Thyroid Hormones and Antioxidant Systems: Focus on Oxidative Stress in Cardiovascular and Pulmonary Diseases

In previous works we demonstrated an inverse correlation between plasma Coenzyme Q₁₀ (CoQ₁₀) and thyroid hormones; in fact, CoQ₁₀ levels in hyperthyroid patients were found among the lowest detected in human diseases. On the contrary, CoQ₁₀ is elevated in hypothyroid subjects, also in subclinical conditions, suggesting the usefulness of this index in assessing metabolic status in thyroid disorders. A Low-T3 syndrome is a condition observed in several chronic diseases: it is considered an adaptation mechanism, where there is a reduction in pro-hormone T4 conversion. Low T3-Syndrome is not usually considered to be corrected with replacement therapy. We review the role of thyroid hormones in regulation of antioxidant systems, also presenting data on total antioxidant capacity and Coenzyme Q₁₀. Published studies suggest that oxidative stress could be involved in the clinical course of different heart diseases; our data could support the rationale of replacement therapy in low-T3 conditions.     

Evaluation of eye,head and trunk coordination during target tracking tasks

This study tested the feasibility of a method to synchronise and to evaluate eye, head and trunk movement patterns during target tracking tasks performed by 10 subjects. A projected central target was randomly repositioned at 40° and 70° of rotation to the left and right. Subjects were instructed to change gaze as quickly as possible. Head and trunk motion was measured using a motion analysis system, and eye movement was measured using an eye-tracker; all data were synchronised. For healthy subjects, the eye moved faster than the head, there was no trunk movement and the head moved more than the eye to reach further displaced targets. The method tested was feasible, and it could be used to evaluate eye, head and trunk movement patterns of subjects with injuries such as whiplash and concussions.

Practitioner Summary: Studies of eye, head and trunk movements using synchronised methods are needed. We tested the feasibility of a method to synchronise and evaluate eye, head and trunk movement patterns. The method tested was feasible, and it could be used to evaluate movement patterns of subjects with injuries such as whiplash.     

CYCLIC LOADING BEHAVIOUR OF SODA-LIME SILICATE GLASS USING INDENTATION CRACKS

Abstract— Cyclic loading behaviour of soda-lime silicate glass was studied using Vickers indentation flaws. Glass bars were indented in air using a load of 9.8 N. Some samples were annealed in order to remove the indentation residual stress field. Both as-indented and annealed specimens were subjected to static and cyclic bending tests in a water environment using a four-point bending configuration. The influence of maximum stress on lifetime was considered. Crack propagation was examined by fractography and fracture patterns were similar to those observed in static fatigue. Characteristic fracture markers were seen on samples subjected to cyclic load. Experimental results were compared with theoretical predictions which were obtained on the basis of typical sub-critical crack growth behaviour. Precise determination of crack shape and residual stress factors were shown to play an important role in lifetime predictions.     

Glycerol valorization: New biotechnological routes

Biodiesel have drawn attention in the last decade as a renewable, biodegradable, and non-toxic fuel. Raw glycerol can become an important feedstock when biodiesel is applied on a large commercial scale. With the production of 10 kg of biodiesel from rapeseed oil, 1 kg of glycerol becomes available. Few microorganisms can be used for direct glycerol biovalorization. Yarrowia lipolytica is one of the most extensively studied “non-conventional” yeasts which is used as a model in the degradation study of hydrophobic substrates and in several other fields. Its affinity for hydrophobic compounds occurs because of the production of surface-active compounds and its differentiated cell wall. From glycerol, a hydrophobic compound easily assimilated by Y. lipolytica, it is possible to produce several substances of biotechnological importance, including biosurfactants and citric acid. Biosurfactants are potential candidates for many commercial applications in the petroleum, pharmaceutical, biomedical and food industrial processes. Citric acid has a broad use in the preparation of numerous industrial products and in many industrial areas, especially in food industry, which creates a large and ever-increasing demand for this chemical. Therefore, glycerol transformation by Y. lipolytica points to highly potential processes.     

Efficiency and pollutant emissions of an SI engine using biogas-hydrogen fuel blends: BIO60, BIO95, H20BIO60 and H20BIO95

Our planet has been experiencing abrupt climate changes in recent years. The major contributor to this phenomenon is, without doubt, emissions of gases derived from petroleum-based fuels, compared to their high consumption, especially diesel and gasoline. In Brazil, the sum of all motorized trips shows that more than half of them (60%) is based on public transport, with buses carrying 94% of all those who use this service. These vehicles, in their vast majority, use the technology of Compression Ignition (CI) engines. On the other hand, studies have shown that the country has a high biofuel production potential from various sources, such as landfills and hydroelectric plants, with an extensive production of biogas and hydrogen, that can be used, for example, in Spark Ignition (SI) engines. Nevertheless, SI engines have lower efficiency than CI engines. Part load operation of SI engines is conventionally achieved by the use of a throttle to control the airflow or air-fuel mixture into the engine. When operating at partial load the throttle causes exergy losses what affecting on decreasing engine efficiency. With the objective of analysing the emission of pollutants and the efficiency of conversion of fuel chemical energy, this work presents an analysis on the use of blends of hydrogen (H₂), biogas (BIO60) and methane (BIO95) using an SI engine. The system was operated in partial load and the addition of H₂ was an attempt to increase efficiency by reducing the pumping work through the throttle, once it was possible increasing the lambda value. The tests were performed at different ignition angles and air/fuel ratio. The value of ignition advance angle has been adjusted to obtain maximum Brake Thermal Efficiency (BTE) of the engine. It was possible to recognize that the addition of H₂ allowed the combustion limits to be extended. On the other hand, reduced values of CO and NO_x emissions could be achieved.