473 research outputs found
Immundefekte bei chronischer Rhinosinusitis : eine bedeutende und oft unterschätzte Ursache
Background Chronic rhinosinusitis (CRS) is one of the most frequent chronic diseases. Among these patients the prevalence of immune defects is higher than in the healthy general population. Methods A selective review of the literature was carried out in PubMed and Medline covering the period between 2008 and 2019. Additionally, recent German publications in journals not listed in the abovementioned databases were analyzed. Results The diagnostic workflow with respect to the immunodeficiency consists of a detailed anamnesis and physical examination, laboratory tests and the antibody reaction to polysaccharide vaccines and antigens. Beside antibiotic treatment, vaccinations and immunoglobulin replacement are available. Notwithstanding the above, functional endoscopic surgery of the paranasal sinuses should be performed according to guideline recommendations. Conclusion Patients with CRS who do not sufficiently respond to conservative and surgical treatment should be checked for underlying immunodeficiencies
Standalone hybrid power system using homer software optimal case sizing of ferraguig (North West of Algeria)
Rural areas suffer from high costs of grid extensions obliging institutions to provide for other remedies for consumers, like using generators (GE) diesel often considered as economic and reliable solutions, but at the detriment of some order environment pollution and users convenience. Furthermore, the continuous decline in GEs prices based on a renewable energy (RE) and the increasing reliability of these systems have lead to a greater use of renewable energy sources for power generation in remote areas. A property which limits the use of renewable energy is related to the variability of resources. Fluctuations in load according to annual or daily periods are not necessarily correlated to the resources. In remote areas, the preferred option is the coupling between multiple sources, such as wind turbines and solar panels, this coupling is called hybrid power system. Algeria’s geographic location presents several advantages for the development and use of renewable energy, namely, solar energy and wind energy. In addition, Algeria has huge deposits of natural gas, 98% electricity comes from gas. Therefore, currently, the production of electricity from renewable energies primarily depends on their competitiveness with economic gas. Studied technological feasibility and economic viability of the hybrid system (PV/fuel) electrification project in a school located in Ferraguig succeed to reduce high costs, energy dependence, fuel supply problem, complicated/expensive maintenance, low lifetime, impossibility of 24 hours electricity production and waste oil management issues, by using renewable energy. HOMER model is used here to size a proposed system and determine an optimum configuration
Influence de la phosphatation au zinc sur la résistance a la corrosion d’un acier au carbone en milieu maring
Zinc phosphatation influence on the resistance to corrosion of a carbonbased steel in marine mediumIn the frame of the present investigation, we have showed that the profile of the cathodic curves of a non phosphated metal, plead in favour to a kinetic profile essentially monitored by a pure diffusion. The corrosion rate, obtained from the cathodic curves as well as by a colorimetrical dosage of the dissolved iron, increases when the rotation speed of the electrode increases. Which show a diffusional control the phosphatation of the electrode does not seem to modify the cathodic curves profile. However the height of the diffusion palier depends on the thickness of the phosphatation layer. It takes values lower than those of an uncovered steel for a layer thickness of two micrometers the phosphatation layer reinforce notably the resistance to the corrosion of the internal layer which is essentially composed with iron oxides, by decreasing the corrosion rate with the increase of the layer. However, the benefical effect of the phosphatation is maximal for a thickness of three micrometers. This effect occurs also during the anodic behaviour
High Performance Multicell Series Inverter-Fed Induction Motor Drive
This document is the Accepted Manuscript version of the following article: M. Khodja, D. Rahiel, M. B. Benabdallah, H. Merabet Boulouiha, A. Allali, A. Chaker, and M. Denai, ‘High-performance multicell series inverter-fed induction motor drive’, Electrical Engineering, Vol. 99 (3): 1121-1137, September 2017. The final publication is available at Springer via DOI: https://doi.org/10.1007/s00202-016-0472-4.The multilevel voltage-source inverter (VSI) topology of the series multicell converter developed in recent years has led to improved converter performance in terms of power density and efficiency. This converter reduces the voltage constraints between all cells, which results in a lower transmission losses, high switching frequencies and the improvement of the output voltage waveforms. This paper proposes an improved topology of the series multicell inverter which minimizes harmonics, reduces torque ripples and losses in a variable-speed induction motor drive. The flying capacitor multilevel inverter topology based on the classical and modified phase shift pulse width modulation (PSPWM, MPSPWM) techniques are applied in this paper to minimize harmonic distortion at the inverter output. Simulation results are presented for a 2-kW induction motor drive and the results obtained demonstrate reduced harmonics, improved transient responses and reference tracking performance of the voltage in the induction motor and consequently reduced torque ripplesPeer reviewe
Femmes et hommes face aux grossesses non prévues au Maroc et au Sénégal
Cet article étudie la manière dont les femmes ou les couples gèrent les grossesses non prévues dans les capitales du Maroc et du Sénégal (Rabat et Dakar), deux pays soumis à des règles strictes en matière de sexualité des célibataires. Nous analysons les logiques sociales et individuelles qui prévalent à l'annonce d'une grossesse inattendue et la manière dont se prennent les décisions qui vont aboutir à la poursuite de cette grossesse ou à son interruption. Nous nous basons sur des données qualitatives tirées d'un programme financé par l'Union Européenne entre 2005 et 2009, sur l'usage de la contraception d'urgence dans les villes africaines. Nos résultats montrent qu'en dépit de programmes de planification familiale plus performants dans leur pays, les femmes de Rabat vivent leur entrée en sexualité dans des conditions difficiles. Si à Dakar la chasteté avant le mariage est prônée, le non-respect de cette règle entraîne des sanctions beaucoup moins sévères qu'au Maroc. Le choix de l'avortement en cas de grossesse non prévue évolue avec le cycle de vie des individus et selon le stade de la relation. Une pratique envisageable à un moment donné, ne l'est plus forcément à d'autres moments de la relation. Enfin, dans les deux villes, nos données révèlent une forte implication des familles dans la gestion de la formation des couples et de leur fécondité. Cette tendance apparaît cependant plus exacerbée au Maroc où les familles se mobilisent parfois âprement pour obliger ou interdire un avortement
Reliability centered maintenance optimization for power distribution systems
a b s t r a c t Today's electricity distribution systems operate in a liberalized market. These systems should therefore be able to provide electricity to customers with a high degree of reliability and be cost-effective for suppliers. RCM (Reliability Centred Maintenance) was invented by the aircraft industry in the 1960s, to organize the increasing need for maintenance for reducing costs without reducing b safety. Today RCMmethods invented by ALADON [1] are seen as very complex and are not fully accepted by the Algerian power industry. The extensive need of human and capital resources in the introduction phase is also a negative factor that could be one of the reasons of why RCM methods are not used in our branch. This article provides a discussion of the two primary objectives of RCM: to ensure safety through preventive maintenance actions, and, when safety is not a concern, preserve functionality in the most economical manner. For the power distribution systems facilities, the mission should be considered at the same level as safety
Homodyne solid-state biased coherent detection of ultra-broadband terahertz pulses with static electric fields
We present an innovative implementation of the solid-state-biased coherent detection (SSBCD) technique, which we have recently introduced for the reconstruction of both amplitude and phase of ultra-broadband terahertz pulses. In our previous works, the SSBCD method has been operated via a heterodyne scheme, which involves demanding square-wave voltage amplifiers, phase-locked to the THz pulse train, as well as an electronic circuit for the demodulation of the readout signal. Here, we demonstrate that the SSBCD technique can be operated via a very simple homodyne scheme, exploiting plain static bias voltages. We show that the homodyne SSBCD signal turns into a bipolar transient when the static field overcomes the THz field strength, without the requirement of an additional demodulating circuit. Moreover, we introduce a differential configuration, which extends the applicability of the homodyne scheme to higher THz field strengths, also leading a two-fold improvement of the dynamic range compared to the heterodyne counterpart. Finally, we demonstrate that, by reversing the sign of the static voltage, it is possible to directly retrieve the absolute THz pulse polarity. The homodyne configuration makes the SSBCD technique of much easier access, leading to a vast range of field-resolved applications
National mortality burden due to communicable, non-communicable, and other diseases in Ethiopia, 1990–2015: findings from the Global Burden of Disease Study 2015
Background: Ethiopia lacks a complete vital registration system that would assist in measuring disease burden and risk factors. We used the Global Burden of Diseases, Injuries, and Risk factors 2015 (GBD 2015) estimates to describe the mortality burden from communicable, non-communicable, and other diseases in Ethiopia over the last 25 years.
Methods: GBD 2015 mainly used cause of death ensemble modeling to measure causes of death by age, sex, and year for 195 countries. We report numbers of deaths and rates of years of life lost (YLL) for communicable, maternal, neonatal, and nutritional (CMNN) disorders, non-communicable diseases (NCDs), and injuries with 95% uncertainty intervals (UI) for Ethiopia from 1990 to 2015.
Results: CMNN causes of death have declined by 65% in the last two-and-a-half decades. Injury-related causes of death have also decreased by 70%. Deaths due to NCDs declined by 37% during the same period. Ethiopia showed a faster decline in the burden of four out of the five leading causes of age-standardized premature mortality rates when compared to the overall sub-Saharan African region and the Eastern sub-Saharan African region: lower respiratory infections, tuberculosis, HIV/AIDS, and diarrheal diseases; however, the same could not be said for ischemic heart disease and other NCDs. Non-communicable diseases, together, were the leading causes of age-standardized mortality rates, whereas CMNN diseases were leading causes of premature mortality in 2015. Although lower respiratory infections, tuberculosis, and diarrheal disease were the leading causes of age-standardized death rates, they showed major declines from 1990 to 2015. Neonatal encephalopathy, iron-deficiency anemia, protein-energy malnutrition, and preterm birth complications also showed more than a 50% reduction in burden. HIV/AIDS-related deaths have also decreased by 70% since 2005. Ischemic heart disease, hemorrhagic stroke, and ischemic stroke were among the top causes of premature mortality and age-standardized death rates in Ethiopia in 2015.
Conclusions: Ethiopia has been successful in reducing deaths related to communicable, maternal, neonatal, and nutritional deficiency diseases and injuries by 65%, despite unacceptably high maternal and neonatal mortality rates. However, the country’s performance regarding non-communicable diseases, including cardiovascular disease, diabetes, cancer, and chronic respiratory disease, was minimal, causing these diseases to join the leading causes of premature mortality and death rates in 2015. While the country is progressing toward universal health coverage, prevention and control strategies in Ethiopia should consider the double burden of common infectious diseases and non-communicable diseases: lower respiratory infections, diarrhea, tuberculosis, HIV/AIDS, cardiovascular disease, cancer, and diabetes. Prevention and control strategies should also pay special attention to the leading causes of premature mortality and death rates caused by non-communicable diseases: cardiovascular disease, cancer, and diabetes. Measuring further progress requires a data revolution in generating, managing, analyzing, and using data for decision-making and the creation of a full vital registration system in the country
Association between thyroid function and osteoarthritis:A population-based cohort study
Objectives: Previous genetic and animal studies indicated a causal role of thyroid hormones in osteoarthritis (OA), which has not been observed in the general population. We aimed to investigate whether thyroid-stimulating hormone (TSH) and free thyroxine (FT4) were associated with hand, hip, or knee OA. Methods: Participants from the Rotterdam Study with baseline TSH, FT4, and joint radiographs were included. We used multivariable regression models to investigate the association of thyroid function with the prevalence, severity, incidence, and progression of OA. We conducted stratified analyses by sex, age, body mass index (BMI) and weight-bearing physical activity. Results: Among 9054 participants included (mean age 65 years, 56.3% women), higher FT4 concentrations were associated with an increased risk of prevalent knee OA (odd ratio [OR] 1.04 per pmol/L, 95% CI 1.01–1.06, corresponding to an OR of 1.62 across the reference range [i.e., 14pmol/L changes] of FT4) and more severe knee OA. There was a positive association between FT4 and overall progression of knee OA (OR 1.03 per pmol/L, 1.00–1.07). No association of TSH with hand, hip, or knee OA was identified. Stratified analysis revealed an association between FT4 and prevalent knee OA among individuals with BMI ≥30 kg/m2 (OR 1.05 per pmol/L, 1.01–1.08) and those with high levels of weight-bearing physical activity (OR 1.05 per pmol/L, 1.01–1.10). Conclusions: Our study indicated that higher FT4 concentrations may increase the risk of knee OA. This association might be greater in individuals with extra joint loading, such as those with obesity.</p
The Metagenomics and Metadesign of the Subways and Urban Biomes (MetaSUB) International Consortium inaugural meeting report
The Metagenomics and Metadesign of the Subways and Urban Biomes (MetaSUB) International Consortium is a novel, interdisciplinary initiative comprised of experts across many fields, including genomics, data analysis, engineering, public health, and architecture. The ultimate goal of the MetaSUB Consortium is to improve city utilization and planning through the detection, measurement, and design of metagenomics within urban environments. Although continual measures occur for temperature, air pressure, weather, and human activity, including longitudinal, cross-kingdom ecosystem dynamics can alter and improve the design of cities. The MetaSUB Consortium is aiding these efforts by developing and testing metagenomic methods and standards, including optimized methods for sample collection, DNA/RNA isolation, taxa characterization, and data visualization. The data produced by the consortium can aid city planners, public health officials, and architectural designers. In addition, the study will continue to lead to the discovery of new species, global maps of antimicrobial resistance (AMR) markers, and novel biosynthetic gene clusters (BGCs). Finally, we note that engineered metagenomic ecosystems can help enable more responsive, safer, and quantified cities
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