62 research outputs found

    Potential-pH Diagrams of Iron in Concentrated Aqueous LiBr Solutions at 25°C

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    [EN] Potential-pH diagrams of iron are developed in aqueous LiBr solutions with concentrations of 400 g/L, 700 g/L, 850 g/L, and 992 g/L LiBr at 25 degrees C, which are common concentrations in different parts of absorption machines. Comparison of the potential-pH diagrams of iron in the absence and the presence of concentrated aqueous LiBr solutions shows that the corrosion area at acid, neutral, and weak alkaline pH extends to lower potentials and higher pH values with the increase of LiBr concentration, as a result of formation of the aqueous species FeBr2(aq) and FeBr3(aq) and destabilization of the solid species Fe, Fe(OH)(2)(s), Fe3O4, and Fe2O3.The authors acknowledge the "Programa de Apoyo a la Investigacion y Desarrollo (PAID-06-10) de la UPV" for the support of this work, Antonio Juncos for his assistance in plotting the diagrams, and Dr. M. Asuncion Jaime for her translation assistance.Muñoz-Portero, M.; Nachiondo Farinós, TDM.; Blasco-Tamarit, E.; Vicent-Blesa, A.; Garcia-Anton, J. (2018). Potential-pH Diagrams of Iron in Concentrated Aqueous LiBr Solutions at 25°C. Corrosion. 74(10):1102-1116. https://doi.org/10.5006/2865S11021116741

    Production of fructooligosaccharides and b-fructofuranosidase by batch and repeated batch fermentation with immobilized cells of Penicillium expansum

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    The production of fructooligosaccharides (FOS) and b-fructofuranosidase (FFase) by immobilized cells of Penicillium expansum was evaluated. In an initial stage, different low-cost materials including synthetic fiber, polyurethane foam, stainless steel sponge, loofah sponge, and cork oak were tested as carrier for the fungus immobilization. Additionally, the influence of the inoculum age (1 or 3 weeks) on cells immobilization, FOS and FFase production was also verified. Synthetic fiber and polyurethane foam were the best materials for P. expansum immobilization (2.21 and 1.98 g/g carrier, respectively) and FOS production (120.3 and 104.8 g/l), and gave also high results of FFase activity (23.01 and 32.42 U/ml). Then, the production of FOS and FFase by repeated batch fermentation with P. expansum immobilized on synthetic fiber was studied, aiming to improve the batch fermentation results. The results obtained in this stage were very promising with FOS yields of 87, 72, and 44 %, in the 3 initial cycles (60 h), respectively; the FFase activity was constant throughout the process (6 cycles, 96 h). Repeated batch fermentation with immobilized cells of P. expansum was found as being a technology with great potential for FOS and FFase production on industrial scaleThe financial support from FCT, the Portuguese Foundation for Science and Technology (research grant SFRH/BPD/38212/2007) is gratefully acknowledged

    Genetic diversity and transmissibility of imported Plasmodium vivax in Qatar and three countries of origin

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    Malaria control program in the Arabian Peninsula, backed by adequate logistical support, has interrupted transmission with exception of limited sites in Saudi Arabia and sporadic outbreaks in Oman. However, sustained influx of imported malaria represents a direct threat to the above success. Here we examined the extent of genetic diversity among imported P. vivax in Qatar, and its ability to produce gametocytes, compared to parasites in main sites of imported cases, the Indian subcontinent (india) and East Africa (Sudan and Ethiopia). High diversity was seen among imported P. vivax in Qatar, comparable to parasites in the Indian subcontinent and East Africa. Limited genetic differentiation was seen among imported P. vivax, which overlapped with parasites in India, but differentiated from that in Sudan and Ethiopia. Parasite density among imported cases, ranged widely between 26.25–7985934.1 Pv18S rRNA copies/µl blood, with a high prevalence of infections carried gametocytes detectable by qRT-PCR. Parasitaemia was a stronger predictor for P. vivax gametocytes density (r = 0.211, P = 0.04). The extensive diversity of imported P. vivax and its ability to produce gametocytes represent a major threat for re-introduction of malaria in Qatar. The genetic relatedness between P. vivax reported in Qatar and those in India suggest that elimination strategy should target flow and dispersal of imported malaria into the region

    Identifying Live Bird Markets with the Potential to Act as Reservoirs of Avian Influenza A (H5N1) Virus: A Survey in Northern Viet Nam and Cambodia

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    Wet markets are common in many parts of the world and may promote the emergence, spread and maintenance of livestock pathogens, including zoonoses. A survey was conducted in order to assess the potential of Vietnamese and Cambodian live bird markets (LBMs) to sustain circulation of highly pathogenic avian influenza virus subtype H5N1 (HPAIV H5N1). Thirty Vietnamese and 8 Cambodian LBMs were visited, and structured interviews were conducted with the market managers and 561 Vietnamese and 84 Cambodian traders. Multivariate and cluster analysis were used to construct a typology of traders based on their poultry management practices. As a result of those practices and large poultry surplus (unsold poultry reoffered for sale the following day), some poultry traders were shown to promote conditions favorable for perpetuating HPAIV H5N1 in LBMs. More than 80% of these traders operated in LBMs located in the most densely populated areas, Ha Noi and Phnom Penh. The profiles of sellers operating at a given LBM could be reliably predicted using basic information about the location and type of market. Consequently, LBMs with the largest combination of risk factors for becoming virus reservoirs could be easily identified, potentially allowing control strategies to be appropriately targeted. These findings are of particular relevance to resource-scarce settings with extensively developed LBM systems, commonly found in South-East Asia

    Navy labs play public health role

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    A United States network of laboratories, initially created to protect the health of US service personnel by doing local research and disease surveillance, has become a major public health presence in the developing countries where it operates
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