Thiol-mediated regulation of ICAM-1 expression in endotoxin-induced acute lung injury

The intracellular redox state regulates several aspects of cell function, suggesting that strategies directed toward altering the cellular redox state may modulate cell activation in inflammatory states. As the most abundant intracellular thiol, glutathione plays a critical role as an intracellular redox buffer. Using diethylmaleate (DEM) as a glutathione-depleting agent, we evaluated the effects of GSH depletion in a rodent model of polymorphonuclear neutrophil (PMN)-dependent acute lung injury. Rats received 500 microg of LPS by intratracheal challenge, inducing a 5.5-fold increase in lung permeability and sixfold increase in lung PMN content. Pretreatment with DEM prevented the LPS-induced increase in lung PMN influx and lung permeability. Northern analysis and immunohistochemical studies suggest that this effect may be mediated by preventing up-regulation of lung ICAM-1 mRNA and protein expression. This effect is specific to ICAM-1, because lung cytokine-induced neutrophil chemoattractant and TNF-alpha mRNA levels are unaffected. This finding is not unique to the lung, because a similar effect on PMN influx was recapitulated in a rodent model of chemical peritonitis. Further, in vitro studies demonstrated that pretreatment of HUVEC monolayers with DEM prevented both ICAM-1 up-regulation and PMN transendothelial migration. These data indicate the presence of a thiol-sensitive mechanism for modulating ICAM-1 gene expression and suggest a potential novel therapeutic strategy for diseases characterized by PMN-mediated tissue injury.     

Switching times variation of MOSFET devices with temperature and high-field stress

Switching times of power MOSFET devices are investigated as function of temperature and high-field stress. Measurements show that important variations are obtained on the devices turn-on time. The threshold voltage is decreasing with temperature and varies with stress, especially at low temperatures. The oxide leakage current is found to be having safe values even at high temperatures, stressing the devices does not increase the leakage current to unsafe values except for very high temperatures.     

The filter design from data (FD2) problem: parametric‐statistical approach

A large body of literature exists on the filter design problem, assuming that the system to be filtered is known. However, in most practical situations, the system is not known, but a set of measured data is available. In such situations, a two‐step procedure is typically adopted: a model is identified from this data set, and a filter is designed based on the identified model. In this paper, we consider an alternative approach, which uses the available data not for the identification of a model, but for the direct design of the filter. Such a direct design is investigated within a parametric‐statistical framework for both the cases of linear time‐invariant and nonlinear systems. The noise is assumed to be stochastic, and optimality refers to minimizing the estimation error variance. It is shown that the direct design has superior features with respect to the two‐step design, especially in the presence of modeling errors. Another relevant advantage of the direct design over the two‐step procedure is that minimum variance (Kalman) filters for nonlinear systems are, in general, difficult to derive and/or to implement. On the contrary, the direct approach allows for a very efficient filter design. To demonstrate the effectiveness of the proposed direct design, two examples are presented: the first is related to estimation of the Lorentz chaotic attractor; the second, involving real data, is related to estimation of vehicle yaw rate. Copyright © 2011 John Wiley & Sons, Ltd.     

Effect of multiple unconfined compression on cellular dense collagen scaffolds for bone tissue engineering

Plastic compression of hydrated collagen gels rapidly produces biomimetic scaffolds of improved mechanical properties. These scaffolds can potentially be utilised as cell seeded systems for bone tissue engineering. This work investigated the influence of multiple unconfined compression on the biocompatibility and mechanical properties of such systems. Single and double compressed dense collagen matrices were produced and characterised for protein dry weight, morphology and mechanical strength. Compression related maintenance of the seeded HOS TE85 cell line viability in relation to the extent of compression was evaluated up to 10 days in culture using the TUNEL assay. Fluorescence Live/Dead assay was conducted to examine overall cell survival and morphology. Cell induced structural changes in the dense collagenous scaffolds were assessed by routine histology. The mechanical properties of the cellular scaffolds were also evaluated as a function of time in culture. It is clear that a single plastic compression step produced dense collagenous scaffolds capable of maintaining considerable cell viability and function as signs of matrix remodeling, and maintenance of mechanical properties were evident. Such scaffolds should therefore be further developed as systems for bone tissue regeneration.     

Sensory Thresholds of Selected Phenolic Constituents from Thyme and their Antioxidant Potential in Sunflower Oil

The odor detection thresholds of carvacrol (5-isopropyl-2-methyl-phenol), thymol (2-isopropyl-5-methyl-phenol) and p-cymene 2,3-diol (2,3-dihydroxy-4-isopropyl-1-methyl-benzene) in sunflower oil, determined by the three-alternative, forced-choice procedure, were 30.97, 124 and 794.33 mg kg⁻¹, respectively. Sunflower oil containing 13, 70, or 335 mg kg⁻¹ of carvacrol, thymol or p-cymene 2,3-diol, respectively, was judged to be similar (P < 0.01) in taste and odor to its antioxidant-free counterpart. The rate constant of sunflower oil oxidation, measured from the increase in peroxide value during storage at 25 °C, was 9.2 × 10⁻⁹ mol kg⁻¹ s⁻¹ while the rate constants were 9.3 × 10⁻⁹, 9.8 × 10⁻⁹, and 4.3 × 10⁻⁹ mol kg⁻¹ s⁻¹ in the presence of 13 mg kg⁻¹ carvacrol, 70 mg kg⁻¹ thymol, and 335 mg kg⁻¹ p-cymene 2,3-diol, respectively. At a level of 335 mg kg⁻¹, p-cymene 2,3-diol did not impart flavor taints and effected a 46.7% reduction in the rate of oxidation of sunflower oil. These findings indicate that the diphenolic p-cymene 2,3-diol could potentially replace synthetic antioxidants and is a valuable addition to the antioxidants used by the food industry in its quest to meet consumer demands for synthetic-additives-free and ‘natural’ foods.     

Expansion of isolated electrical systems in the Amazon: An approach using fuzzy multi-objective mathematical programming

This paper examines some problems encountered in the expansion of isolated electrical systems (IES) in the Amazon region, more precisely, the thermoelectric systems used in that region. Supposing a certain degree of uncertainty in energy consumption, we evaluate the expansion of thermoelectric power from firewood and diesel fuel, together with variations for costs, CO₂ emissions, and number of direct jobs (NDJ) generated with the use of these technologies. The analysis is accomplished by using fuzzy multi-objective mathematical programming, and interpreting each objective function both by itself and in combination with the others, through a fuzzy multi-objective parametrization. The scenarios are defined by the energy consumption percentage increase, limited to be below some admissible maximum value, while still considering variations in the installed power. The costs, CO₂ emission, and the NDJ generated are analyzed and compared with the largest values obtained with the model of crisp mathematical programming, used for the original configuration. Finally, in Section 4, we present the results and respective analyses for the finished simulation.     

In utero management of hydrops fetalis caused by critical aortic stenosis

Hydrops fetalis is rarely associated with congestive heart failure caused by obstructive left-sided heart lesions. There are rare cases of live born neonates with critical congenital valvar aortic stenosis and hydrops reported in the literature, all with fatal outcomes. This report describes, to the best of our knowledge, the first two newborns who were diagnosed prenatally to have hydrops fetalis caused by critical valvar aortic stenosis, who were treated prenatally with digoxin and who postnatally had successful percutaneous balloon aortic valvuloplasty. Both patients had not only left but right ventricular dysfunction. We speculate that right ventricular dysfunction was a contributing factor in the development of hydrops in these patients and in utero medical therapy with digoxin is associated with resolution of the hydrops before delivery.