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Search Results: 1 - 10 of 300 matches for " NICOLOSI Denys "
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Testes in vitro e in vivo com o Cora o Artificial Auxiliar (CAA): um novo modelo de cora o artificial totalmente implantável e heterotópico
Revista Brasileira de Cirurgia Cardiovascular , 1999,
Abstract: Um novo modelo de cora o artificial está sendo desenvolvido e testado em nossos laboratórios, o Cora o Artificial Auxiliar (CAA). Este dispositivo foi projetado com dimens es reduzidas para ser implantado em paralelo ao cora o natural do paciente, dentro da cavidade torácica direita de forma heterotópica. Foram realizados testes in vitro, em um circuito simulador do sistema circulatório humano, para verifica o do desempenho hidrodinamico do CAA. Os resultados mostraram que o CAA pode fornecer um fluxo de até 5,8 L/min, com uma pré-carga de 20 mmHg e uma pós-carga de 100 mmHg. A freqüência de batimento do CAA e, consequentemente, o débito cardíaco s o dependentes da pré-carga do ventrículo esquerdo, funcionamento semelhante ao cora o natural (Lei de Frank Starling). Testes in vivo animal est o sendo realizados para avaliar os resultados obtidos com os testes in vitro e para verificar o comportamento do CAA em ambiente e condi es fisiológicas difíceis de serem simuladas. Os testes in vivo est o sendo também importantes para o desenvolvimento de técnicas cirúrgicas e treinamento dos cirurgi es cardiovasculares envolvidos no projeto. Até o momento, dois estudos agudos in vivo foram realizados, com o CAA funcionando por 5h, implantado na cavidade torácica direta de carneiros adultos (50 ± 5 kg). Os resultados destes estudos in vivo demonstraram que o funcionamento do CAA é sincronizado ao cora o natural, sendo possível estudar o comportamento do CAA quando, gradativamente, o cora o natural teve sua contratilidade reduzida até sua parada total.
Análise do desempenho de um eletrocardiógrafo interpretativo para utiliza??o em um sistema computacional de auxílio diagnóstico em síndromes coronarianas agudas
Freitas Junior, Manoel Gadêlha de;Nicolosi, Denys Emilio Campion;Fran?a, Francisco Faustino de Albuquerque Carneiro de;
Revista Brasileira de Engenharia Biomédica , 2012, DOI: 10.4322/rbeb.2012.019
Abstract: the electrocardiogram (ecg) is the recording of the heart's electrical activity from the surface of the body and has been worldwide used in routine medical practice since the last century. this is a first-rate tool for a rapid interpretation of cardiac rhythm and for assessment and immediate therapeutic management in patients with suspected acute coronary syndrome, which is a clinical entity that includes unstable angina and acute myocardial infarction with and without st-segment elevation. currently, electrocardiographs from various manufacturers are capable of providing automatic diagnosis of ecgs, but there are few published studies about the performance of these equipments. the objective of this paper is to evaluate the performance of an interpretive electrocardiograph in order to determine their suitability for use in a computer system that uses the medical history information obtained by the general practitioner and the electrocardiographic report emitted by the equipment evaluated to aid the diagnosis of acute coronary syndromes, when the patient is not treated by cardiologists. we used an interpretive electrocardigraph nihon kohden cardiofax 9620. the electrocardiograph simulator metron ps 420 was the choice for the simulated tests, and also we compared the performance of the cardiofax with a telemedicine system available in a semi-rural area in brazil. the tests resulted in 93.8% sensitivity and 83.3% specificity that were considered satisfactory in clinical situations compatible with acute myocardial ischemia, validating their use in an artificial intelligence system for the diagnosis of acs.
Estudo comparativo das características fluidodinamicas de próteses valvulares biológicas de pericárdio bovino de perfil alto e baixo
Andrade, Aron J. P;Biscegli, José F;Nicolosi, Denys E;Gómez, Hernán C;Sousa, J. Eduardo M. R;
Revista Brasileira de Cirurgia Cardiovascular , 1989, DOI: 10.1590/S0102-76381989000300008
Abstract: the fluid dynamic performance and lifetime of a prosthetic heart valve are one of the most important characteristics to determine the choice of what prosthesis must be applied to a patient. because of this, two different biological prosthetic heart valves profiles (one high profile and other low profile) were studied, to verify possible alterations of working life, pressure gradient and reverse flux debt to this profiles difference. with a pulse duplication, ten valves sixe 29 were analysed , manufactured by institute dante pazzanese de cardiologia, being five low profile and five high profile. with a working frequency of 1000 ppm (pulses per minute) and a differential pressure of 1000 mmhg, we verified the same working life in both cases. with a cardiac simulator, the prosthesis was submitted to similar physiologic human cardiac conditions, with an equivalent 75 ppm heart pulse. the results show that the reverse flux volume necessary to close the low profile valve is lower than with the high profile valve. the loss head of these valves were compared though the maximum pressure gradient of them. it was noticed that the low profile, biological prosthetic valves are lower flux resistant than the high profile valves, being then more indicated to its implant function.
Testes in vitro e in vivo com o Cora??o Artificial Auxiliar (CAA): um novo modelo de cora??o artificial totalmente implantável e heterotópico
ANDRADE, Aron;OHASHI, Yukio;LUCCHI, Júlio;NICOLOSI, Denys;DINKHUYSEN, Jarbas J.;BISCEGLI, José;ARRUDA, Ant?nio C. F.;CUNHA, Wagner C.;NOSé, Yukihiko;
Revista Brasileira de Cirurgia Cardiovascular , 1999, DOI: 10.1590/S0102-76381999000200010
Abstract: a miniaturized artificial heart is being developed in the authors laboratories, the auxiliary total artificial heart (atah). this device is an electromechanically driven atah using a brushless direct current (dc) motor fixed in a center aluminum piece. this pusher plate type atah is controlled based on frank-starling's law. the beating frequency is regulated through the change of the left preload, assisting the natural heart in obtaining adequate blood flow. with the miniaturization of this pump, the average sized patient can have the surgical procedure of implantation in the right thoracic cavity performed without removal of the natural heart. the left and right stroke volumes are 35 ml and 32 ml, respectively. in vitro tests were made and the performance curves demonstrated that the atah produces 5l/min of cardiac output at 180 bpm (10 mmhg of left inlet mean pressure and 100 mmhg of left outlet mean pressure). preliminary acute in vivo tests were performed in two sheeps with 50 ± 5 kg, during 5 hours. the atah performance is satisfactory for helping the natural heart to obtain the required blood flow and arterial pressure. with the atah and the natural heart working simultaneously the atah control system is simpler, also the risks of a fatal misoperation is minor compared to a total artificial heart, for patients that still present some cardiac function.
A. Nicolosi
Jurnalul de Chirurgie , 2010,
Abstract: The main complications after total thyroidectomy are less and include bleeding, injuries of recurrent laryngeal nerves (RLN) and hypoparathyroidism. Modern technologies increase a quality of thyroid surgery. Accurate hemostasis is basic to prevent bleeding. Harmonic Focus is an ultrasonic scalpel that performs dissection, hemostasis and cut with small lateral thermal injuries. Harmonic Focus decrease operative time, hospital stay, postoperative drainage and postoperative hypoparathyroidism. Intraoperative RLN injury causes are section (mistake in surgical technique); ligature (without transection); mistake in haemostasis and dissection manoeuvres; stretch/traction; excessive traction during the medial traction of the thyroid lobe; excessive aspiration near to the nerve (suction); compression/contusion/pressure; thermal/electrical injury; diffusion by haemostatic devices; ischemia; ligation of the inferior pole vessels before identifying RLN; excessive dissection of the nerve with ischemia. Evolution of RLN monitoring was from intra-operative invasive techniques to non-invasive surface electrodes (endotracheal tube). Positive acoustic signal following stimulation of the vague nerve and the RLN always means: vocalis muscle is intact and positive acoustic signal only by RLN stimulation usually means: RLN paresis (nerve lesion distal to the stimulation site). The correlation between a positive acoustic signal and a postoperatively intact vocal function is very high (97%). The use of the nerve monitoring can be recommended as useful, but not generally demanded as obligatory.
An Operator-Based Exact Treatment of Open Quantum Systems
S. Nicolosi
Physics , 2005,
Abstract: "Quantum mechanics must be regarded as open systems. On one hand, this is due to the fact that, like in classical physics, any realistic system is subjected to a coupling to an uncontrollable environment which influences it in a non-negligible way. The theory of open quantum systems thus plays a major role in many applications of quantum physics since perfect isolation of quantum system is not possible and since a complete microscopic description or control of the environment degrees of freedom is not feasible or only partially so" [1]. Practical considerations therefore force one to seek for a simpler, effectively probabilistic description in terms of an open system. There is a close physical and mathematical connection between the evolution of an open system, the state changes induced by quantum measurements, and the classical notion of a stochastic process. The paper provides a bibliographic review of this interrelations, it shows the mathematical equivalence between markovian master equation and generalized piecewise deterministic processes [1] and it introduces the open system in an open observed environment model.
Imaging Metabolico Al Carbonio 13 Iperpolarizzato: Stato Dell'arte
Stefania Nicolosi
Physics , 2011,
Abstract: Magnetic Resonance Imaging (MRI) can be considered one of the most effective techniques in both clinical diagnostic medical field and biomedicine, as it allows to obtain images anatomy of the body and its various parts and information functional, such as flow, perfusion, diffusion, motion, etc.. It is based on the interaction of nuclei with magnetic spin number different from zero with the magnetic field outside and, in theory, could be used for the analysis of different nuclei, such as 1H, 13C, 31P (endogenous) or 129 Xe, 3He (Exogenous). In practice, however, the clinical use of MRI is limited analysis of 1H that, compared to the others, manifest the highest concentration in the human body. The use of contrast media usually lengthens the execution time of an examination of MRI. These, however, would greatly directly reduce by increasing the intensity of the substrate signal. This can be achieved through an increase in the substrate polarization via the creation of an equilibrium state where the population difference between levels is increased. This state is called hyperpolarized. In recent years have been designed and developed several techniques for achieving this goal. Hyperpolarized contrast agents therefore act very differently from classical ones, because, instead of modifying the signal due the protons surrounding themselves, become themselves a source of signal. In order to be functional such contrast agents should be characterized by a high longitudinal relaxation time T1, because the hyperpolarized state must remain as long as possible after injection into the circulatory system of the patient.
Potential Cost Savings from Generic Medicines - Protecting the Prescribed Minimum Benefits
E Nicolosi, A Gray
South African Family Practice , 2009,
Abstract: Background: South Africa has followed a pro-generic policy since the introduction of the National Drug Policy in 1996. The selection processes in the public and private sectors have, however, remained largely disconnected, and at times contradictory. Medicines provided outside of hospitals accounted for 17% of medical aid spend in 2006, up 8.8% from the previous year. Of particular concern to funders has been the expenditure on the 27 chronic conditions listed as Prescribed Minimum Benefits. The Medical Schemes Act (No 131 of 1998) provides for the definition of Prescribed Minimum Benefits, which stipulate a package of services or care a medical scheme must provide for in its benefit design. There is pressure to reconsider these requirements in order to increase the affordability of medical scheme coverage. This study assessed the potential savings that would be achievable by substituting generics for brand name (originator) medicines listed in the chronic disease algorithms set out by the Council for Medical Schemes (CMS). Methods: All medicines listed in the 25 chronic diseases algorithms made available by the CMS were identified. Brand and generic versions were identified in the Monthly Index of Medical Specialties (MIMS, May 2006). Single exit prices inclusive of value added tax were obtained from the web site of the Pharmaceutical Blue Book and the cost per defined daily dose for one month was then calculated. Cost differentials, where available, were then identified for each medicine listed in the algorithms. Cost differentials for medicines within each algorithm were presented as the median of the difference between brand and generic medicines listed for that algorithm, and also as the median of differences between generic medicines for the same condition. Results: Three of the algorithms (diabetes insipidus, haemophilia and hypothyroidism) list medicines for which no generic equivalent was available at the time of the study. The median cost differential between brand and generic equivalents for the remaining 22 chronic conditions ranged from 19.5% (for type 1 diabetes mellitus) to 97% (for Addison’s disease). Across the entire chronic disease algorithm set, 80 medicines with generic equivalents were listed for 22 conditions. The median cost differential between brand and generic versions of these 80 medicines was 49.9% (interquartile range 32.0 to 78.5%). Of all generic medicines identified, 67.5% were more than 40% cheaper, per defined daily dose (DDD) per month, than the branded version. In 16 medicines the cost differentials between generic versions were 1% or less. Some correlation between the number of generics and the size of the cost differential was apparent (correlation coefficient 0.49). There were examples of high-cost differentials in highly competitive areas of the market. Conclusions: An argument could be made for more closely aligning the process of developing the National Essential Drugs List and the development of the CMS
Il paesaggio terrazzato della Costa Viola
Agata Nicolosi,Domenico Cambareri
Aestimum , 2007,
Abstract: Il paesaggio terrazzato della Costa Viola
On the Sets of Regularity of Solutions for a Class of Degenerate Nonlinear Elliptic Fourth-Order Equations with L1 Data
S. Bonafede,F. Nicolosi
Boundary Value Problems , 2007, DOI: 10.1155/2007/65825
Abstract: We establish H lder continuity of generalized solutions of the Dirichlet problem, associated to a degenerate nonlinear fourth-order equation in an open bounded set ¢ ¢ n, with L1 data, on the subsets of where the behavior of weights and of the data is regular enough.
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