thyroid and the Heart

Directory of Open Access Journals (Sweden)

A Karas

2009-09-01

Full Text Available The cardiovascular signs and symptoms of thyroid disease are some of the most clinically relevant findings that accompany both hyperthyroidism and hypothyroidism. On the basis of the understanding of the mechanisms of thyroid hormone action on the heart and cardiovascular system, it is possible to explain the changes in cardiac output, cardiac contractility, blood pressure and rhythm disturbances that result from thyroid dysfunction. In the present review will integrate what is known about the mechanisms of thyroid hormone action on the heart and the alterations in thyroid hormone metabolism that accompany chronic congestive heart failure.

Effect of mibefradil on heart rate variability in patients with chronic heart failure

NARCIS (Netherlands)

Brouwer, J; de Kam, PJ; Haaksma, J; Crijns, HJGM; van Veldhuisen, DJ

2000-01-01

Background: Mibefradil was recently withdrawn from the market because of an unfavorable clinical profile in patients with chronic heart failure. Although drug interactions appear to play a role, other mechanisms such as proarrhythmia and autonomic deterioration could also be relevant. Chronic heart

Configuration design and accuracy analysis of a novel magneto rheological finishing machine tool for concave surfaces with small radius of curvature

International Nuclear Information System (INIS)

Liu, Henan; Chen, Mingjun; Yu, Bo; Zhen, Fang

2016-01-01

Magnetorheological finishing (MRF) is a computer-controlled deterministic polishing technique that is widely used in the production of high-quality optics. In order to overcome the defects of existing MRF processes that are unable to achieve concave surfaces with small radius of curvature, a configuration method of a novel structured MRF machine tool using small ball-end permanent-magnet polishing head is proposed in this paper. The preliminary design focuses on the structural configuration of the machine, which includes the machine body, motion units and accessory equipment, and so on. Structural deformation and fabrication accuracy of the machine are analyzed theoretically, in which the reasonable structure sizes, manufacturing errors and assembly errors of main structural components are given for configuration optimization. Based on the theoretical analysis, a four-axes linkage MRF machine tool is developed. Preliminary experiments of spot polishing are carried out and the results indicate that the proposed MRF process can achieve stable polishing area which meets requirement of deterministic polishing. A typical small-bore complex component is polished on the developed device and fine surface quality is obtained with sphericity of the finished spherical surfaces 1.3 μm and surface roughness Ra less than 0.018 μm.

Heart pacemaker

Science.gov (United States)

Cardiac pacemaker implantation; Artificial pacemaker; Permanent pacemaker; Internal pacemaker; Cardiac resynchronization therapy; CRT; Biventricular pacemaker; Arrhythmia - pacemaker; Abnormal heart ...

Physical correlates of radiologic heart volume

International Nuclear Information System (INIS)

Christie, D.

1978-01-01

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

EFFECT OF FUROSEMIDE AND TORASEMIDE ON HEART RATE VARIABILITY AND VENTRICULAR RHYTHM DISORDERS IN PATIENTS WITH CHRONIC HEART FAILURE COMPLICATING ISCHEMIC HEART DISEASE: COMPARATIVE NONRANDOMIZED STUDY

Directory of Open Access Journals (Sweden)

H. H. Shugushev

2010-01-01

Full Text Available Aim. To study effect of diuretic therapy with furosemide and torasemide on heart rate variability (HRV and frequency of ventriclar rhythm disorders in patients with chronic heart failure (CHF complicating ischemic heart disease (IHD.Material and methods. Patients (n=107 with CHF III-IV functional class (NYHA complicating IHD were examined. The first group of patients received furosemide, 20-60 mg QD (n=52, the second group received torasemide, 5-20 mg QD (n=55. Analysis of heart rhythm disorders and the basic HRV indicators was performed by ECG 10-minute recordings initially and after 10 days of therapy.Results. Decrease in time and spectral HRV parameters and increase in daily number of ventricular extrasystoles was found in furosemide treated patients. Improvement of HRV parameters and reduction of daily number of ventricular rhythm disorders was found torasemide treated patients.Conclusion. Torasemide therapy improves an autonomic regulation of heart rhythm and leads to the reduction of ventricular heart rhythm disorders in patients with CHF complicating IHD.

Cigarette Smoking and Incident Heart Failure: Insights From the Jackson Heart Study.

Science.gov (United States)

Kamimura, Daisuke; Cain, Loretta R; Mentz, Robert J; White, Wendy B; Blaha, Michael J; DeFilippis, Andrew P; Fox, Ervin R; Rodriguez, Carlos J; Keith, Rachel J; Benjamin, Emelia J; Butler, Javed; Bhatnagar, Aruni; Robertson, Rose M; Winniford, Michael D; Correa, Adolfo; Hall, Michael E

2018-06-12

Cigarette smoking has been linked with several factors associated with cardiac dysfunction. We hypothesized that cigarette smoking is associated with left ventricular (LV) structure and function, and incident heart failure (HF) hospitalization. We investigated 4129 (never smoker n=2884, current smoker n=503, and former smoker n=742) black participants (mean age, 54 years; 63% women) without a history of HF or coronary heart disease at baseline in the Jackson Heart Study. We examined the relationships between cigarette smoking and LV structure and function by using cardiac magnetic resonance imaging among 1092 participants, cigarette smoking and brain natriuretic peptide levels among 3325 participants, and incident HF hospitalization among 3633 participants with complete data. After adjustment for confounding factors, current smoking was associated with higher mean LV mass index and lower mean LV circumferential strain ( P <0.05, for both) in comparison with never smoking. Smoking status, intensity, and burden were associated with higher mean brain natriuretic peptide levels (all P <0.05). Over 8.0 years (7.7-8.0) median follow-up, there were 147 incident HF hospitalizations. After adjustment for traditional risk factors and incident coronary heart disease, current smoking (hazard ratio, 2.82; 95% confidence interval, 1.71-4.64), smoking intensity among current smokers (≥20 cigarettes/d: hazard ratio, 3.48; 95% confidence interval, 1.65-7.32), and smoking burden among ever smokers (≥15 pack-years: hazard ratio, 2.06; 95% confidence interval, 1.29-3.3) were significantly associated with incident HF hospitalization in comparison with never smoking. In blacks, cigarette smoking is an important risk factor for LV hypertrophy, systolic dysfunction, and incident HF hospitalization even after adjusting for effects on coronary heart disease. © 2018 American Heart Association, Inc.

Are there long-term benefits in following stable heart failure patients in a heart failure clinic?

DEFF Research Database (Denmark)

Leetmaa, Tina; Villadsen, Henrik; Mikkelsen, Kirsten

2008-01-01

Objectives and Design. This study describes the long-term outcome of 163 patients with stable mild to moderate heart failure (NYHA II-III), who already were enrolled in a heart failure clinic and now were randomized to continued follow-up in the heart failure (HF) clinic or else to usual care (UC...

Dental Health and Heart Health

Science.gov (United States)

... Check Recipe Certification Program Nutrition Requirements Heart-Check Professional Resources Contact the Heart-Check Certification Program Simple Cooking and Recipes Dining Out Choosing a Restaurant Deciphering ...

Mental Health and Heart Health

Science.gov (United States)

... Check Recipe Certification Program Nutrition Requirements Heart-Check Professional Resources Contact the Heart-Check Certification Program Simple Cooking and Recipes Dining Out Choosing a Restaurant Deciphering ...

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

Science.gov (United States)

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

2016-02-01

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

SenseMyHeart: A cloud service and API for wearable heart monitors.

Science.gov (United States)

Pinto Silva, P M; Silva Cunha, J P

2015-01-01

In the era of ubiquitous computing, the growing adoption of wearable systems and body sensor networks is trailing the path for new research and software for cardiovascular intensity, energy expenditure and stress and fatigue detection through cardiovascular monitoring. Several systems have received clinical-certification and provide huge amounts of reliable heart-related data in a continuous basis. PhysioNet provides equally reliable open-source software tools for ECG processing and analysis that can be combined with these devices. However, this software remains difficult to use in a mobile environment and for researchers unfamiliar with Linux-based systems. In the present paper we present an approach that aims at tackling these limitations by developing a cloud service that provides an API for a PhysioNet-based pipeline for ECG processing and Heart Rate Variability measurement. We describe the proposed solution, along with its advantages and tradeoffs. We also present some client tools (windows and Android) and several projects where the developed cloud service has been used successfully as a standard for Heart Rate and Heart Rate Variability studies in different scenarios.

Parallel paths to improve heart failure outcomes

DEFF Research Database (Denmark)

Albert, Nancy M.

2013-01-01

-based, heart failure guidelines improves clinical outcomes. Thus, nurses and patients are on parallel paths related to setting the foundation for improved self-care adherence in advanced heart failure. Through research, we found that nurses were not adequately prepared as heart failure educators...... and that patients did not believe they were able to control heart failure. In 2 educational intervention studies that aimed to help patients understand that they could control fluid management and follow a strict daily fluid limit, patients had improved clinical outcomes. Thus, misperceptions about heart failure......Gaps and disparities in delivery of heart failure education by nurses and performance in accomplishing self-care behaviors by patients with advanced heart failure may be factors in clinical decompensation and unplanned consumption of health care. Is nurse-led education effectively delivered before...

201Tl heart studies

International Nuclear Information System (INIS)

Bell, R.L.

1976-01-01

At the annual meeting of the Society of Nuclear Medicine there was a preponderance of papers dealing with the heart. The most impressive papers detailed the use of monovalent cation 201 Tl in the evaluation of coronary artery disease. Thallium-201 behaves like potassium in that it enters heart muscle quickly and persists in that organ for several hours. It is unlike most radioactive potassium analogues used for heart studies in that: (1) its gamma energy peaks (69 keV and 80 keV) are more easily collimated with resultant image improvement, (2) its physical half life of 72 hours is sufficiently short to attain high counting rates without too much radiation and is sufficiently long so that storage is not prohibitive, (3) its short half life and lack of Beta radiation results in lower radiation to the patient, and (4) its uptake in heart is greater and uptake in liver and stomach less than other potassium analogues

Renal anomalies in congenital heart disease

International Nuclear Information System (INIS)

Lee, Byung Hee; Kim, In One; Yeon, Kyung Mo; Yoon, Yong Soo

1987-01-01

In general, the incidence of urinary tract anomalies in congenital heart disease is higher than that in general population. So authors performed abdominal cineradiography in 1045 infants and children undergoing cineangiographic examinations for congenital heart disease, as a screening method for the detection, the incidence, and the nature of associated urinary tract anomalies. The results were as follows: 1. The incidence of urinary tract anomaly associated with congenital heart disease was 4.1% (<2% in general population). 2. Incidence of urinary tract anomalies was 4.62% in 671 acyanotic heart diseases, 3.20% in 374 cyanotic heart diseases. 3. There was no constant relationship between the type of cardiac anomaly and the type of urinary tract anomaly

Xamoterol in severe congestive heart failure

DEFF Research Database (Denmark)

Tangø, M; Lyngborg, K; Mehlsen, J

1992-01-01

Twelve patients in severe congestive heart failure were given placebo, 100 mg xamoterol (Corwin) twice daily and 200 mg xamoterol twice daily, respectively, in 3 two-week periods in a double-blind randomised study. At the end of each treatment period the patients were evaluated. No differences were...... found between placebo and xamoterol in the following parameters: New York Heart Association function group index, heart volume, body weight, exercise duration on bicycle and treadmill, heart rate and systolic and diastolic blood pressure at rest. However, during exercise we found significantly lower...... heart rate and rate-pressure product during xamoterol treatment. This reduction is probably indicating occupation of beta-adrenoreceptors with concomitant reduced oxygen consumption during exercise....

Learning by Heart: Students Use Heart Rate Patterns To Identify Nervous System Imbalances.

Science.gov (United States)

Ackerly, Spafford C.

2001-01-01

Introduces a science unit on heart rate variability (HVR) patterns. Uses spectral analysis to determine the effects of environmental stimulants such as music and emotional stress on heart rate. Observes relaxation techniques and their effects on the autonomous nervous system. (Contains 12 references.) (YDS)

Definition and Classification of Heart Failure

Directory of Open Access Journals (Sweden)

Mitja Lainscak

2017-01-01

Full Text Available A review of the definition and classification of heart failure, updated since the recent 2016 European Society of Cardiology guidelines for the diagnosis and treatment of acute and chronic heart failure. Heart failure is defined by the European Society of Cardiology (ESC as a clinical syndrome characterised by symptoms such as shortness of breath, persistent coughing or wheezing, ankle swelling and fatigue, that may be accompanied by the following signs: jugular venous pressure, pulmonary crackles, increased heart rate and peripheral oedema. However, these signs may not be present in the early stages and in patients treated with diuretics. When apparent, they are due to a structural and/or functional cardiac abnormality, leading to systolic and/or diastolic ventricular dysfunction, resulting in a reduced cardiac output and/or elevated intra- cardiac pressures at rest or during stress. According to the most recent ESC guidelines the initial evaluation of patients with suspected heart failure should include a clinical history and physical examination, laboratory assessment, chest radiography, and electrocardiography. Echocardiography can confirm the diagnosis. Beyond detecting myocardial abnormality, other impairments such as abnormalities of the valves, pericardium, endocardium, heart rhythm, and conduction may be found. The identification of the underlying aetiology is pivotal for the diagnosis of heart failure and its treatment. The authors review the definitions and classifications of heart failure.

Heart rate, heart rate variability, and arrhythmias in dogs with myxomatous mitral valve disease

DEFF Research Database (Denmark)

Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth

2012-01-01

Autonomic modulation of heart rhythm is thought to influence the pathophysiology of myxomatous mitral valve disease (MMVD).......Autonomic modulation of heart rhythm is thought to influence the pathophysiology of myxomatous mitral valve disease (MMVD)....

Comparison between evaluations of the glenoid concavity by double oblique axial MR arthrography and clinical results in arthroscopic bankart repair

International Nuclear Information System (INIS)

Maeda, Shugo; Ishibashi, Yasuyuki; Tsuda, Eiichi; Yamamoto, Yuji; Toh, Satoshi; Sasaki, Taisuke

2011-01-01

The purpose of this study was to compare the findings obtained in the glenoid concavity by double oblique axial MR arthrography (DOA-MRA) and the clinical outcome after arthroscopic Bankart repair. The results in 57 shoulders of 50 patients who underwent arthroscopic Bankart repair were reviewed. The pre and postoperative lesions in the inferior glenohumeral ligament labrum complex (IGHLLC) were classified into 5 morphological types based on the DOA-MRA findings prominent (P), split (S), flat (F), detached (D), and capsular tear (C). The height and slope of the anterior labrum from the glenoid fossa were measured on the DOA-MRA images. The Japan Shoulder Society Shoulder Instability Score (JSS-SIS) system was used to evaluate the affected shoulder of all of the patients after surgery. There were no significant differences between the JSS-SISs of the shoulders in the P group, F group, and S+D group (recurrent Bankart lesion) 6 months postoperatively. There were significant increases in the slope and height of all of the shoulders as a whole between the preoperative period and 3 months postoperatively, but there were no statistically significant differences in the slope or height between 3 months and 6 months postoperatively. The initial capsulolabral buttress property was maintained at 6 months after arthroscopic Bankart repair, and there was no correlation between the morphology of the IGHLLC and the JSS-SISs. (author)

Educational series in congenital heart disease:Congenital left-sided heart obstruction

OpenAIRE

Carr, Michelle; Curtis, Stephanie; Marek, Jan

2018-01-01

Congenital obstruction of the left ventricular outflow tract remains a significant problem and multilevel obstruction can often coexist. Obstruction can take several morphological forms and may involve the subvalvar, valvar or supravalvar portion of the aortic valve complex. Congenital valvar stenosis presenting in the neonatal period represents a spectrum of disorders ranging from the hypoplastic left heart syndrome to almost normal hearts. Treatment options vary dependent on the severity of...

Sacubitril/Valsartanstive Heart Failure: Cardiogenic Shock

Directory of Open Access Journals (Sweden)

H. A. Rawal

2018-01-01

Full Text Available Sacubitril/valsartan is a combination drug described as a new class of dual-acting angiotensin receptor-neprilysin inhibitor (ARNi for heart failure. We present a case of a patient with NYHA class IV systolic heart failure who was refractory to all other classes of heart failure medications and was started on this new medication. On sacubitril/valsartan, he developed cardiogenic shock. This led us to reevaluate the use and risks of this medication in the class IV heart failure population.

Sacubitril/Valsartanstive Heart Failure: Cardiogenic Shock

OpenAIRE

Rawal, H. A.; Kocheril, A. G.

2018-01-01

Sacubitril/valsartan is a combination drug described as a new class of dual-acting angiotensin receptor-neprilysin inhibitor (ARNi) for heart failure. We present a case of a patient with NYHA class IV systolic heart failure who was refractory to all other classes of heart failure medications and was started on this new medication. On sacubitril/valsartan, he developed cardiogenic shock. This led us to reevaluate the use and risks of this medication in the class IV heart failure population.

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

Science.gov (United States)

Bhaduri, Anirban; Bhaduri, Susmita; Ghosh, Dipak

2017-09-01

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

The Eurotransplant High-Urgency Heart Transplantation Program: an option for patients in acute heart failure?

Science.gov (United States)

Koch, A; Tochtermann, U; Remppis, A; Dengler, T J; Schnabel, P A; Hagl, S; Sack, F U

2006-09-01

The Eurotransplant High-Urgency (HU) Heart Transplantation Program allows urgent heart transplants to be carried out in rapidly deteriorating patients with acute-to-chronic heart failure on the elective waiting list. But do the results of HU heart transplantation justify performing primary heart transplantation in these critically ill patients and offer an acceptable outcome? Between 2000 and 2004, 64 heart transplantations (HTx) (32 elective and 32 HU-HTx) were performed in our department. After having been accepted in an auditing process based on HU criteria, intensive care patients in NYHA functional class IV (cardiac index 1.7 l/min/qm BS), in end-organ failure (creatinine 1.5 mg/dl), and with catecholamine dependence (dobutamine 8 microg/kg/min), are given priority with respect to organ allocation, and their data were compared to data from elective patients from the same period. HU requests were accepted in 97 % of cases. Two requests were not accepted, and both patients with contraindications for assist device implantation died within one week. The HU patients were 100 % in NYHA class IV, 93 % of the elective patients were in NYHA class III. Waiting time on the HU list was 13 days, and 7 of these patients died before HTx. Following heart transplantation, survival rates at 30 days and at one year of the HU group were 88 % and 85 % versus 94 % and 93 % in the elective group. This study shows that end-stage heart failure patients in the HU program can be transplanted primarily with good results if an organ is available in time. We are still in the position where the HU program only manages the organ shortage; there are still too many patients on the waiting list who die before receiving a donor organ.

American Heart Association's Life's Simple 7: Avoiding Heart Failure and Preserving Cardiac Structure and Function.

Science.gov (United States)

Folsom, Aaron R; Shah, Amil M; Lutsey, Pamela L; Roetker, Nicholas S; Alonso, Alvaro; Avery, Christy L; Miedema, Michael D; Konety, Suma; Chang, Patricia P; Solomon, Scott D

2015-09-01

Many people may underappreciate the role of lifestyle in avoiding heart failure. We estimated whether greater adherence in middle age to American Heart Association's Life's Simple 7 guidelines—on smoking, body mass, physical activity, diet, cholesterol, blood pressure, and glucose—is associated with lower lifetime risk of heart failure and greater preservation of cardiac structure and function in old age. We studied the population-based Atherosclerosis Risk in Communities Study cohort of 13,462 adults ages 45-64 years in 1987-1989. From the 1987-1989 risk factor measurements, we created a Life's Simple 7 score (range 0-14, giving 2 points for ideal, 1 point for intermediate, and 0 points for poor components). We identified 2218 incident heart failure events using surveillance of hospital discharge and death codes through 2011. In addition, in 4855 participants free of clinical cardiovascular disease in 2011-2013, we performed echocardiography from which we quantified left ventricular hypertrophy and diastolic dysfunction. One in four participants (25.5%) developed heart failure through age 85 years. Yet, this lifetime heart failure risk was 14.4% for those with a middle-age Life's Simple 7 score of 10-14 (optimal), 26.8% for a score of 5-9 (average), and 48.6% for a score of 0-4 (inadequate). Among those with no clinical cardiovascular event, the prevalence of left ventricular hypertrophy in late life was approximately 40% as common, and diastolic dysfunction was approximately 60% as common, among those with an optimal middle-age Life's Simple 7 score, compared with an inadequate score. Greater achievement of American Heart Association's Life's Simple 7 in middle age is associated with a lower lifetime occurrence of heart failure and greater preservation of cardiac structure and function. Copyright © 2015 Elsevier Inc. All rights reserved.

Ischaemic heart disease

International Nuclear Information System (INIS)

Ruttley, M.

1985-01-01

Radiology has an important role in the diagnosis and management of ischaemic heart disease, notably in the investigation of angina pectoris, the monitoring of acute myocardial infarction and the assessment of its non-fatal complications; recent application of catheter techniques to the treatment of ischaemic heart disease has been a progression from Dotter's original work on peripheral arterial dilation made possible by Gruntzig's development of a suitable dilating catheter for coronary stenosis

Acute heart failure

OpenAIRE

Sénior Sánchez, Juan Manuel; Gándara Ricardo, Jairo Alfonso

2015-01-01

We describe the clinical case of a 26 year-old woman who came to Hospital Universitario San Vicente Fundación (Medellín, Colombia) with symptoms and signs of acute heart failure. She had been previously diagnosed with chronic heart failure with reduced ejection fraction without clear origin, pulmonary thromboembolism and ischemic stroke, without optimal neurohormonal modulation. She was admitted with clinical findings of fluid overload and low tissue perfusion, with inotropic support requirem...

Transplantation of Hearts Donated after Circulatory Death

Directory of Open Access Journals (Sweden)

Christopher W. White

2018-02-01

Full Text Available Cardiac transplantation has become limited by a critical shortage of suitable organs from brain-dead donors. Reports describing the successful clinical transplantation of hearts donated after circulatory death (DCD have recently emerged. Hearts from DCD donors suffer significant ischemic injury prior to organ procurement; therefore, the traditional approach to the transplantation of hearts from brain-dead donors is not applicable to the DCD context. Advances in our understanding of ischemic post-conditioning have facilitated the development of DCD heart resuscitation strategies that can be used to minimize ischemia-reperfusion injury at the time of organ procurement. The availability of a clinically approved ex situ heart perfusion device now allows DCD heart preservation in a normothermic beating state and minimizes exposure to incremental cold ischemia. This technology also facilitates assessments of organ viability to be undertaken prior to transplantation, thereby minimizing the risk of primary graft dysfunction. The application of a tailored approach to DCD heart transplantation that focuses on organ resuscitation at the time of procurement, ex situ preservation, and pre-transplant assessments of organ viability has facilitated the successful clinical application of DCD heart transplantation. The transplantation of hearts from DCD donors is now a clinical reality. Investigating ways to optimize the resuscitation, preservation, evaluation, and long-term outcomes is vital to ensure a broader application of DCD heart transplantation in the future.

ECHOCARDIOGRAPHIC DIAGNOSTICS OF CARCINOID HEART DISEASE

Directory of Open Access Journals (Sweden)

Janez Ravnik

2002-09-01

Full Text Available Background. Carcinoid heart disease is a rare heart disease which affects endocard and heart valves on the right side of heart. It affects only patients with manifested carcinoid syndrome, which is thought to be the consequence of secretory active metastases of carcinoid tumour. The carcinoid endocardial plaques cause structural changes of tricuspid and pulmonic valve and later on their stenosis and/or insufficiency.Patients and methods. In this article we introduce a carcinoid valve heart disease (CVHD scoring system for easier end exact echocardiographic diagnostics. Four echocardiographic parameters are beeing estimated: structural changes of tricuspid valve, tricuspid valve regurgitation, stenosis of pulmonic valve and pulmonic valve regurgitation.Conclusions. The scoring system allows us to make an early diagnosis and evaluation of progression of carcinoid heart disease, which is very important for planning the treatment process. Our experiences confirm the usefulness of this scoring system in echocardiographic follow–up of patients with carcinoid syndrome.

Primary fibro sarcoma of the heart.

Science.gov (United States)

Kabashi, Serbeze; Hoxha, Naim; Gashi, Shkelzen; Ahmegjekaj, Ilir; Bejta, Ilir; Sadiku, Muharrem; Ymeri, Halit; Kabashi, Antigona; Bicaj, Xhavit; Mucaj, Sefedin

2013-01-01

Primary malignant heart tumors represent rare entities where fibro sarcoma represents about 3% of all. Introducing the patient: A 15 years old patient with cardiac insufficiency (heart failure) symptoms, such as weakness, cyanosis, palpitations and breathing difficulties; enlargement of upper mediastinum and pleural effusion. Through echocardiography a pericardial effusion and intracavitary thrombus in atrium was diagnosed. With computed tomography is diagnosed a tumoral mass in right atrium which is also spread in the right ventricle of the heart. Tumor is completely removed; pat histology result showed primary fibro sarcoma of the heart. At that time no metastasis was found. Conclusion. Primary malignant heart tumors may manifest like cardiac insufficiency or like systemic diseases. Fibrosarcomas are rare and have bad prognosis. On average patients can live around six months after initial symptoms appeared and diagnosis of the tumor was done. In the case of cardiac insufficiency with differential diagnosis we should also think of heart tumors, which could certainly be proved for or eliminated by echocardiography.

Is our heart a well-designed pump? The heart along animal evolution.

Science.gov (United States)

Bettex, Dominique A; Prêtre, René; Chassot, Pierre-Guy

2014-09-07

A carrier system for gases and nutrients became mandatory when primitive animals grew larger and developed different organs. The first circulatory systems are peristaltic tubes pushing slowly the haemolymph into an open vascular tree without capillaries (worms). Arthropods developed contractile bulges on the abdominal aorta assisted by accessory hearts for wings or legs and by abdominal respiratory motions. Two-chamber heart (atrium and ventricle) appeared among mollusks. Vertebrates have a multi-chamber heart and a closed circulation with capillaries. Their heart has two chambers in fishes, three chambers (two atria and one ventricle) in amphibians and reptiles, and four chambers in birds and mammals. The ventricle of reptiles is partially divided in two cavities by an interventricular septum, leaving only a communication of variable size leading to a variable shunt. Blood pressure increases progressively from 15 mmHg (worms) to 170/70 mmHg (birds) according to the increase in metabolic rate. When systemic pressure exceeds 50 mmHg, a lower pressure system appears for the circulation through gills or lungs in order to improve gas exchange. A four-chamber heart allows a complete separation of systemic and pulmonary circuits. This review describes the circulatory pumping systems used in the different classes of animals, their advantages and failures, and the way they have been modified with evolution. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

DNA methylation abnormalities in congenital heart disease.

Science.gov (United States)

Serra-Juhé, Clara; Cuscó, Ivon; Homs, Aïda; Flores, Raquel; Torán, Núria; Pérez-Jurado, Luis A

2015-01-01

Congenital heart defects represent the most common malformation at birth, occurring also in ∼50% of individuals with Down syndrome. Congenital heart defects are thought to have multifactorial etiology, but the main causes are largely unknown. We have explored the global methylation profile of fetal heart DNA in comparison to blood DNA from control subjects: an absolute correlation with the type of tissue was detected. Pathway analysis revealed a significant enrichment of differential methylation at genes related to muscle contraction and cardiomyopathies in the developing heart DNA. We have also searched for abnormal methylation profiles on developing heart-tissue DNA of syndromic and non-syndromic congenital heart defects. On average, 3 regions with aberrant methylation were detected per sample and 18 regions were found differentially methylated between groups. Several epimutations were detected in candidate genes involved in growth regulation, apoptosis and folate pathway. A likely pathogenic hypermethylation of several intragenic sites at the MSX1 gene, involved in outflow tract morphogenesis, was found in a fetus with isolated heart malformation. In addition, hypermethylation of the GATA4 gene was present in fetuses with Down syndrome with or without congenital heart defects, as well as in fetuses with isolated heart malformations. Expression deregulation of the abnormally methylated genes was detected. Our data indicate that epigenetic alterations of relevant genes are present in developing heart DNA in fetuses with both isolated and syndromic heart malformations. These epimutations likely contribute to the pathogenesis of the malformation by cis-acting effects on gene expression.

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Developments in mechanical heart valve prosthesis

Indian Academy of Sciences (India)

Artificial heart valves are engineered devices used for replacing diseased or damaged natural valves of the heart. Most commonly used for replacement are mechanical heart valves and biological valves. This paper briefly outlines the evolution, designs employed, materials being used,. and important factors that affect the ...

Healthy Heart Collaboration and Developed Toolkit

Science.gov (United States)

Impact: EPA is raising awareness of heart disease and its link to air pollution and other environmental factors as a partner in Million Hearts, a national initiative to prevent heart attacks and strokes. The talk will provide an up to date review of the evidence linking air poll...

Clinical pattern of heart diseases in children

International Nuclear Information System (INIS)

Ejaz, M.S.; Billoo, A.G.

2000-01-01

This study was done to determine various causes and clinical presentation of heart disease in children. It was a prospective hospital study conducted in Department of Pediatrics Civil Hospital, Karachi from August 1995 to February 1996. In this study, 70 patients of heart disease upto 12 years of age were inducted. There were 33 (47.14%) cases of congenital heart diseases and 37 (52.85%) cases of acquired heart diseases. The age distribution showed that heart disease was more frequent between 0-11 months of age (41.42%). Congenital heart diseases were also frequent between 0-11 months (28.57%). On the other hand acquired heart diseases were more common between 6-12 years (22.85%). In this study the males were predominantly involved, the male to female ratio was 1.05:1. In congenital heart disease it was 1.3:1 and in acquired heart diseases it was 0.85:1. Ventricular septal defect was the commonest congenital lesion reported (20%). Rheumatic fever and viral myocarditis were two frequently occurring acquired heart-diseases 17.14% each. The common presentation of heart diseases were respiratory distress (94.28%), fever (90%), feeding difficulty (57.14%) and failure to thrive (34.28%). In case of rheumatic fever, chorea was present in 8.57%, arthritis in 11.42% and S/C nodules (2.85%) cases respectively. The early management of the problem may help in decreasing morbidity and mortality due to these disease in children. Prenatal detection of congenital cardiac lesions by fetal echocardiography in high risk pregnancies, early intervention in neonatal period and counseling of the parents may help in prevention of congenital heart diseases in children. Primary prevention of rheumatic fever can be achieved by early diagnosis and treatment of streptococcal throat infection. (author)

Iron deficiency and anemia in heart failure.

Science.gov (United States)

Çavuşoğlu, Yüksel; Altay, Hakan; Çetiner, Mustafa; Güvenç, Tolga Sinan; Temizhan, Ahmet; Ural, Dilek; Yeşilbursa, Dilek; Yıldırım, Nesligül; Yılmaz, Mehmet Birhan

2017-03-01

Heart failure is an important community health problem. Prevalence and incidence of heart failure have continued to rise over the years. Despite recent advances in heart failure therapy, prognosis is still poor, rehospitalization rate is very high, and quality of life is worse. Co-morbidities in heart failure have negative impact on clinical course of the disease, further impair prognosis, and add difficulties to treatment of clinical picture. Therefore, successful management of co-morbidities is strongly recommended in addition to conventional therapy for heart failure. One of the most common co-morbidities in heart failure is presence of iron deficiency and anemia. Current evidence suggests that iron deficiency and anemia are more prevalent in patients with heart failure and reduced ejection fraction, as well as those with heart failure and preserved ejection fraction. Moreover, iron deficiency and anemia are referred to as independent predictors for poor prognosis in heart failure. There is strong relationship between iron deficiency or anemia and severity of clinical status of heart failure. Over the last two decades, many clinical investigations have been conducted on clinical effectiveness of treatment of iron deficiency or anemia with oral iron, intravenous iron, and erythropoietin therapies. Studies with oral iron and erythropoietin therapies did not provide any clinical benefit and, in fact, these therapies have been shown to be associated with increase in adverse clinical outcomes. However, clinical trials in patients with iron deficiency in the presence or absence of anemia have demonstrated considerable clinical benefits of intravenous iron therapy, and based on these positive outcomes, iron deficiency has become target of therapy in management of heart failure. The present report assesses current approaches to iron deficiency and anemia in heart failure in light of recent evidence.

Ontogenetic shifts of heart position in snakes.

Science.gov (United States)

Lillywhite, Harvey B; Lillywhite, Steven M

2017-08-01

Heart position relative to total body length (TL) varies among snakes, with anterior hearts in arboreal species and more centrally located hearts in aquatic or ground-dwelling species. Anterior hearts decrease the cardiac work associated with cranial blood flow and minimize drops in cranial pressure and flow during head-up climbing. Here, we investigate whether heart position shifts intraspecifically during ontogenetic increases in TL. Insular Florida cottonmouth snakes, Agkistrodon conanti, are entirely ground-dwelling and have a mean heart position that is 33.32% TL from the head. In contrast, arboreal rat snakes, Pantherophis obsoleta, of similar lengths have a mean heart position that is 17.35% TL from the head. In both species, relative heart position shifts craniad during ontogeny, with negative slopes = -.035 and -.021% TL/cm TL in Agkistrodon and Pantherophis, respectively. Using a large morphometric data set available for Agkistrodon (N = 192 individuals, 23-140 cm TL), we demonstrate there is an anterior ontogenetic shift of the heart position within the trunk (= 4.56% trunk length from base of head to cloacal vent), independent of head and tail allometry which are both negative. However, in longer snakes > 100 cm, the heart position reverses and shifts caudally in longer Agkistrodon but continues toward the head in longer individuals of Pantherophis. Examination of data sets for two independent lineages of fully marine snakes (Acrochordus granulatus and Hydrophis platurus), which do not naturally experience postural gravity stress, demonstrate both ontogenetic patterns for heart position that are seen in the terrestrial snakes. The anterior migration of the heart is greater in the terrestrial species, even if TL is standardized to that of the longer P. obsoleta, and compensates for about 5 mmHg gravitational pressure head if they are fully upright. © 2017 Wiley Periodicals, Inc.