381 research outputs found
Legal and Ethical Implications of U.S. and Canadian Vaccine Contracts: The Impact of Vaccine Nationalism on the Global Pandemic Response
This note explores the COVID-19 vaccine contracts between the U.S. and Canada and the impact of these types of agreements on the global pandemic response. These “pre-purchases,” many of which were executed before the development of a vaccine, have afforded a select few nations the opportunity to stockpile vaccines, while other nations with fewer resources are unable to secure any doses. An effective method to counter the effects of the pandemic is the creation of a global vaccine network that provides equitable access to vaccine doses for nations in need. COVAX was launched to ensure that lower and middle-income nations have the opportunity to purchase vaccine doses at reduced costs for their respective populations. This initiative offers a realistic solution to shortening the timeline of the COVID-19 pandemic and bringing the global population closer to herd immunity
ÉTUDE DES POLLUANTS CONTENUS DANS LES LIXIVIATS ISSUS DE LA DÉCHARGE PUBLIQUE DE LA VILLE DE MEKNES (MAROC)
The rationale behind this study is to evaluate the impact of leachate resulting from the public landfill of Meknès city (MOROCCO), on the environment and more specifically on the waters of the aquifer. For this, a spatio-temporal monitoring of Nitrites, Nitrates, total germs, Sulfito reducing bacteria, Salmonella was performed at eight stations during the four seasons of the year 2013, in order to make a comparison between the pollution load of the leachate and, the possibility that juice discharge contamins groundwater. However, other different sampling point, are believed to be at the beginning of their infection. As to test this, we analyzed seven samples (water wells and springs) around the landfill by physico-chemical and bacteriological analyzes. We confirm in this study that the marl is a temporary powerful obstacle, in contrast with permanent increasing pollution, generated by the decomposition of waste in landfill of Meknes city
First principles calculations of electronic and optical properties for mixed perovskites: Ba (1-x) Ca (x) TiO 3 and Ba (1-x) Sr (x) TiO 3 (x=0.4, 0.6)
International audienceThe effect of Ca and Sr-doping on the structural electronic and optical properties of the cubic Ba1-xCaxTiO3 and Ba1-xSrxTiO3 (x=0.4, 0.6) mixed crystals was investigated using first-principles calculations based on density functional theory (DFT). The calculated band structures based on the optimized geometry of the cell for the solid solutions show an indirect band gap character at M-points, with low energy dispersion along height symmetry directions in the Brillouin zone. The band gaps increase with Ca and Sr concentrations. The total and partial densities of states were analyzed to examine the contribution of different orbitals to the maximum of valence band and the minimum of the conduction band. The optical properties such as reflectivity, energy loss, refractive index and extinction coefficient were studied
The effectiveness of Doppler controlled hemorrhoidal artery ligation based on preliminaries results
In this work, we discuss the preliminary results of the effectiveness of the hemorrhoidal artery ligation under control Doppler as a new technique for the treatment of hemorrhoids. We report the results of patients with hemorrhoids we have followed over a period of one year who were treated with HAL Doppler. The intra-and postoperative complications were monitored. Patient follow-up was established on the immediate postoperative period, after one month, six months and one year of evolution. Monitoring parameters were both objective (prolapse) and subjective (pain, discomfort, bleeding, satisfaction). 120 patients, all stages combined, were treated with HAL Doppler. The pain is easily controlled with painkillers. Residual rectal bleeding was noted in 3% of the cases. In addition, there was one case of recurrent prolapse which underwent reoperation. After one month, 86,5 % patients were satisfied. The hemorrhoidal artery ligation under control Doppler is an easy technique, well accepted by patients who are increasingly demanding it. It is less invasive, less painful and gives fewer complications. It is not only effective for stage III and IV hemorrhoids for which the effect is spectacular but also for stages I and II symptoms, which can expand its indications.Key words: Symptomatic hemorrhoids, Hemorrhoidal Artery Ligation, Doppler, mucopexy
Effects of Sodium Bicarbonate and photoperiod on Cell Growth and morphology of Isochrysis galbana
Microalgae play a vital role in many aquaculture feed application processes. Maintaining a microalgae production facility has been estimated to account for an average of 30 % and up to 60 % of the total budget of aquaculture hatcheries, despite several research programs and global efforts to reduce production costs of algal biomass. The use of bicarbonate as carbon inorganic to produce microalgae biomass for bivalve hatcheries was proposed as an alternative to reduce this cost. The focus of this investigation is characterization of the interaction of bicarbonate-based microalgae cultivation and photoperiod on the growth rate and production of brown microalgae Isochrysis galbana. The salt was provided to the cultures at the final concentration from 0.5 to 2.5 g L-1. Concerning photoperiod, two cycles of light:dark (6:18 and 12:12) were studied under light intensity at 160 µmol m-2 s-1. The growth rate of Isochrysis galbana showed values significantly higher in the culture supplemented with 0.5 and 1 g L-1 of NaHCO3 respectively under cycles 6L:18D and 12L:12D. Bicarbonate administration leads to a significant increase in cellular size at the stationary phase, probably related to starch or lipid accumulation. This study proved that the addition of bicarbonate is a viable strategy to enhance the production of microalgae and reduce production costs
ÉTUDE DES POLLUANTS CONTENUS DANS LES LIXIVIATS ISSUS DE LA DÉCHARGE PUBLIQUE DE LA VILLE DE MEKNES (MAROC)
The rationale behind this study is to evaluate the impact of leachate resulting from the public landfill of Meknès city (MOROCCO), on the environment and more specifically on the waters of the aquifer. For this, a spatio-temporal monitoring of Nitrites, Nitrates, total germs, Sulfito reducing bacteria, Salmonella was performed at eight stations during the four seasons of the year 2013, in order to make a comparison between the pollution load of the leachate and, the possibility that juice discharge contamins groundwater. However, other different sampling point, are believed to be at the beginning of their infection. As to test this, we analyzed seven samples (water wells and springs) around the landfill by physico-chemical and bacteriological analyzes. We confirm in this study that the marl is a temporary powerful obstacle, in contrast with permanent increasing pollution, generated by the decomposition of waste in landfill of Meknes city
Plastic and Reconstructive Surgery Advance Online Article
Background: The aim of this study was to evaluate the efficacy, safety profile, and complications associated with mandibular distraction osteogenesis performed in infants weighing less than 4 kg with Robin sequence.
Methods: An 11-year retrospective review of all infants (younger than 6 months) with mandibular distraction osteogenesis–treated Robin sequence was performed. Patients weighing less than 4 kg (experimental) and 4 kg or more (control) who underwent mandibular distraction osteogenesis were compared. Demographics, medical comorbidities, improvement in apnea/hypopnea index, need for tracheostomy, repeated distraction, and complications were evaluated.
Results: One hundred twenty-one patients underwent mandibular distraction osteogenesis. Eighty-one patients weighed less than 4 kg and 40 weighed 4 kg or more. The mean follow-up was 2.8 years in patients weighing less than 4 kg and 3.0 years in the control group. Mean age and weight at the time of distraction were 23 days and 3.1 kg, respectively, in the study group; and 2.7 years and 11 kg, respectively, in the control group. There was no significant difference in success of mandibular distraction osteogenesis to treat airway obstruction in the group weighing less than 4 kg compared with the control group (92.6 percent versus 88.9 percent; p = 0.49). The most common complication in each group was surgical-site infection (9.9 percent and 20.0 percent; p = 0.15). Overall complication rates were similar between the two groups (17.3 percent versus 25.0 percent; p = 0.34). The rates of repeated distraction were similar between the two groups (6.3 percent and 13.5 percent; p = 0.28).
Conclusions: Mandibular distraction osteogenesis is a safe and effective treatment modality for infants weighing less than 4 kg with severe airway obstruction. The efficacy, safety, and complication profiles are not significantly different from those of larger patients.
CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III
Effects of Grain Refining on Columnar-to-Equiaxed Transition in Aluminum Alloys
The effects of grain refining in ultra-pure aluminum, commercially pure aluminum (1050), and Al-7%Si binary alloy were investigated, using different additions of Al-10%Ti, Al-5%Ti-1%B, and Al-4%B master alloys. Thermal analysis and metallography were used to assess the variations in microstructure resulting from these additions, at solidification rates of 0.8°C/s and ~10°C/s. The results revealed that addition of Al-4%B to ultra-pure aluminum forms AlB12 and AlB2 which have no grain-refining effect. Without grain refiner addition, the pure aluminum microstructure exhibits a mixture of columnar and equiaxed grains. Addition of 30ppm Ti is sufficient to promote equiaxed grains at ~10°C/s but requires addition of 1000 ppm B to obtain similar results at 0.8°C/s. Increasing the Si content to 7% reduces the initial grain size of pure aluminum from 2800 μm to ~1850 μm, and further to 450 μm with ddition of ~500ppm B. In commercial aluminum, the B reacts with traces of Ti forming Al3Ti and TiB2 phases which are active grain-refiners. In Al-7%Si, Ti reacts with Si forming (Al,Si)2Ti phase, which is a poor refining agent. This phenomenon is termed poisoning. No interaction between B and Si is observed in the commercial aluminum or Al-7%Si alloy when B is added
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