Lung transplantation for respiratory failure resulting from systemic disease

BACKGROUND: Lung transplantation for pulmonary failure resulting from systemic disease is controversial. We reviewed our transplant experience in patients with sarcoidosis, scleroderma, lymphangioleiomyomatosis, and graft-versus-host disease. METHODS: This retrospective review examined the outcome of 23 patients who underwent pulmonary transplantation for these systemic diseases. Group 1 included 15 patients with pulmonary hypertension who underwent transplantation (9 for sarcoidosis, 6 for scleroderma), and group 2 included 8 patients with normal pulmonary artery pressures who underwent transplantation (5 for lymphangioleiomyomatosis, 3 for graft-versus-host disease). The incidences of infection and rejection, pulmonary function, and survival were measured and compared with those of patients who underwent transplantation for isolated pulmonary disease. RESULTS: Although there were no differences in the rate of infection between patients who underwent transplantation for systemic versus isolated disease, patients with pulmonary hypertension who underwent transplantation for systemic disease had significantly lower rates of rejection. Four patients with sarcoidosis and 2 with lymphangioleiomyomatosis demonstrated recurrence in the allograft. Survival was similar between patients who underwent transplantation for systemic versus isolated disease. CONCLUSIONS: Patients with respiratory failure resulting from these systemic diseases can undergo transplantation with outcomes comparable to those obtained in patients who undergo transplantation for isolated pulmonary disease.     

Control of Grid Connected Photovoltaic Systems with Microinverters: New Theoretical Design and Numerical Evaluation

This paper addresses the problem of controlling grid connected photovoltaic (PV) systems that are driven with microinverters. The systems to be controlled consist of a solar panel, a boost dc–dc converter, a DC link capacitor, a single‐phase full‐bridge inverter, a filter inductor, and an isolation transformer. We seek controllers that are able to simultaneously achieve four control objectives, namely: (i) asymptotic stability of the closed loop control system; (ii) maximum power point tracking (MPPT) of the PV module; (iii) tight regulation of the DC bus voltage; and (iv) unity power factor (PF) in the grid. To achieve these objectives, a new multiloop nonlinear controller is designed using the backstepping design technique. A key feature of the control design is that it relies on an averaged nonlinear system model accounting, on the one hand, for the nonlinear dynamics of the underlying boost converter and inverter and, on the other, for the nonlinear characteristic of the PV panel. To achieve the MPPT objective, a power optimizer is designed that computes online the optimal PV panel voltage used as a reference signal by the PV voltage regulator. It is formally shown that the proposed controller meets all the objectives. This theoretical result is confirmed by numerical simulation tests.     

Chemical composition and antimicrobial activity of the essential oils from four Ruta species growing in Algeria

Antimicrobial properties of plants essential oils have been investigated in order to suggest them as potential tools to overcome the microbial drug resistance and the increasing incidence of food borne diseases problems. The aim of this research is to study the antibacterial and antifungal effects of four traditional plants essential oils, Ruta angustifolia, Ruta chalepensis, Ruta graveolens and Ruta tuberculata, against standard bacterial and fungal strains. The chemical compounds of the oils were examined by GC/MS. Results revealed a powerful antifungal activity against filamentous fungi. Aspergillus fumigatus and Cladosporium herbarum are the most sensitive strains to these oils with MIC values less than 3.5 μg ml⁻¹ for certain oils, reaching 7.8 μg ml⁻¹ for other. GC/MS essay exhibited ketones as the most abundant constituent of these oils except for R. tuberculata essential oil which has a completely different composition, monoterpenes alcohols being the most abundant. These compositions explain their potential antifungal activity.     

Heat transfer coefficient and thermal losses of solar collector and Nusselt number correlation for rectangular solar air heater duct with longitudinal fins hold under the absorber plate

An experimental investigation has been carried out for a series of system and operating parameters in order to analyze the effect of mass flow rate on heat transfer and Nusselt number characteristics in solar air heater. Experiments are performed at different air mass flow rates; varying from 0.012 to 0.016 kg/s, about hot summer days of Mai 2012. Hourly values of global solar radiation and some meteorological data (temperature, wind speed, relative humidities, etc.) for measuring days are obtained from the Biskra city of Algeria. The experiments encompassed the flow Reynolds number in the range 965.48–1301.4. Longitudinal fins were used inferior the absorber plate for an increase the heat exchange and render the flow fluid in the channel uniform. The effects of mass flow rate of air on the outlet temperature, Nusselt Number, Reynolds Number, Prandtl Number, the heat transfer in the thickness and length of the solar air collector were studied. For this effect was have created a new correlation correspondent of solar air collector with using fins it was written Nu = κ₀Re^1.36Pr^?0.68exp(0.342m)h ^[?0.018Pr].     

Prediction of the theoretical and semi-empirical model of ambient temperature

It is well known that the ambient temperature is a sensitive parameter which has a great effect on biology, technology, geology and even on human behavior. A prediction is a statement about an uncertain event. It is often, but not always, based upon experience or knowledge. Although guaranteed accurate information about the future is in many cases impossible, prediction can be useful to assist in making plans about possible developments. As a result, temperature profiles can be developed which accurately represent the expected ambient temperature exposure that this environment experiences during measurement. The ambient temperature over time is modeled based on the previous T _min and T _max data and using a Lagrange interpolation. To observe the comprehensive variation of ambient temperature the profile must be determined numerically. The model proposed in this paper can provide an acceptable way to measure the change in ambient temperature.     

Parameter identification of ZnO surge arrester models based on genetic algorithms

The correct and adequate modelling of ZnO surge arresters characteristics is very important for insulation coordination studies and systems reliability. In this context many researchers addressed considerable efforts to the development of surge arresters models to reproduce the dynamic characteristics observed in their behaviour when subjected to fast front impulse currents. The difficulties with these models reside essentially in the calculation and the adjustment of their parameters.     

Results of heart transplantation by extending recipient selection criteria

From November 1985 to July 1993, 29 out of 241 patients (12%) who underwent heart transplantation (HTx) at our institution had one or more "classical" contraindications to HTx: age > or = 60 years (20 patients); insulin-dependent diabetes mellitus (5 patients); irreversible renal failure requiring combined heart-kidney transplantation (2 patients); previous surgery for malignancy (1 patient); familial hypercholesterolemia (1 patient) and active systemic infection (1 patient). The main indication for HTx was ischemic cardiomyopathy (21 patients, 61%). Immunosuppression regimen consisted of Cyclosporine and Azathioprine, oral prednisone being subsequently added in 6 patients because of persistent rejection. There were 2 perioperative deaths and one late death. Follow-up ranged from 1 to 88 months (mean, 28 +/- 20) with an actuarial survival at 5 years of 85 +/- 8%. Annual cardiac catheterization demonstrated normal graft function and coronary arteries in all. No significant differences in survival, incidence of rejection and infection, renal function and duration of hospitalization were found when these patients were compared with those with no contraindications to HTx. In conclusion, HTx can be performed with good early clinical results in selected patients with "classical" contraindications to HTx; longer follow-up, however, is needed to confirm whether extension of the recipient selection criteria justified.     

Modeling and design of printed antennas using neural networks

A single neural network is developed to model the resonant frequency of rectangular patch printed on uniaxially anisotropic substrate with air gap using effective parameters in conjunction with spectral dyadic Green's function. Also, the strength of ANN models in antenna design is demonstrated by considering two case studies: the design of circular patch antenna and planar inverted‐F antenna. Results show good agreement with literature. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011.     

A piecewise switched linear approach for traffic flow modeling

Traffic modeling is a key step in several intelligent transportation systems (ITS) applications. This paper regards the traffic modeling through the enhancement of the cell transmission model. It considers the traffic flow as a hybrid dynamic system and proposes a piecewise switched linear traffic model. The latter allows an accurate modeling of the traffic flow in a given section by considering its geometry. On the other hand, the piecewise switched linear traffic model handles more than one congestion wave and has the advantage to be modular. The measurements at upstream and downstream boundaries are also used in this model in order to decouple the traffic flow dynamics of successive road portions. Finally, real magnetic sensor data, provided by the performance measurement system on a portion of the Californian SR60-E highway are used to validate the proposed model.     

Increasing end‐to‐end fairness over IEEE 802.11e‐based wireless mesh networks

In this paper, we discuss the issue of fairness in the IEEE802.11e over wireless mesh networks. Fairness is an important factor that we have to achieve before talking about QoS. Inspired by social networks approximations, and to achieve fairness and provide QoS by regulating heterogeneous traffic, we extended the original IEEE802.11e protocol by introducing a new algorithm based on the ‘token bucket’ concept. We also treat the problem of exposed/hidden nodes. Simulation results show that the proposed approach offers better performance than the IEEE802.11e one. Copyright © 2011 John Wiley & Sons, Ltd.