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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Komplexní ošetřovatelská péče u pacienta po transplantaci plic na anesteziologicko resuscitačním oddělení. / Complex nursing care for patient after lung transplant at Anesthesiology resuscitation department.

Ivánková, Vendula January 2018 (has links)
Lungs transplantation is a solution for the end stage of pulmonary disease after other therapeutic possibilities that the modern medicine has to offer have been exhausted. The main objective of this thesis is to show postoperative patient care after lung transplantation in the department anesthesiology and resuscitation. A highly specialized complex care and cooperation of various fields is needed. Nurses who take care of these patients must be experienced and skillful. They also need to manage well the nursing care for patients in sedation as well as fully conscious patents. It is also needed that the nurses are acquainted with specialized methods of hemodynamics measurements, administration of nitrous oxide and operation of extracorporeal membrane oxygenation machine. They need to know well the drugs that are being administered. The thesis summarizes anatomy and physiology of respiratory system, it deals with lung disease and their symptoms which most often lead to lung transplantation. Finally, the thesis describes the development of lung transplantation from its beginning to the present including the number of cases of lung transplantation per year. The last chapter of the theoretical part also shows indication, contraindication and the main principles of patient care that is given prior to and...
192

Faisabilité de l'écho-Doppler de la veine hépatique dans un département d’urgence

Omakinda Luhaka, Rémy 03 1900 (has links)
Au sein des unités de médecine d'urgence, l'état de choc est une condition courante et par le fait même, une cause majeure de mortalité en Amérique du nord. Il est donc essentiel d'en rechercher rapidement les causes. Dans cette recherche, l'évaluation clinique, l'examen des signes vitaux et les tests de laboratoire se révèlent souvent imprécis car ils ne permettent pas d'évaluer de façon optimale le statut hémodynamique des patients instables. Or, le risque d'une évaluation insuffisante de l’état hémodynamique conduit à l'instauration d'un traitement inapproprié dont la conséquence peut être fatale. Une simple surestimation du besoin de remplissage vasculaire peut entraîner des complications telles que l'œdème pulmonaire et inversement, la sous-estimation peut avoir pour conséquence une hypovolémie persistante avec une hypoperfusion ou un état de choc non reconnu susceptible de générer une insuffisance des organes cibles. Actuellement, pour évaluer le statut hémodynamique, les méthodes les plus utilisées sont la pression veineuse centrale (PVC), les cathéters de Swan-Ganz et l’échocardiographie transoesophagienne. Bien que déjà difficiles à réaliser à l’urgence, toutes ces méthodes sont invasives et conservent un potentiel élevé de morbidité. Il existe toutefois des méthodes alternatives valides qui permettent d'obtenir une estimation non invasive de la pression moyenne de l'oreillette droite, entre autre l’échographie sous-costale avec les mesures échographiques de la collapsibilité de la veine cave inférieure (VCI) et les mesures de Doppler échographiques sur la veine hépatique (VH). Il convient cependant de noter que la mesure de la collapsibilité de la VCI n’a pas réussi à devenir un standard d’évaluation de la volémie parce qu’elle reste sujette à plusieurs facteurs confondants.   La mesure du flot de la VH, quant à elle, semble être une option plus intéressante pour mieux évaluer la pression de remplissage de l’oreillette droite. En effet, l'échographie Doppler de la veine hépatique reste donc un instrument potentiellement prometteur qui peut bien refléter les pressions de l’OD et donc de la pression veineuse centrale. Il importe de souligner que pour le patient instable, chaque minute est précieuse et qu’un gain de temps inestimable contribue à éliminer les facteurs susceptibles de compromettre le pronostic vital. L’objectif principal de notre étude, étant la mesure du temps nécessaire pour l’acquisition d’images ; nous avons comparé la durée de l'acquisition d'images entre l'échographie de la VCI et le Doppler de la VH chez des sujets sains. Le temps moyen d'acquisition d'images de la VCI était de 89,1 secondes et de 117,8 pour la VH. La différence de la moyenne de temps était de 28,6 secondes (IC95% -73,2 · +15,8 ; t=1.33, 24 dl ; p=0.196). La différence de délai pour le temps d’acquisition d’images était inférieure à 30 secondes. En pratique, nous pensons que cette différence peut être considérée comme cliniquement acceptable pour une prise de décision rapide. En ce qui concerne le taux d’échec entre les deux techniques, nous n’avons pas trouvé de différence significative : 1 échec pour la VCI et 5 échecs pour la VH avec une différence de 13% (0.133), p=0.09 ; alors que le taux de réussite est le même, soit 25 pour chacune. L’évaluation de la veine hépatique par échographie était faisable, simple et rapide dans la majorité des volontaires sélectionnés dans notre étude. Mots-clés : échographie Doppler, veine cave inférieure, veines hépatiques, état de choc, statut hémodynamique. / Shock is a common condition and a major cause of death in emergency units. Clinical evaluation, vital signs and laboratory tests can lack specificity to identify the cause of shock and do not allow an optimal evaluation of the hemodynamic status of unstable patients. A poor evaluation of the hemodynamic state could lead to inappropriate treatment and the consequence may be fatal. Overestimation of the need for vascular filling can lead to complications such as pulmonary edema; while underestimation may give rise to persistent hypovolemia with hypoperfusion or unrecognized shock resulting in multi-organ failure. The current methods used to assess hemodynamic status are central venous pressure, Swan-Ganz catheters, and trans-esophageal echocardiography. Although already difficult to perform in the emergency department, all of these methods are invasive and retain a high potential for morbidity. However, there are valid alternative methods for obtaining a non-invasive estimate of the average pressure of the right atrium, including subxiphoid ultrasound with measurements of the inferior vena cava (IVC) collapsibility and ultrasound Doppler measurements of the hepatic veins (HV). However, the measurement of the collapsibility of the IVC is subject to several confounding factors and has failed to become a standard of care for evaluating patients’ volemic status. Measuring the flow of the hepatic vein, on the other hand, seems to be a more interesting option for better assessing the filling pressure of the right atrium. Indeed, the Doppler ultrasound of hepatic veins remains a potentially promising instrument that may well reflect the pressures of the right atrium and thus of the central venous pressure. It is important to emphasize that for the unstable patient, every minute is precious and that saving time contributes to eliminate factors likely to compromise the vital prognosis.   The main objective of our study is to measure the time it takes to acquire images. We compared the duration of image acquisition between IVC ultrasound and HV Doppler in healthy volunteers. The average image acquisition time for the IVC and HV was 89.1 and 117.8 seconds respectively. The difference in mean time was 28.6 seconds (95% CI -73.2 · + 15.8, t = 1.33, 24 dL, p = 0.196). The difference for image acquisition time was less than 30 seconds. In practice, we believe that this difference can be considered clinically acceptable for rapid decision-making. Regarding the failure rate between the two techniques, we did not find any significant difference: 1 failure for IVC and 5 failures for HV with a difference of 13% (0.133), p = 0.09; while the success rate is the same, 25 for each. The evaluation of the hepatic vein by ultrasonography was feasible, simple and fast in the majority of volunteers selected in our study. Key words: Doppler ultrasonography, inferior vena cava, hepatic veins, shock, hemodynamic status
193

Intraoperative hemodynamic instability during and after separation from cardiopulmonary bypass : importance, mechanism and prevention

Denault, André 09 1900 (has links)
Chaque année, environ 1 à 1,25 million d’individus subiront une chirurgie cardiaque. [1] Environ 36 000 chirurgies cardiaques sont effectuées au Canada et 8000 procédures au Québec (http://www.ccs.ca). Le vieillissement de la population aura pour conséquence que la chirurgie cardiaque sera offerte à des patients de plus en plus à risque de complications, principalement en raison d’une co-morbidité plus importante, d’un risque de maladie coronarienne plus élevée, [2] d’une réserve physiologique réduite et par conséquent un risque plus élevé de mortalité à la suite d’une chirurgie cardiaque. L’une des complications significatives à la suite d’une chirurgie cardiaque est le sevrage difficile de la circulation extracorporelle. Ce dernier inclut la période au début du sevrage de la circulation extracorporelle et s’étend jusqu’au départ du patient de la salle d’opération. Lorsque le sevrage de la circulation extracorporelle est associé à une défaillance ventriculaire droite, la mortalité sera de 44 % à 86 %. [3-7] Par conséquent le diagnostic, l’identification des facteurs de risque, la compréhension du mécanisme, la prévention et le traitement du sevrage difficile de la circulation extracorporelle seront d’une importance majeure dans la sélection et la prise en charge des patients devant subir une chirurgie cardiaque. Les hypothèses de cette thèse sont les suivantes : 1) le sevrage difficile de la circulation extracorporelle est un facteur indépendant de mortalité et de morbidité, 2) le mécanisme du sevrage difficile de la circulation extracorporelle peut être approché d’une façon systématique, 3) la milrinone administrée par inhalation représente une alternative préventive et thérapeutique chez le patient à risque d’un sevrage difficile de la circulation extracorporelle après la chirurgie cardiaque. / Every year, 1 million to 1.25 million patients worldwide undergo cardiac surgery. [1] Up to 36,000 cardiac surgeries are performed each year in Canada and close to 8000 in Quebec (http://www.ccs.ca). Because of the aging of the population, cardiac surgery will increasingly be offered to patients at a higher risk of complications. Indeed, elderly patients have increased co-morbidities, and aging is also a significant risk factor in the prevalence of coronary artery disease. [2] The consequence is a reduced physiologic reserve, hence an increased risk of mortality. These issues will have a significant impact on future healthcare costs, because our population undergoing cardiac surgery will be older and more likely to develop postoperative complications. One of the most dreaded complications in cardiac surgery is difficult separation from cardiopulmonary bypass (CPB). The definition of difficult separation from CPB includes the time period from when CPB is initiated and until the patient leaves the operating room. When separation from CPB is associated with right ventricular failure, the mortality rate will range from 44% to 86%. [3-7] Therefore the diagnosis, the preoperative prediction, the mechanism, prevention and treatment of difficult separation from CPB will be crucial in order to improve the selection and care of patients and to prevent complications for this high-risk patient population. The hypotheses of this thesis are the following: 1) difficult separation from CPB is an independent factor of morbidity and mortality, 2) the mechanism of difficult separation from CPB can be understood through a systematic approach, 3) inhaled milrinone is a preventive and therapeutic approach in the patient at risk for difficult weaning from CPB after cardiac surgery.
194

Effects of Shear Stress on the Distribution of Kindlins in Endothelial Cells

Jones, Sidney V. 29 May 2014 (has links)
No description available.
195

An investigation of fMRI-based perfusion biomarkers in resting state and physiological stimuli

Jinxia Yao (13925085) 10 October 2022 (has links)
<p>    </p> <p>Cerebrovascular diseases, such as stroke, constitute the most common life-threatening neurological disease in the United States. To support normal brain function, maintaining adequate brain perfusion (i.e., cerebral blood flow (CBF)) is important. Therefore, it is crucial to assess the brain perfusion so that early intervention in cerebrovascular diseases can be applied if abnormal perfusion is observed. The goal of my study is to develop metrics to measure the brain perfusion through modeling brain physiology using resting-state and task-based blood-oxygenation-level- dependent (BOLD) functional MRI (fMRI). My first and second chapters focused on deriving the blood arrival time using the resting-state BOLD signal. In the first chapters, we extracted the systemic low-frequency oscillations (sLFOs) in the fMRI signal from the internal carotid arteries (ICA) and the superior sagittal sinus (SSS). Consistent and robust results were obtained across 400 scans showing the ICA signals leading the SSS signals by about 5 seconds. This delay time could be considered as an effective perfusion biomarker that is associate with the cerebral circulation time (CCT). To further explore sLFOs in assessing dynamic blood flow changes during the scan, in my second chapter, a “carpet plot” (a 2-dimensional plot time vs. voxel) of scaled fMRI signal intensity was reconstructed and paired with a developed slope-detection algorithm. Tilted vertical edges across which a sudden signal intensity change took place were successfully detected by the algorithm and the averaged propagation time derived from the carpet plot matches the cerebral circulation time. Given that CO<sub>2</sub> is a vasodilator, controlling of inhaled CO<sub>2</sub> is able to modulate the BOLD signal, therefore, as a follow-up study, we focused on investigating the feasibility of using a CO<sub>2</sub> modulated sLFO signal as a “natural” bolus to track CBF with the tool developed from the second chapter. Meaningful transit times were derived from the CO<sub>2</sub>-MRI carpet plots. Not only the timing, the BOLD signal deformation (the waveform change) under CO<sub>2</sub> challenge also reveals very useful perfusion information, representing how the brain react to stimulus. Therefore, my fourth chapter focused on characterizing the brain reaction to the CO<sub>2</sub> stimulus to better measure the brain health using BOLD fMRI. Overall, these studies deepen our understanding of fMRI signal and the derived perfusion parameters can potentially be used to assess some cerebrovascular diseases, such as stroke, ischemic brain damage, and steno-occlusive arterial disease in addition to functional activations. </p>
196

Développement d’un système de Topographie Optique Diffuse résolu en temps et hyperspectral pour la détection de l’activité cérébrale humaine / Developement of a hyperspectral time resolved DOT system for the monitoring of the human brain activity

Lange, Frédéric 28 January 2016 (has links)
La Tomographie Optique Diffuse (TOD) est désormais une modalité d’imagerie médicale fonctionnelle reconnue. L’une des applications les plus répandues de cette technique est celle de l’imagerie fonctionnelle cérébrale chez l’Homme. En effet, cette technique présente de nombreux avantages, notamment grâce à la richesse des contrastes optiques accessibles. Néanmoins, certains verrous subsistent et freinent le développement de son utilisation, spécialement pour des applications chez l’Homme adulte en clinique ou dans des conditions particulières comme lors du suivi de l’activité sportive. En effet, le signal optique mesuré contient des informations venant de différentes profondeurs de la tête, et donc de différents types de tissus comme la peau ou le cerveau. Or, la réponse d’intérêt étant celle du cerveau, la réponse de la peau peut dégrader l’information recherchée. Dans ce contexte, ces travaux portent sur le développement d’un nouvel instrument de TOD permettant d’acquérir les dimensions spatiale, spectrale et de temps de vol du photon de façon simultanée, et ce à haute fréquence d’acquisition. Au cours de cette thèse, l’instrument a été développé et caractérisé sur fantôme optique. Ensuite, il a été validé in-vivo chez l’Homme adulte, notamment en détectant l’activité du cortex préfrontal en réponse à une tâche de calcul simple. Les informations multidimensionnelles acquises par notre système ont permis d’améliorer la séparation des contributions des différents tissus (Peau/Cerveau). Elles ont également permis de différencier la signature de la réponse physiologique de ces tissus, notamment en permettant de détecter les variations de concentration en Cytochrome-c-oxydase. Parallèlement à ce développement instrumental, des simulations Monte-Carlo de la propagation de la lumière dans un modèle anatomique de tête ont été effectuées. Ces simulations ont permis de mieux comprendre la propagation de la lumière dans les tissus en fonction de la longueur d’onde et de valider la pertinence de cette approche multidimensionnelle. Les perspectives de ces travaux de thèse se dirigent vers l’utilisation de cet instrument pour le suivi de la réponse du cerveau chez l’Homme adulte lors de différentes sollicitations comme des stimulations de TDCS, ou en réponse à une activité sportive. / The Diffuse Optical Tomography (DOT) is now a relevant tool for the functional medical imaging. One of the most widespread application of this technic is the imaging of the human brain function. Indeed, this technic has numerous advantages, especially the richness of the optical contrast accessible. Nevertheless, some drawbacks are curbing the use of the technic, especially for applications on adults in clinics or in particular environment like in the monitoring of sports activity. Indeed, the measured signal contains information coming from different depths of the head, so it contains different tissues types like skin and brain. Yet, the response of interest is the one of the brain, and the one of the skin is blurring it. In this context, this work is about the development of a new instrument of DOT capable of acquiring spatial and spectral information, as well as the arrival time of photons simultaneously and at a high acquisition speed. During the PhD thesis the instrument has been developed and characterised on optical phantoms. Then, it has been validated in-vivo on adults, especially by detecting the cortical activation of the prefrontal cortex, in response to a simple calculation task. Multidimensional information acquired by our system allowed us to better distinguish between superficial and deep layers. It also allowed us to distinguish between the physiological signature of those tissues, and especially to detect the variations of concentration in Cytochrom-c-oxydase. Concurrently to this experimental work, Monte-Carlo simulation of light propagation in a model off a human head has been done. Those simulations allowed us to better understand the light propagation in tissues as function as their wavelength, and to validate the relevance of our multidimensional approach. Perspectives of this work is to use the developed instrument to monitor the brain’s response of the Human adult to several solicitations like tDCS stimulation, or sports activity.
197

L’évaluation des déterminants des paramètres hémodynamiques centraux à l’aide de la cohorte populationnelle CARTaGENE

Goupil, Rémi 04 1900 (has links)
No description available.
198

Fluidoresponsividade em pacientes críticos sob ventilação mecânica: da pressão venosa central para ecocardiografia à beira leito / Fluoresponsiveness in critically ill patients under mechanical ventilation: from central venous pressure to bedside echocardiography

Livia Maria Ambrósio da Silva, Livia 21 July 2017 (has links)
Introdução: Prever a capacidade de resposta a fluidos continua sendo um desafio para os médicos que lidam com pacientes instáveis hemodinamicamente. A utilização de parâmetros estáticos, como pressão venosa central (PVC) tem sido usada por décadas, mas não é confiável, evidências robustas sugerem que seu uso deve ser abandonado. Ao longo dos últimos 15 anos, foram desenvolvidos vários testes dinâmicos, baseados no princípio de alteração da pré-carga cardíaca, usando as interações coração-pulmão, e, consequentemente do débito cardíaco. A elevação passiva das pernas (EPP), a infusão de pequenos volumes de fluidos, a variação da pressão de pulso (ΔPP), as variações nos diâmetros de grandes veias tem sido muito utilizados para avaliação de fluidoresponsividade (FR), neste contexto. Objetivo: Analisar e comparar medidas estáticas e dinâmicas antes, após EPP e após infusão de SF, verificando qual delas apresentam melhor FR. Métodos: Trinta e um pacientes instáveis hemodinamicamente e sob ventilação mecânica (VM) foram incluídos no estudo. Foram avaliados VTIFAO, VTIFMi, IDVCI, ΔPP, PVC, PAM antes de qualquer intervenção, após EPP e após infusão de 500ml SF. As variações dos parâmetros foram calculados para todos os pacientes. Resultados: Após EPP e infusão de SF o VTIFAO aumentou em 10% ou mais em 14 (45%) e 18 (58%) pacientes respectivamente, definidos como FR. A EPP previu a capacidade de resposta a fluidos com uma sensibilidade de 77,7%, especificidade de 100%, valor preditivo positivo de 100% e probabilidade de falso positivo de 0%. O parâmetro utilizado como padrão para FR foi o VTIFAO após SF. A PVC, o IDVCI, o ΔPP, PAM e avaliação médica não se mostraram capazes de avaliar adequadamente FR. Conclusão: Em pacientes instáveis hemodinamicamente e sob VM, a EPP foi capaz de avaliar FR com adequada sensibilidade e especificidade, podendo ser usada com segurança, antes da administração de fluidos. / Introduction: Predictig fluid responsiveness remains a constant challenge for physicians dealing with hemodynamically unstable patients. The use of static parameters, such as central venous pressure (CVP), although used for decades is not a trustworthy source, and the suggestion derived from more robust evidence suggests that the use of such should be abandoned. Over the last 15 years, various dynamic tests have been developed based on the principle of altering the cardiac preload, by using the heart-lung interactions and consequently cardiac output. Hence, Passive Leg Raising (PLR), the intake of small amounts of fluid, the variation of pulse pressure, variations in the diameter of large veins have all been widely used for evaluating fluid responsiveness (FR), within this context. Objective: The underlying objective behind this study was to test, if the non-invasive evaluation with transthoracic echocardiography, the Subaortic velocity time integral (VTI), the Distensibility Index of the Inferior Vena Cava (dIVC), the mitral velocity time integral (MTI), the (CVP) and the change in pulse pressure (ΔPP) after (PLR) and fluid infusion (500ml of saline solution) are able to predict the responsiveness of fluid therapy. Methods: Thirty one hemodynamically unstable patients, under mechanical ventilation (MV) were included in the study. Evaluations were made of VTI, MTI, DIVC), ΔPP and CVP before any intervention, after PLR and after infusion of 500ml saline solution. The variations of the parameters were calculated for all patients. Results: After PLR and infusion of saline solution, the VTI increased by 10% or more in 14 (45%) and 18 (58%) patients, respectively, defined as fluid responders. The PLR predicted a response capacity to fluids with a sensibility of 77,7%, specificity of 100%, a positive predictive value of 100% and a false positive probability of 0%. The CVP, dIVC, ΔPP, PAM and the medical evaluation were not capable of providing an adequate FR evaluation. Conclusion: In hemodynamically unstable patients under MV, PLR were capable of precisely predicting the capacity of FR. / Dissertação (Mestrado)
199

Avaliação do estresse oxidativo e modulação autonômica cardiovascular pós-irradiação de laser de baixa intensidade em ratos espontaneamente hipertensos: estudo experimental

Tomimura, Suely 17 December 2013 (has links)
Submitted by Nadir Basilio (nadirsb@uninove.br) on 2015-07-20T18:01:54Z No. of bitstreams: 1 Suely Tomimura.pdf: 1781054 bytes, checksum: acaac7dbd088721fbe65530e5cd96c5f (MD5) / Made available in DSpace on 2015-07-20T18:01:54Z (GMT). No. of bitstreams: 1 Suely Tomimura.pdf: 1781054 bytes, checksum: acaac7dbd088721fbe65530e5cd96c5f (MD5) Previous issue date: 2013-12-17 / Due to the increasing numbers of Systemic Arterial Hypertension (HBP) patients in population and its senescence, steadily increased from 600 million in 1980 to 1.2 billion in 2008. The World Health Organization (WHO) in 2009 attributed to high blood pressure (BP) was the death cause for 9.5 million people worldwide. Currently, the hypertension has become a serious public health problem. This entity is an important risk factor for congestive heart failure, cerebrovascular disease, acute myocardial infarction, nephropathy, retinopathy and peripheral vascular insufficiency. Studies have suggested that laser photobiomulation, employing a low power, acts into the inflammatory and proliferative phases of tissue repair, by modulating the inflammatory mediators synthesis as same as the Reactive Oxygen Species (ROS). According scientific publications indicate that the inflammation component is closely related to systemic arterial hypertension as well as possibly to the oxidative stress, both participates in the Hypertension genesis. The aim of this study was to verify the long-term effects of Low Level Laser Therapy (LLLT) application in Spontaneously Hypertensive Rats-SHR (Spontaneously Hypertensive Rats) through on cardiovascular autonomic modulation and oxidative stress in the blood. The experiment consisted in 3 phases: Phase I – LLLT irradiation on SHR: The experiment's phase I consisted of animal’s irradiation, when the laser group received three times LLLT applications weekly for a 7 weeks total; the sham group received three times per week of LLLT simulation for 7 weeks and a total of 21 applications. Prospective, randomized, controlled study, with 16 SHR approximately 2 months age, randomly divided into 2 groups : Sham (n = 8) and Laser (n = 8). The animals were irradiated in a prompt, onto the tail’s dorsal area, using a Diode Laser (MMOptics, São Carlos, SP, Brazil) with a wavelength (λ) of 780 ± 2 (nm), output power at 40 mW, with a 0.04 cm2 beam area, dose of 30 J/cm2 power density of 1W/cm2 and irradiation time of 90 s. In Phase II - Hemodynamic and autonomic cardiovascular evaluation: for a period of 7 weeks, consisted in the cannulation procedure, collecting and analysis. The animals were cannulated, evaluated hemodynamically and analyzed the cardiovascular autonomic modulation. Phase III - Oxidative stress analysis, were analyzed: a) protein damage; b) cell membrane damage; c) antioxidant enzyme activity; d) nitrite concentrations. Data from phase II and III were collected and statistically analyzed applying One Way ANOVA test, followed by post hoc Student - Newman Keulls and considering the significance level of p < 0.05, equivalent to an error α 0.05. The results demonstraded hemodynamic parameters of group LLLT treated showed a BP reduction, when compared with the Sham group. In laser group the diastolic arterial pressure (DAP) showed a reduction of -14 mmHg (± 143 * 4 x 157 ± 3 mmHg Sham) and mean arterial pressure (MAP) - 13mmHg (169 ± 4 * x 182 ± 4 mmHg Sham) there were statistically significant difference. Although the value of systolic arterial pressure (SAP) (196 ± 5 x 207 ± 4 mmHg) showed no differences. There was a decreased in resting HR with a statistically significant difference in the laser group compared to Sham (312 ± 14 vs. 361 ± 13 bpm sham). The spectral reviews in the field of time and frequency showed that the Laser group decreased sympathetic activity on the heart and blood vessels while compared to the Sham group. The heart rate variation was analyzed using the DP-PI ( standard deviation of the pulse interval) VAR-PI components (pulse interval variability) and it demonstrated that LLLT was effective in diminishing variation in heart rate (HR) and sympathetic activity in heart, inducing a substantial fall in blood pressure. Lasertherapy presented a rise in spectral low-frequency component in the pulse interval (LF - IP action of the sympathetic at heart), though the sham group showed up exaggeratedly decreasing (6.77 ± 4:35 and 2:31 ± 0:16 ms ² Sham) as a function of saturation variation. Thus, there was a significant reduction in sympathetic activity after LLLT using. A high-frequency band on interval pulse HF-IP (parasympathetic activity) showed no statistically significant differences between the groups and Laser Sham group. The baroreceptor sensitivity, assessed by the alpha index, signalized a significant increase in the Laser (1:07 ± 0:23 vs. 0:45 ± 0:20 ms / mmHg Sham) group, presenting an improvement in the receptors sensitivity. The baroreflex results were associated with other relevant data, the VAR - SAP (49.55 ± 15.94 * vs 70.51 ± 13:55 mmHg² Sham) and SD -SAP (6.94 ± 1.21 * vs 8.68 ± 1.11 mmHg Sham) that proved to be diminished in the laser group, indicating baroreflex improvement sensitivity concomitantly to the positive SAP variation reduction of. There were no significant differences in baseline SAP (196 ± 5 vs. 207 ± 4 mmHg Sham) between the two groups. The results in the oxidative stress and autonomic analysis demonstrated an association between increased NO production (nitrite 0:36 ± 0:03 vs 0:26 ± 0:03 nm / mg Sham) and decreased in the vascular sympathetic (LF - SAP 7.28 ± 1.63 * vs 9.86 ± 0.47 Sham), both leading to a profound vasodilatation then a significant fall in of blood pressure. Lasertherapy shown to alter the plasma parameters such as oxidative nitrite, revealing an NO increased metabolism, as described above and, moreover, accounted for a significant reduction in carbonyl plasma concentration (vs 3.93 ± 0.24, 4.75 ± 0:26 * nm / mg Sham). Our experimental study indicate that LLLT was able to reduce the oxidative stress parameters through diminishing the damage to the proteins. The enzymatic defense was analyzed by the enzyme SOD concentration in blood plasma, denoted that no significant differences (4:42 ± 0:10 4:25 ± 0:06 vs usod / mg) between groups. Thus, low level laser therapy has shown to improve cardiovascular autonomic activity as well as oxidative parameters which resulted in steadily staggeringly reduce the blood pressure of hypertensive animals. / Em razão do aumento populacional e a senescência, o número de indivíduos com Hipertensão Arterial Sistêmica (HAS) cresceu de 600 milhões em 1980 para 1,2 bilhões (OMS 2011). Lim (2012) atribuiu que a pressão arterial (PA) elevada fosse a causa mortis de 9,5 milhões de indivíduos ao redor do mundo. Atualmente, a HAS tornou-se um grave problema de saúde pública. A hipertensão é um importante fator de risco para insuficiência cardíaca congestiva, doenças cerebrovasculares, infarto agudo do miocárdio, nefropatia, insuficiência vascular periférica e retinopatia hipertensiva. Considerando publicações científicas que demonstram que o componente da inflamação e do estresse oxidativo estão intimamente relacionados à gênese da hipertensão arterial sistêmica (HAS), e que o laser com potência baixa tem efeito positivo no estresse oxidativo e apresenta ação antiinflamatória eficaz, desta forma buscamos estudar a resposta da Laserterapia na HAS. Inúmeros estudos vêm sugerindo, ao longo de décadas, que a fotobiomulação pelo laser empregado uma potência baixa, atua durante as fases inflamatórias e proliferativas da reparação tissular, modulando síntese de mediadores inflamatórios e espécies reativas de oxigênio (ROS). O objetivo deste estudo foi analisar os efeitos da aplicação do laser de baixa intensidade em ratos espontaneamente hipertensos SHR (Spontaneously Hypertensive Rats) em longo prazo na modulação autonômica cardiovascular e no estresse oxidativo sangúineo. Estudo prospectivo, randomizado e controlado com 16 ratos SHR, divididos aleatoriamente em 2 grupos: Sham (n=8) e Laser (n=8).O experimento foi dividido em três fases: Fase I – Irradiação dos animais: constituiu-se na irradiação com laser nos animais SHR, onde o grupo Laser recebeu três aplicações semanais de LBI durante sete semanas; já no grupo Sham foram realizados três simulações de aplicação semanais de Laser de Baixa Intensidade (LBI) durante 7 semanas, totalizando 21 aplicações de LBI. Os animais foram irradiados pontualmente, na região dorsal da cauda, utilizando um Laser Diodo (MMOptics, São Carlos, SP, Brasil) com comprimento de onda de λ = 780 ± 2 (nm); potência de 40 mW, área do feixe de 0,04 cm2, densidade de energia de 30 J/cm2, densidade de potência de 1W/cm2, tempo total de irradiação de 90 s de exposição. Fase II – Avaliação hemodinâmica e autonômica cardiovascular: constituiu-se nos procedimento de canulação, registro de dados e coleta de material, teve inicio após sete semanas de irradiação. Os animais canulados foram avalidados de forma hemodinâmica, bem como analisada a modulação autonômica cardiovascular. Fase III – Análises do estresse oxidativo, foram analisadas: a) danos à proteína; b) danos à membrana celular; c) atividade enzimática; d) concentração de nitrito. Os dados da fase II e III foram coletados e analisados estatisticamente através dos testes Anova One Way, seguido de Post Hoc de Student Newman-Keulls, considerando-se o nível de significância p < 0,05, equivalendo a um erro α de 0.05. Os resultados hemodinâmicos do grupo tratado com LLLT denotaram um decréscimo significativo da PA quando comparado com o grupo Sham. A pressão arterial diastólica (PAD) do grupo Laser revelou uma redução de -14 mmHg (143± 4*vs157±3 mmHg Sham) e a pressão arterial média (PAM) -13mmHg (169±4*vs182±4 mmHg Sham), a frequência cardíaca (FC) em repouso (312±14*vs361±13 bpm Sham) revelando uma diferença estatisticamente significante, porém o valor da pressão arterial sistólica(PAS) não mostrou (196±5 x 207±4 mmHg) alterações entre os grupos. As avaliações espectrais no domínio do tempo e da frequencia demostraram que o grupo Laser reduziu a atividade simpática sobre o coração e vasos sanguíneos quando comparados ao grupo Sham. A variação frequência cardíaca foi analisada através dos componentes VAR-IP (variabilidade do intervalo de pulso) e o DP-IP (desvio do intervalo de pulso) que evidenciaram que o LBI foi eficaz no decréscimo variação da FC e da atividade simpática no coração, induzindo assim a queda das pressões arteriais. A laserterapia mostrou um incremento no componente espectral baixa frequência no intervalo de pulso (BF-IP ação do simpático no coração), porém o grupo Sham apresentou-se exacerbadamente diminuído (6.77 ± 4.35 e 2.31±0.16 ms² Sham) em função da saturação da variação desse componente que foi reduzido. Desta forma, houve um importante decréscimo da atividade simpática com o uso do LBI, significando uma importante diminuição dos níveis pressóricos. A banda de alta frequência (AF-IP atividade parassimpática cardíaca) não mostrou diferenças estatísticas significantes entre os grupos Laser e grupo Sham. A sensibilidade dos barorreceptores, avaliada pelo índice alfa, demonstrou um significativo incremento da resposta no grupo Laser (1.07 ± 0.23 vs 0.45 ± 0.20 ms/mmHg Sham), revelando uma melhora na sensibilidade destes receptores. Os resultados dos barorreflexos encontravam-se associados a outro dado relevante, o componente VAR-PAS (49.55 ± 15.94* vs 70.51 ± 13.55 mmHg² Sham) e DP-PAS (6.94 ± 1.21* vs 8.68 ± 1.11 mmHg Sham) que mostrou-se diminuído no grupo Laser, indicando que a melhora da sensibilidade barorreflexa ocorreu, concomitantemente, à redução positiva da variação da PAS. Não houve diferenças estatísticas significantes na PAS basal (196±5 vs 207 ± 4 mmHg Sham) entre os dois grupos. Já os resultados encontrados na análise do estresse oxidativo e autonômica demonstraram uma associação entre o incremento da produção do óxido nitrico (NO) (nitrito 0.36 ± 0.03 vs 0.26 ± 0.03 nm/mg Sham) e redução do simpático vascular (BF-PAS 7.28 ± 1.63* vs 9.86 ± 0.47 Sham), ambos levando a uma vasodilatação com consequente queda dos níveis pressóricos arteriais. A laserterapia mostrou alterar parâmetros oxidativos como as espécies reativas de nitrogênio (RNS reactive nitrogen species), o nitrito plasmático, revelando um aumento do metabolismo do NO, como já descrito anteriormente e denotou uma diminuição significativa da concentração de carbonilas plasmáticas (3.93 ± 0.24 * vs 4.75 ± 0.26 nm/mg Sham). A defesa enzimática foi analisada através da concentração da enzima SOD no plasma sanguíneo, que não apontou diferenças significativas (4.42 ± 0.10 vs 4.25 ± 0.06 usod/mg) entre os grupos. Evidenciamos que o LBI foi capaz de reduzir este parâmetro oxidativo, reduzindo os danos às proteínas decorrente do estresse. Desta forma, concluímos que a laserterapia demonstrou resposta positiva ao melhorar a atividade autonômica cardiovascular e parâmetros oxidativos que resultaram na redução dos níveis pressóricos dos animais hipertensos.
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Evoluční algoritmy pro ultrazvukovou perfúzní analýzu / Evolution algorithms for ultrasound perfusion analysis

Hemzalová, Zuzana January 2021 (has links)
This thesis deals with the principles of ultrasonic perfusion analysis and methods for determining perfusion parameters. It examines Evolutionary algorithms and their ability to optimize the approximation of dilution curves from ultrasond tissue scannig. It compares the optimization performance of three evolutionary algorithms. Continuous genetic algorithm GA, algorithm SOMA and PSO. Methods are evaluated on simulated and clinical data.

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