976 resultados para Physical Testing
Resumo:
OBJECTIVE: To assess the influence of skeletal muscle mass on ventilatory and hemodynamic variables during exercise in patients with chronic heart failure (CHF). METHODS: Twenty-five male patients underwent maximum cardiopulmonary exercise testing on a treadmill with a ramp protocol and measurement of the skeletal muscle mass of their thighs by using magnetic resonance imaging. The clinically stable, noncachectic patients were assessed and compared with 14 healthy individuals (S) paired by age and body mass index, who underwent the same examinations. RESULTS: Similar values of skeletal muscle mass were found in both groups (CHF group: 3863 ± 874 g; S group: 3743 ± 540 g; p = 0.32). Significant correlations of oxygen consumption in the anaerobic threshold (CHF: r = 0.39; P= 0.02 and S: r = 0.14; P = 0.31) and of oxygen pulse also in the anaerobic threshold (CHF: r = 0.49; P = 0.01 and S: r =0.12; P = 0.36) were found only in the group of patients with chronic heart failure. CONCLUSION: The results obtained indicate that skeletal muscle mass may influence the capacity of patients with CHF to withstand submaximal effort, due to limitations in their physical condition, even maintaining a value similar to that of healthy individuals. This suggests qualitative changes in the musculature.
Resumo:
El objetivo del presente proyecto es estudiar los procesos físicos y químicos del radical OH con compuestos orgánicos volátiles (COVs), con los cuales sea factible la formación de agregados de van der Waals (vdW) responsables de la curvatura en los gráficos de Arrhenius, empleando técnicas modernas, complementarias entre si y novedosas en el país. El problema será abordado desde tres perspectivas complementarias: 1) estudios cinéticos, 2) estudios mecanísticos y de distribución de productos y 3) estudios de la dinámica de los procesos físicos y químicos. La finalidad es alcanzar una mejor comprensión de los mecanismos que intervienen en el comportamiento químico de especies presentes en la atmósfera y obtener datos cinéticos de alta calidad que puedan alimentar modelos computacionales capaces de describir la composición de la atmósfera, presente y futura. Los objetivos son estudiar: 1) mediante fotólisis láser pulsada con detección por fluorescencia inducida por láser (PLP-LIF), en reactores de flujo, la cinética de reacción del radical OH(v”=0) con COVs que presentan gráficos de Arrhenius curvos con energías de activación negativas, tales como alcoholes insaturados, alquenos halogenados, éteres halogenados, ésteres alifáticos; 2) en una cámara de simulación de condiciones atmosféricas de gran volumen (4500 L), la identidad y el rendimiento de productos de las reacciones mencionadas, a fines de evaluar su impacto atmosférico y dilucidar los mecanismos de reacción; 3) mediante haces moleculares y espectroscopía láser, la estructura y reactividad de complejos de vdW entre alcoholes insaturados o aromáticos (cresoles) y el radical OH, como modelo de los aductos propuestos como responsables de la desviación al comportamiento de Arrhenius de las reacciones mencionadas; 4) mediante PLP-LIF y expansiones supersónicas, las constantes específicas estado a estado (ksts) de relajación/reacción del radical OH(v”=1-4) vibracionalmente excitado con los COVs mencionados. Los resultados experimentales obtenidos serán contrastados con cálculos ab-initio de estructura electrónica, los cuales apoyarán las interpretaciones, permitirán proponer estructuras de estados de transición y aductos colisionales, como así también calcular las frecuencias de vibración de los complejos de vdW para su posterior asignación en los espectros LIF y REMPI. Asimismo, los mecanismos de reacción propuestos y los parámetros cinéticos medidos experimentalmente serán comparados con aquellos obtenidos por cálculos teóricos. The aim of this project is to study the physical and chemical processes of OH radicals with volatile organic compounds (VOCs) with which the formation of van der Waals (vdW) clusters, responsible for the observed curvature in the Arrhenius plots, might be feasible. The problem will be addressed as follow : 1) kinetic studies; 2) products distribution and mechanistic studies and 3) dynamical studies of the physical and chemical processes. The purpose is to obtain a better understanding of the mechanisms that govern the chemical behavior of species present in the atmosphere and to obtain high quality kinetic data to be used as input to computational models. We will study: 1) the reaction kinetics of OH (v”=0) radicals with VOCs such as unsaturated alcohols, halogenated alkenes, halogenated ethers, aliphatic esters, which show curved Arrhenius plots and negative activation energies, by PLP-LIF, in flow systems; 2) in a large volume (4500 L) atmospheric simulation chamber, reaction products yields in order to evaluate their atmospheric impact and reaction mechanisms; 3) using molecular beams and laser spectroscopy, the structure and reactivity of the vdW complexes formed between the unsaturated or aromatic alcohols and the OH radicals as a model of the adducts proposed as responsible for the non-Arrhenius behavior; 4) the specific state-to-state relaxation/reaction rate constants (ksts) of the vibrationally excited OH (v”=1-4) radical with the VOCs by PLP-LIF and supersonic expansions. Ab-initio calculations will be carried out to support the interpretation of the experimental results, to obtain the transition state and collisional adducts structures, as well as to calculate the vibrational frequencies of the vdW complexes to assign to the LIF and REMPI spectra. Also, the proposed reaction mechanisms and the experimentally measured kinetic parameters will be compared with those obtained from theoretical calculations.
Resumo:
Historically, shifts to reduced and no-tillage management for production of crops were fostered by needs to decrease soil erosion and loss of organic matter, reduce fuel and labour costs and conserve soil water, as compared with conventional fallow tillage management. Recent interest in maintaining soil quality has been stimulated by a renewed awareness of the importance of soil condition to both the sustainability of agricultural production systems and environmental quality (Doran and Parkin, 1996). The aim of this project was to determine the impact on the physical, chemical and microbiological status of the soil of conventional and reduced tillage. It has been suggested that the reduced soil disturbance associated with the tine cultivator improves soil structure, increases nutrient content in the top 10cm of soil, increases microbial activity and improves physical characteristics. From this study it was determined that the environmental benefits linked to reduced tillage in literature, did not develop in the first two years of this programmes implementation. The results of this study determined that soil nutrients did not increase in concentration in the top 10 cm of soil under reduced cultivation. The only exception was exchangeable potassium. As potassium is not a mobile nutrient its movement is dependent on soil disturbance, therefore under reduced cultivation its concentration was allowed to accumulate in the upper horizon of the soil profile. Microbial activity was greater in the conventionally tilled treatments, as determined by total aerobic bacterial numbers. This could be due to the increased rates of soil aeration in this treatment. Numbers of aerobic bacteria were greater in the conventional tillage treatments at both incubation temperatures of 22 and 32° C. The physical characteristics of the soil determined, indicate that below the depth of soil cultivation, cone penetration resistance increases. Therefore the reduced cultivation treatments would be more prone to soil compaction, higher in the soil profile.
Resumo:
As digital imaging processing techniques become increasingly used in a broad range of consumer applications, the critical need to evaluate algorithm performance has become recognised by developers as an area of vital importance. With digital image processing algorithms now playing a greater role in security and protection applications, it is of crucial importance that we are able to empirically study their performance. Apart from the field of biometrics little emphasis has been put on algorithm performance evaluation until now and where evaluation has taken place, it has been carried out in a somewhat cumbersome and unsystematic fashion, without any standardised approach. This paper presents a comprehensive testing methodology and framework aimed towards automating the evaluation of image processing algorithms. Ultimately, the test framework aims to shorten the algorithm development life cycle by helping to identify algorithm performance problems quickly and more efficiently.
Resumo:
v.4(1935)
Resumo:
The research described in this thesis was developed as part o f the Information Management for Green Design (IMA GREE) Project. The 1MAGREE Project was founded by Enterprise Ireland under a Strategic Research Grant Scheme as a partnership project between Galway Mayo Institute o f Technology and C1MRU University College Galway. The project aimed to develop a CAD integrated software tool to support environmental information management for design, particularly for the electronics-manufacturing sector in Ireland.
Resumo:
This is a study of a state of the art implementation of a new computer integrated testing (CIT) facility within a company that designs and manufactures transport refrigeration systems. The aim was to use state of the art hardware, software and planning procedures in the design and implementation of three CIT systems. Typical CIT system components include data acquisition (DAQ) equipment, application and analysis software, communication devices, computer-based instrumentation and computer technology. It is shown that the introduction of computer technology into the area of testing can have a major effect on such issues as efficiency, flexibility, data accuracy, test quality, data integrity and much more. Findings reaffirm how the overall area of computer integration continues to benefit any organisation, but with more recent advances in computer technology, communication methods and software capabilities, less expensive more sophisticated test solutions are now possible. This allows more organisations to benefit from the many advantages associated with CIT. Examples of computer integration test set-ups and the benefits associated with computer integration have been discussed.
Resumo:
v. 1
Resumo:
Background: The equations predicting maximal oxygen uptake (VO2max or peak) presently in use in cardiopulmonary exercise testing (CPET) softwares in Brazil have not been adequately validated. These equations are very important for the diagnostic capacity of this method. Objective: Build and validate a Brazilian Equation (BE) for prediction of VO2peak in comparison to the equation cited by Jones (JE) and the Wasserman algorithm (WA). Methods: Treadmill evaluation was performed on 3119 individuals with CPET (breath by breath). The construction group (CG) of the equation consisted of 2495 healthy participants. The other 624 individuals were allocated to the external validation group (EVG). At the BE (derived from a multivariate regression model), age, gender, body mass index (BMI) and physical activity level were considered. The same equation was also tested in the EVG. Dispersion graphs and Bland-Altman analyses were built. Results: In the CG, the mean age was 42.6 years, 51.5% were male, the average BMI was 27.2, and the physical activity distribution level was: 51.3% sedentary, 44.4% active and 4.3% athletes. An optimal correlation between the BE and the CPET measured VO2peak was observed (0.807). On the other hand, difference came up between the average VO2peak expected by the JE and WA and the CPET measured VO2peak, as well as the one gotten from the BE (p = 0.001). Conclusion: BE presents VO2peak values close to those directly measured by CPET, while Jones and Wasserman differ significantly from the real VO2peak.
Resumo:
Background: Studies have demonstrated the diagnostic accuracy and prognostic value of physical stress echocardiography in coronary artery disease. However, the prediction of mortality and major cardiac events in patients with exercise test positive for myocardial ischemia is limited. Objective: To evaluate the effectiveness of physical stress echocardiography in the prediction of mortality and major cardiac events in patients with exercise test positive for myocardial ischemia. Methods: This is a retrospective cohort in which 866 consecutive patients with exercise test positive for myocardial ischemia, and who underwent physical stress echocardiography were studied. Patients were divided into two groups: with physical stress echocardiography negative (G1) or positive (G2) for myocardial ischemia. The endpoints analyzed were all-cause mortality and major cardiac events, defined as cardiac death and non-fatal acute myocardial infarction. Results: G2 comprised 205 patients (23.7%). During the mean 85.6 ± 15.0-month follow-up, there were 26 deaths, of which six were cardiac deaths, and 25 non-fatal myocardial infarction cases. The independent predictors of mortality were: age, diabetes mellitus, and positive physical stress echocardiography (hazard ratio: 2.69; 95% confidence interval: 1.20 - 6.01; p = 0.016). The independent predictors of major cardiac events were: age, previous coronary artery disease, positive physical stress echocardiography (hazard ratio: 2.75; 95% confidence interval: 1.15 - 6.53; p = 0.022) and absence of a 10% increase in ejection fraction. All-cause mortality and the incidence of major cardiac events were significantly higher in G2 (p < 0. 001 and p = 0.001, respectively). Conclusion: Physical stress echocardiography provides additional prognostic information in patients with exercise test positive for myocardial ischemia.
Resumo:
Statin treatment in association with physical exercise practice can substantially reduce cardiovascular mortality risk of dyslipidemic individuals, but this practice is associated with myopathic event exacerbation. This study aimed to present the most recent results of specific literature about the effects of statins and its association with physical exercise on skeletal musculature. Thus, a literature review was performed using PubMed and SciELO databases, through the combination of the keywords “statin” AND “exercise” AND “muscle”, restricting the selection to original studies published between January 1990 and November 2013. Sixteen studies evaluating the effects of statins in association with acute or chronic exercises on skeletal muscle were analyzed. Study results indicate that athletes using statins can experience deleterious effects on skeletal muscle, as the exacerbation of skeletal muscle injuries are more frequent with intense training or acute eccentric and strenuous exercises. Moderate physical training, in turn, when associated to statins does not increase creatine kinase levels or pain reports, but improves muscle and metabolic functions as a consequence of training. Therefore, it is suggested that dyslipidemic patients undergoing statin treatment should be exposed to moderate aerobic training in combination to resistance exercises three times a week, and the provision of physical training prior to drug administration is desirable, whenever possible.
Resumo:
Background: No studies have described and evaluated the association between hemodynamics, physical limitations and quality of life in patients with pulmonary hypertension (PH) without concomitant cardiovascular or respiratory disease. Objective: To describe the hemodynamic profile, quality of life and physical capacity of patients with PH from groups I and IV and to study the association between these outcomes. Methods: Cross-sectional study of patients with PH from clinical groups I and IV and functional classes II and III undergoing the following assessments: hemodynamics, exercise tolerance and quality of life. Results: This study assessed 20 patients with a mean age of 46.8 ± 14.3 years. They had pulmonary capillary wedge pressure of 10.5 ± 3.7 mm Hg, 6-minute walk distance test (6MWDT) of 463 ± 78 m, oxygen consumption at peak exercise of 12.9 ± 4.3 mLO2.kg-1.min-1 and scores of quality of life domains < 60%. There were associations between cardiac index (CI) and ventilatory equivalent for CO2 (r=-0.59, p <0.01), IC and ventilatory equivalent for oxygen (r=-0.49, p<0.05), right atrial pressure (RAP) and 'general health perception' domain (r=-0.61, p<0.01), RAP and 6MWTD (r=-0.49, p<0.05), pulmonary vascular resistance (PVR) and 'physical functioning' domain (r=-0.56, p<0.01), PVR and 6MWTD (r=-0.49, p<0.05) and PVR index and physical capacity (r=-0.51, p<0.01). Conclusion: Patients with PH from groups I and IV and functional classes II and III exhibit a reduction in physical capacity and in the physical and mental components of quality of life. The hemodynamic variables CI, diastolic pulmonary arterial pressure, RAP, PVR and PVR index are associated with exercise tolerance and quality of life domains.