4 research outputs found

    Design and Implementation of High Gain High Stability Power Amplifier for X band Radar Transmitter

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    Power Amplifier (PA) is an important part of transmitter鈥檚 front end. The main function is to amplify extremely high gain high stability power amplifier for radar transmitter. In this paper, PA used in transmitter portion of radar is designed and implemented. DC biasing, stability checking and input/output impedance matching of the RF transistor design procedures are considered. The stability analysis of power amplifiers is one of the most critical and the most challenging aspects of power amplifier design. Stability analysis is shown an analysis technique, which accurately predicts the oscillations in power amplifiers. The power amplifier (PA) design project is simulated with Electronic Workbench Multisim8 software. The simulation results are considered on the frequency used in 9.35GHz of X-band

    Effectiveness of five artemisinin combination regimens with or without primaquine in uncomplicated falciparum malaria: an open-label randomised trial

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    BACKGROUND: Artemisinin-combination therapy (ACT) is recommended as first-line treatment of falciparum malaria throughout the world, and fixed-dose combinations are preferred by WHO; whether a single gametocytocidal dose of primaquine should be added is unknown. We aimed to compare effectiveness of four fixed-dose ACTs and a loose tablet combination of artesunate and mefloquine, and assess the addition of a single gametocytocidal dose of primaquine. METHODS: In an open-label randomised trial in clinics in Rakhine state, Kachin state, and Shan state in Myanmar (Burma) between Dec 30, 2008, and March 20, 2009, we compared the effectiveness of all four WHO-recommended fixed-dose ACTs (artesunate-mefloquine, artesunate-amodiaquine, dihydroartemisinin-piperaquine, artemether-lumefantrine) and loose artesunate-mefloquine in Burmese adults and children. Eligible patients were those who presented to the clinics with acute uncomplicated Plasmodium falciparum malaria or mixed infection, who were older than 6 months, and who weighed more than 5 kg. Treatments were randomised in equal numbers within blocks of 50 and allocation was in sealed envelopes. All patients were also randomly assigned to receive either a single dose of primaquine 0路75 mg base/kg or not. Patients were followed up for 63 days. Treatment groups were compared by analysis of variance and multiple logistic regression. The primary outcome was the 63 day recrudescence rate. This study is registered with clinicaltrials.gov, number NCT00902811. FINDINGS: 155 patients received artesunate-amodiaquine, 162 artemether-lumefantrine, 169 artesunate-mefloquine, 161 loose artesunate-mefloquine, and 161 dihydroartemisinin-piperaquine. By day 63 of follow-up, 14 patients (9路4%; 95% CI 5路7-15路3%) on artesunate-amodiaquine had recrudescent P falciparum infections, a rate significantly higher than for artemether-lumefantrine (two patients; 1路4%; 0路3-5路3; p=0路0013), fixed-dose artesunate-mefloquine (0 patients; 0-2路3; p<0路0001), loose artesunate-mefloquine (two patients; 1路3%; 0路3-5路3; p=0路0018), and dihydroartemisinin-piperaquine (two patients 1路3%; 0路3-5路2%; p=0路0012). Hazard ratios for re-infection (95% CI) after artesunate-amodiaquine were 3路2 (1路3-8路0) compared with the two artesunate-mefloquine groups (p=0路01), 2路6 (1路0-6-0) compared with artemether-lumefantrine (p=0路04), and 2路3 (0路9-6路0) compared with dihydroartemisinin-piperaquine (p=0路08). Mixed falciparum and vivax infections were common: 129 (16%) had a mixed infection at presentation and 330 (41%) patients had one or more episodes of Plasmodium vivax infection during follow-up. The addition of a single dose of primaquine (0路75 mg/kg) reduced P falciparum gametocyte carriage substantially: rate ratio 11路9 (95% CI 7路4-20路5). All regimens were well tolerated. Adverse events were reported by 599 patients, most commonly vomiting and dizziness. Other side-effects were less common and were not related to a specific treatment. INTERPRETATION: Artesunate-amodiaquine should not be used in Myanmar, because the other ACTs are substantially more effective. Artesunate-mefloquine provided the greatest post-treatment suppression of malaria. Adding a single dose of primaquine would substantially reduce transmission potential. Vivax malaria, not recurrent falciparum malaria, is the main complication after treatment of P falciparum infections in this region. FUNDING: M茅decins sans Fronti猫res (Holland) and the Wellcome Trust Mahidol University Oxford Tropical Medicine Research Programme

    Biodiversity conservation in a changing climate: a review of threats and implications for conservation planning in Myanmar

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    High levels of species richness and endemism make Myanmar a regional priority for conservation. However, decades of economic and political sanctions have resulted in low conservation investment to effectively tackle threats to biodiversity. Recent sweeping political reforms have placed Myanmar on the fast track to economic development-the expectation is increased economic investments focused on the exploitation of the country's rich, and relatively intact, natural resources. Within a context of weak regulatory capacity and inadequate environmental safeguards, rapid economic development is likely to have far-reaching negative implications for already threatened biodiversity and natural-resource-dependent human communities. Climate change will further exacerbate prevailing threats given Myanmar's high exposure and vulnerability. The aim of this review is to examine the implications of increased economic growth and a changing climate within the larger context of biodiversity conservation in Myanmar. We summarize conservation challenges, assess direct climatological impacts on biodiversity and conclude with recommendations for long-term adaptation approaches for biodiversity conservation
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