Myocardial perfusion by contrast echocardiography. Establishment of normal pattern of intracoronary injection and safety in humans

OBJECTIVE: To establish the normal pattern and safety of echocardiographic contrast in patients with no significant obstruction of epicardial coronary arteries. METHODS: 67 patients with normal coronary arteries or obstructions < 50% were selected from 277 patients who underwent coronary angiography (CA). Mean age was 56 ± 11years and 36 were males. At the end CA, echocardiographic contrast was selectively injected into each coronary artery. The parasternal short axis of the left ventricle (LV) was divided into six segments: anterior (A), antero-lateral (AL), postero-lateral (PL), posterior (P), infero-septal (IS) and antero-septal (AS). Anterolateral (ALPM) and posteromedial papillary muscles (PMPM) were also considered. The pattern and intensity of the appearance of the myocardial contrast was visually analyzed. RESULTS: The right coronary artery (RCA) was dominant in 60 patients. Contrast appearance was sudden and simultaneous in the 3 muscle layers. All segments could be contrasted after the injection in both coronary arteries. 100% of the AS, A and AL segments, 97% of the PL and 98% of the ALPM were perfused by the left coronary artery (LCA). P and IS segments were perfused by the RCA in 85% and 82%, respectively, and by a dominant LCA in 71% of the cases. The PMPM was perfused by a dominant RCA in 77% and by a dominant LCA in 86%. There were no symptoms. CONCLUSION: Intracoronary injection of the sonicated solution is a safe procedure that allows for an excellent opacification of the myocardium and can potentially be used during routine CA.

Study of Coronary Flow Reserve with Intravenous Use of Microbubbles (Contrast Echocardiography) and Adenosine: Protocol for Clinical Application in Patients Suspected of Having Coronary Heart Disease

OBJECTIVE: To test the feasibility, safety and accuracy of the adenosine protocol in the study of myocardial perfusion with microbubbles contrast echocardiography. METHODS: 81 pts (64 male, 60+11 years) were submitted to contrast echocardiography with PESDA (sonicated solution of albumin 20%-1ml, dextrose 5%-12ml and deca-fluorobutane gas-8ml) to study the myocardial perfusion at rest and after bolus injection of adenosine (6 to 18mg) and to coronary angiography within 1 month each other. For each patient 3 left ventricle perfusion beds were considered (total of 243 territories). 208 territories were analyzed and 35 territories were excluded. PESDA was continuously infused (1-2ml/min), titrated for best myocardial contrast. Triggered (1:1) second harmonic imaging was used. RESULTS: Coronary angiography showed 70 flow limiting (> 75%) lesions and 138 no flow limiting lesions. At rest an obvious myocardium contrast enhancement was seen in at least 1 segment of a territory in all patients. After adenosine injection an unquestionable further increase in myocardial contrast was observed in 136 territories (99%) related to no flow limiting lesions, lasting < 10 s, and a myocardial perfusion defect was detected in 68 territories (97%) related to flow limiting lesions. It was observed only 4 false results. There were no serious complications. CONCLUSION: Myocardial perfusion study with PESDA and adenosine protocol is a practical, safe and accurate method to analyze the coronary flow reserve.

Antibacterial properties of multifunctional coatings Ag-ZrCN for biomedical devices: a novel approach

PhD in Sciences Specialty in Physics

Operation modes for the electric vehicle in smart grids and smart homes : present and proposed modes

This paper presents the main operation modes for an electric vehicle (EV) battery charger framed in smart grids and smart homes, i.e., are discussed the present-day and are proposed new operation modes that can represent an asset towards EV adoption. Besides the well-known grid to vehicle (G2V) and vehicle to grid (V2G), this paper proposes two new operation modes: Home-to-vehicle (H2V), where the EV battery charger current is controlled according to the current consumption of the electrical appliances of the home (this operation mode is combined with the G2V and V2G); Vehicle-for-grid (V4G), where the EV battery charger is used for compensating current harmonics or reactive power, simultaneously with the G2V and V2G operation modes. The vehicle-to-home (V2H) operation mode, where the EV can operate as a power source in isolated systems or as an off-line uninterruptible power supply to feed priority appliances of the home during power outages of the electrical grid is presented in this paper framed with the other operation modes. These five operation modes were validated through experimental results using a developed 3.6 kW bidirectional EV battery charger prototype, which was specially designed for these operation modes. The paper describes the developed EV battery charger prototype, detailing the power theory and the voltage and current control strategies used in the control system. The paper presents experimental results for the various operation modes, both in steady-state and during transients.

Microwave imaging of high-contrast objects

Imaging microwave reconstruction dielectric contrast regularization iterative multiport cavity measurement

Chromatic responses in human visual cortex : effects of color, velocity and contrast

fMRI, color, colour, velocity, speed, contrast, cone contrast, V1, V4, hV4, MT, MT+, V3A, BOLD, Retinotopic Mapping, Contrast Response Function

When is the Best Time for the Second Antiplatelet Agent in Non-St Elevation Acute Coronary Syndrome?

Abstract Dual antiplatelet therapy is a well-established treatment in patients with non-ST elevation acute coronary syndrome (NSTE-ACS), with class I of recommendation (level of evidence A) in current national and international guidelines. Nonetheless, these guidelines are not precise or consensual regarding the best time to start the second antiplatelet agent. The evidences are conflicting, and after more than a decade using clopidogrel in this scenario, benefits from the routine pretreatment, i.e. without knowing the coronary anatomy, with dual antiplatelet therapy remain uncertain. The recommendation for the upfront treatment with clopidogrel in NSTE-ACS is based on the reduction of non-fatal events in studies that used the conservative strategy with eventual invasive stratification, after many days of the acute event. This approach is different from the current management of these patients, considering the established benefits from the early invasive strategy, especially in moderate to high-risk patients. The only randomized study to date that specifically tested the pretreatment in NSTE-ACS in the context of early invasive strategy, used prasugrel, and it did not show any benefit in reducing ischemic events with pretreatment. On the contrary, its administration increased the risk of bleeding events. This study has brought the pretreatment again into discussion, and led to changes in recent guidelines of the American and European cardiology societies. In this paper, the authors review the main evidence of the pretreatment with dual antiplatelet therapy in NSTE-ACS.

Long memory model of resting state functional MRI

Magdeburg, Univ., Fak. für Elektrotechnik und Informationstechnik, Diss., 2013

Weiterentwicklung von OpenSSL.NET als Schnittstelle zwischen der freien OpenSSL-Bibliothek und dem .NET Framework für den Einsatz in Smart Metering Systemen

[s.c.]

Multi-echo radial FLASH techniques for real-time MRI

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2015

A model-based cortical parcellation scheme for high-resolution 7 Tesla MRI data

Magdeburg, Univ., Fak. für Informatik, Diss., 2015

Implementation of the ordinal shapley value for a three-agent economy

We propose a simple mechanism that implements the Ordinal Shapley Value (Pérez-Castrillo and Wettstein [2005]) for economies with three or less agents.

The Instrumental voter goes to the news-agent: demand for information, election closeness, and the media

This paper studies the impact of instrumental voting on information demand and mass media behaviour during electoral campaigns. If voters act instrumentally then information demand should increase with the closeness of an election. Mass media are modeled as profit-maximizing firms that take into account information demand, the value of customers to advertisers and the marginal cost of customers. Information supply should be larger in electoral constituencies where the contest is expected to be closer, there is a higher population density, and customers are on average more profitable for advertisers. The impact of electorate size is theoretically undetermined. These conclusions are then tested with comfortable results on data from the 1997 general election in Britain.

The principal-agent matching market

We propose a model based on competitive markets in order to analyze an economy with several principals and agents. We model the principal-agent economy as a two-sided matching game and characterize the set of stable outcomes of this principal-agent matching market. A simple mechanism to implement the set of stable outcomes is proposed. Finally, we put forward examples of principal-agent economies where the results fit into.

Incorporació del català en agent conversacional animat per computador

Dins del marc del projecte europeu HERMES, al Centre de Visió per Computador de la Universitat Autònoma de Barcelona s'està desenvolupant un agent conversacional animat per ordinador el qual haurà de ser capaç d'interactuar amb l'usuari a través de diferents canals de forma simultània, o, el que és el mateix, parlar, gesticular, expressar emocions... Partint, doncs, d'un software capaç de fer que un model 3D d'un cap humà expressi emocions i parli en anglès, donat un arxiu d'àudio prèviament generat, en el treball que aquí es presenta es duu a terme la recerca d'una eina sintetitzadora de parla a partir de text que permeti fer això mateix en català. En aquest document s'explica el procés seguit per a trobar aquesta eina, la investigació realitzada sobre el funcionament d'ambdues per tal d'entendre-les i poder-hi treballar, així com, finalment, les modificacions realitzades per a fer que aquestes puguin interactuar i generar parla inteligible en català a partir de textos escrits en aquest idioma.