Hypoglycaemia‐free artificial pancreas project

Driving blood glycaemia from hyperglycaemia to euglycaemia as fast as possible while avoiding hypoglycaemia is a major problem for decades for type‐1 diabetes and is solved in this study. A control algorithm is designed that guaranties hypoglycaemia avoidance for the first time both from the theory of positive systems point of view and from the most pragmatic clinical practice. The solution consists of a state feedback control law that computes the required hyperglycaemia correction bolus in real‐time to safely steer glycaemia to the target. A rigorous proof is given that shows that the control‐law respects the positivity of the control and of the glucose concentration error: as a result, no hypoglycaemic episode occurs. The so‐called hypo‐free strategy control is tested with all the UVA/Padova T1DM simulator patients (i.e. ten adults, ten adolescents, and ten children) during a fasting‐night scenario and in a hybrid closed‐loop scenario including three meals. The theoretical results are assessed by the simulations on a large cohort of virtual patients and encourage clinical trials.Inspec keywords: biochemistry, medical control systems, blood, diseases, medical computing, closed loop systems, biomedical equipment, state feedback, patient treatment, patient monitoring, biomedical measurement, physiological models, sugarOther keywords: fasting‐night scenario, hybrid closed‐loop scenario, hypoglycaemia‐free artificial pancreas project, blood glycaemia, euglycaemia, type‐1 diabetes, control algorithm, guaranties hypoglycaemia avoidance, pragmatic clinical practice, state feedback control law, required hyperglycaemia correction bolus, rigorous proof, control‐law, glucose concentration error, hypo‐free strategy control     

Removal of sulfamethoxazole from waters and wastewaters by conductive‐diamond electrochemical oxidation

BACKGROUND: Sulfamethoxazole (SMX, used as a model bacteriostatic antibiotic) is persistent to conventional biological treatments of wastewaters. In this work, conductive‐diamond electrochemical oxidation (CDEO) was found to be an effective technology for its removal from the effluents of conventional wastewater treatment plants. RESULTS: The use of CDEO has been evaluated for the removal of the antibiotic SMX from water and wastewaters. The results show that CDEO can reduce the concentration of this organic pollutant to values below 0.1 µg dm^?3. The variation of the SMX concentration during electrolysis shows a complex shape with a plateau zone that increases in size with the initial concentration of SMX. This complex trend is not observed in the changes of TOC, which seems to indicate that the CDEO of SMX solutions does not lead directly to the generation of carbon dioxide as a final product. A tentative reaction pathway has been proposed based on a thorough analysis of the reaction mixture, in which the main intermediate products were identified. The use of liquid chromatography time‐of‐flight mass spectrometry (LC‐TOFMS) allowed the identification of nine organic intermediates (with M_w 98, 108, 172, 173, 197, 203, 227, 269 and 287) during the electrolysis and the concentration of these compounds depends on the initial SMX concentration and on the current density applied. CONCLUSIONS: CDEO is able to reduce the concentration of the organic pollutant below 0.1 mg dm^?3. SMX removal is faster than that of TOC. This fact indicates the formation of reaction intermediates. Analytical techniques show that nine reaction intermediates are generated in the system, and that their concentration depends on the initial SMX concentration and on the current density used. Copyright © 2012 Society of Chemical Industry     

Adaptive Turbo Coded Modulation for Shallow Underwater Acoustic Communications

In this paper the performance of a wireless communications system over shallow underwater acoustic channels is investigated when adaptive modulation and coding techniques with receiver diversity are used. It is assumed that the communication system experiences Ricean shadowed fading. We obtain the analytical figures of the proposed rate-adaptive transmission schemes, emphasizing in the spectral efficiency and the average bit error rate. These analytical expressions are compared to Monte-Carlo simulations corroborating the analytical results.     

Cooking methods of Brassica rapa affect the preservation of glucosinolates,phenolics and vitamin C

Cooking Brassica vegetables as a domestic processing method has a great impact on health-promoting bioactive compounds: glucosinolates (GLS), flavonoids, hydroxycinnamic acids, and vitamin C. In Galicia (NorthWestern Spain), one of the most consumed horticultural crops is Brassica rapa, by using the leaves (turnip greens) and the young sprouting shoots (turnip tops) in different culinary preparations. In order to determine the effect of cooking, on turnip greens and turnip tops, bioactive GLS, flavonoids, hydroxycinnamic acids and vitamin C were analysed and simultaneously determined. The level of retention of each individual compound after cooking procedures was evaluated in the edible organs, and also in the cooking water, in order to compare their composition to a fresh uncooked control. Steaming, conventional boiling, and high-pressure cooking, traditional processing methods of this kind of vegetables, were the three domestic processing methods used in this work. Results showed that total GLS and phenolics were significantly affected by the cooking procedure and the loss rate varied among individual compounds. Steaming was the method that better preserved GLS and phenolic compounds. Conventional boiling and high-pressure cooking methods presented similar rate of losses of total GLS content (64%) and total phenolic content (more than 70%). Degradation among glucosinolate classes, aliphatic or indolic, was similar. The total flavonoids lost in turnip greens were 64% and 67% for conventional boiling and high-pressure, respectively. The main losses were caused by leaching into the cooking water. The concentration of vitamin C suffered a drastic loss in the process of sample handling and after cooking. Despite the fact that any cooking procedure affected negatively the nutritional composition of the turnip greens and tops, our results showed high retentions of individual compounds in steaming, and the lowest retentions were obtained in the traditional high-pressure cooking. High retention of health-promoting compounds in the cooking water should be considered for increasing the intake of properties of B. rapa.     

Polycrystalline fluorine-doped tin oxide as sensoring thin film in EGFET pH sensor

The Extended Gate Field Effect Transistor (EGFET) is a device composed of a conventional ion-sensitive electrode and a MOSFET device, which can be applied for the measurement of ion content in a solution. The EGFET is fabricated connecting the sensitive membrane to a commercial MOSFET. We investigated the use of fluorine-doped tin oxide films (FTO) as sensitive membrane to EGFET. The commercial FTO shows a low resistivity and a crystalline structure, both determined using conductivity set-up and X-ray diffraction experiments, respectively. So far, it has been known that an amorphous structure is desirable to obtain high sensitivity. Despite of the a crystalline structure, we have fabricated the FTO as EGFET for pH sensor and carried out experiments in order to obtain the response of the device inserted into solutions with pH values from 2 up to 12. In this range, we have quantified a sensitivity of 50 mV/pH, which may have large potential applications as pH and biosensors. In addition, both the film and the structure of the sensor are cheaper and easier to make than in common techniques.     

An integrated approach for validating micro mechanical systems based on simulation and test

Miniaturization of macroscopic mechanical systems enables the opening of new areas of application for micro technological systems. Because of technological restrictions, especially when applying miniaturized conventional manufacturing techniques, shape and material deviations cannot be scaled down in the same dimension like micro parts. Thus, the long-term objective is to ensure the functioning by appropriate design measures. In doing so, determination of the transfer behavior by modeling and simulation is required. This work presents two ways for ensuring the required properties of micro gears and describes how the results do correlate. The experimental way uses the radial composite inspection as it is used in the macroscopic world. The simulative way deploys a rolling simulation by utilization of finite element analysis. The virtual prototypes are originated on measured real test gears. When comparing experiment and simulation of the rolling behavior, in some short and long wave areas deviations can be recognized. These can be ascribed to the reduction from three to two dimensions when modeling. Other deviations might be based on inaccuracies when mounting into the test rig. In other areas quite good correlations of test and simulation could be ascertained.     

Renewable energy in a market-based economy: How to estimate its potential and choose the right incentives

A model to explain and predict market-driven investment in renewable energy capital is proposed. The model is suitable for application to the biomass, wind, solar and ocean-derived energy industries. It basically assumes that, given a set of prices and a specific technology, the marginal efficiency of capital invested in these industries only depends on the productivity of the project's site and on its energy transport distance. As suggested by traditional investment theory, the model supposes that only those projects offering marginal efficiencies of capital above the current available rate of interest would be implemented, thus demarcating a region in the productivity–energy transport distance space where all the economically viable projects should lie. By relating this region to the geographic space available for development, total potential investment can be deduced. By using cash flows defined in variable energy transport distance and mean wind speed, a case study for the Chilean wind energy industry is presented. The use of the model to analyse the effect of alternative support schemes for wind energy in Chile is briefly demonstrated. It is concluded that for increasing the area economically available for the development of new wind farms, a research and development support scheme aimed at reducing investment cost of wind turbines by 25% is equivalent to a 20% price subsidy on energy.