Neutrophil apoptosis, phagocytosis and oxidative metabolism in septic patients

Sepse denota a continuidade de um processo de injuria tecidual onde a disfuncao organica multipla representa sua expressao mais grave. Trata-se de uma condicao patologica associada a altas taxas de mortalidade. Diferentes linhagens celulares estao relacionadas a sua fisiopatogenia. Neutrofilos, por exemplo, sao as primeiras celulas da linha de defesa a migrarem para os sitios de inflamacao e/ou infeccao. Suas funcoes primarias incluem fagocitose de bacterias, elaboracao de enzimas oxidativas e nao oxidativas de degradacao, e formacao de fatores quimiotaticos para recrutar outras celulas inflamatorias. O objetivo desse estudo foi avaliar os efeitos da sepse grave e do choque septico na apoptose e na funcao de neutrofilos, sendo esta analisada pela capacidade fagocitica e pelo metabolismo oxidativo. Para tanto, foram incluidos 10 pacientes com quadro clinico e laboratorial de sepse grave ou choque septico com menos de 48 horas de evolucao, classificados de acordo com as definicoes do consenso de 1992 do American College of Chest Physicians / Society of Critical Care Medicine Consensus Conference, internados em Unidade de Terapia Intensiva do Hospital São Paulo, e 10 individuos sadios, maiores de 18 anos, que nao se encontravam em uso de nenhum medicamento, considerados controles. De cada paciente ou voluntario sadio foram coletadas amostras de 10 ml de sangue arterial ou venoso periferico em tubos estereis com 100 U de heparina para realizacao dos ensaios de apoptose, fagocitose e metabolismo oxidativo, utilizando citometria de fluxo...(au)BV UNIFESP: Teses e dissertaçõe

Nonlinear Model Predictive Control for Integrated Energy-Efficient Torque-Vectoring and Anti-Roll Moment Distribution

This study applies nonlinear model predictive control (NMPC) to the torque-vectoring (TV) and front-to-total anti-roll moment distribution control of a four-wheel-drive electric vehicle with in-wheel-motors, a brake-by-wire system, and active suspension actuators. The NMPC cost function formulation is based on energy efficiency criteria, and strives to minimize the power losses caused by the longitudinal and lateral tire slips, friction brakes, and electric powertrains, while enhancing the vehicle cornering response in steady-state and transient conditions. The controller is assessed through simulations using an experimentally validated high-fidelity vehicle model, along ramp steer and multiple step steer maneuvers, including and excluding the direct yaw moment and active anti-roll moment distribution actuations. The results show: 1) the substantial enhancement of energy saving and vehicle stabilization performance brought by the integration of the active suspension contribution and TV; 2) the significance of the power loss terms of the NMPC formulation on the results; and 3) the effectiveness of the NMPC with respect to the benchmarking feedback and rule based controllers

Matrix metalloproteinases and soluble Fas/FasL system as novel regulators of apoptosis in children and young adults on chronic dialysis

The system of membrane receptor Fas and its ligand FasL compose one of the main pathways triggering apoptosis. However, the role of their soluble forms has not been clarified yet. Although sFasL can be converted from the membrane-bound form by matrix metalloproteinases (MMPs), there are no data on relations between sFas/sFasL, MMPs and their tissue inhibitors (TIMPs) in patients on chronic dialysis—neither children nor adults. The aim of our study was to evaluate serum concentrations of sFas, sFasL, and their potential regulators (MMP-2, MMP-7, MMP-9, TIMP-1, TIMP-2), in children and young adults chronically dialyzed. Twenty-two children on automated peritoneal dialysis (APD), 19 patients on hemodialysis (HD) and 30 controls were examined. Serum concentrations of sFas, sFasL, MMPs and TIMPs were assessed by ELISA. Median values of sFas, sFasL, sFas/sFasL ratio, MMP-2, MMP-7, MMP-9, TIMP-1 and TIMP-2 were significantly elevated in all dialyzed patients vs. controls, the highest values being observed in subjects on HD. A single HD session caused the decrease in values of all parameters to the levels below those seen in children on APD. Regression analysis revealed that MMP-7 and TIMP-1 were the best predictors of sFas and sFasL concentrations. Children and young adults on chronic dialysis are prone to sFas/sFasL system dysfunction, more pronounced in patients on hemodialysis. The correlations between sFas/sFasL and examined enzymes suggest that MMPs and TIMPs take part in the regulation of cell death in the pediatric population on chronic dialysis, triggering both anti- (sFas) and pro-apoptotic (sFasL) mechanisms

Characterization of relapsing-remitting multiple sclerosis patients using support vector machine classifications of functional and diffusion MRI data.

Multiple Sclerosis patients' clinical symptoms do not correlate strongly with structural assessment done with traditional magnetic resonance images. However, its diagnosis and evaluation of the disease's progression are based on a combination of this imaging analysis complemented with clinical examination. Therefore, other biomarkers are necessary to better understand the disease. In this paper, we capitalize on machine learning techniques to classify relapsing-remitting multiple sclerosis patients and healthy volunteers based on machine learning techniques, and to identify relevant brain areas and connectivity measures for characterizing patients. To this end, we acquired magnetic resonance imaging data from relapsing-remitting multiple sclerosis patients and healthy subjects. Fractional anisotropy maps, structural and functional connectivity were extracted from the scans. Each of them were used as separate input features to construct support vector machine classifiers. A fourth input feature was created by combining structural and functional connectivity. Patients were divided in two groups according to their degree of disability and, together with the control group, three group pairs were formed for comparison. Twelve separate classifiers were built from the combination of these four input features and three group pairs. The classifiers were able to distinguish between patients and healthy subjects, reaching accuracy levels as high as 89% ± 2%. In contrast, the performance was noticeably lower when comparing the two groups of patients with different levels of disability, reaching levels below 63% ± 5%. The brain regions that contributed the most to the classification were the right occipital, left frontal orbital, medial frontal cortices and lingual gyrus. The developed classifiers based on MRI data were able to distinguish multiple sclerosis patients and healthy subjects reliably. Moreover, the resulting classification models identified brain regions, and functional and structural connections relevant for better understanding of the disease

Absolute Two-tracked Optical Rotary Encoders Based on Vernier Method

Driving synchronous machines requires early and accurate knowledge of the absolute position of the rotor; current solutions based on resolvers, sin-cos or absolute encoders are complex, bulky and costly. Hence, in this work two variants of absolute rotary encoder based on Vernier method are analyzed. One, already discussed in the literature, displays the Vernier scale across the whole circumference (full-Vernier), the other shows half Vernier traces over the entire perimeter (half-Vernier), which is an original feature. Both implementations are characterized by only two tracks and as many sensors: the proposed conditioning algorithms provide the absolute angular position as a function of the time delays between the wave edges generated by the two traces, thus being of easy implementation on low-cost MCUs. The Vernier encoders are also compared with state-of-the-art absolute and relative solutions, i.e. incremental, binary and Gray-code encoders. Experimental tests are carried out to assess the accuracy of the proposed sensors. The investigation shows that (i) the full-Vernier cannot provide, in practice, a reliable estimate of the direction of rotation and of the actual angular sector without resorting to a third sensor; (ii) the half-Vernier produces a trusty measurement of the absolute angle and velocity and (iii) can give a reliable position result with less than 30° shaft turn, but (iv) it can suffer from marginal performance degradation at low velocities in conjunction with high accelerations. Compared to the Gray encoder, the half-Vernier provides a simpler and more compact hardware for a given resolution, similar to that of an incremental encoder, at the expense of a small accuracy reduction at low speed

Soft-Body Modeling: A Scalable and Efficient Formulation for Control-Oriented Simulation of Electric Vehicles

Electric vehicle (EV) modeling based on soft-body formulation is proposed as an alternative method suitable for the simulation of EVs and for the study of dynamic control strategies. This investigation strives to assess how this different formulation can be exploited to overcome the limitations of the traditional modeling methods. At this purpose, a soft-body tire model is created and tuned accurately; hence, the vehicle system founded upon the soft-body formulation is compared with two analytical models and with the result of an established opensource multibody simulator