92 research outputs found

    Synthesis and characterization of M(II) phosphonates (M = Fe, Co, Zn, Mn) as precursors for PEMFCs electrocatalysts

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    Metal phosphonates are promising precursors for applications such as proton conductivity [1] and catalysis [2]. Specifically, upon calcination metal polyphosphates are generated that can be used as non-noble metal alternatives [3] to the highly expensive commercial catalysts (Pt) for proton exchange membrane fuel cells (PEMFCs). In this work, we present the synthesis and characterization of metal polyphosphates obtained from transition divalent metal phosphonates (M= Fe, Mn, Co and Zn) both as monometallic and bimetallic systems (solid solutions). For the preparation of the metal phosphonate precursors, two types of organic linkers were selected, i.e. 2-R,S-hydroxiphosphonoacetic acid [HO3PCH(OH)COOH, HPAA] and nitrilotrismethylenephosphonic acid [N(CH2PO3H2)3, ATMP]. The as synthesized compounds were calcined between 700 and 1000 ºC under N2. Depending on the metal/phosphorous molar ratio in the precursor phases, different compositions were found, the corresponding metal pyrophosphate being the major component according to the crystallographic data. Interestingly, in most of cases the solid solutions were preserved in the final product, for instance Fe-Mn, Fe-Co and Fe-Zn. All calcined materials have been also characterized by XPS, SEM/EDS, FTIR-Raman.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Temperature Monitoring and Forecast System in Remote Areas with 4.0G LTE Mobile Technologies

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    The need to monitor areas of high risk in terms of temperature indexes has included two important elements for its compliance: monitoring and forecast of records in an environment. Performing this procedure manually is inefficient as it provides a flat perspective and can’t predict the state of the environment with rigor. Software systems are contemporary elements in constant refinement, which satisfy emerging needs of a context, so that, in relation to monitoring and forecast an environment, it allows a sophisticated automation of the process, and that tends to lead to a better supervision of the risks in the environment. This article presents a proposal for the supervision of high-risk areas, through temperature registers, manageable through the design of a software system with the implementation of mobile 4.0G LTE technologies, aimed at efficiency and effectiveness in the notification of environmental status. Finally, I conclude with a remote temperature monitoring and forecast system, using mobile technologies, with a fuzzy logic prediction system with a quadratic error not greater than 2.6%, that is, on a fuzzy algebra system whose Numerical calculation does not exceed this error value in comparison with actual values; At the same time that the future works are presented from the approach of the research that is postulated, according to the emergence of new perspectives related to this developing software system

    A Study on the Phytotoxic Potential of the Seasoning Herb Marjoram (Origanum majorana L.) Leaves

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    In the search of new alternatives for weed control, spices appear as an option with great potential. They are rich in bioactive natural products and edible, which might minimize toxicity hazard. Marjoram (Origanum majorana L.) is an aromatic herb that has been widely employed as a seasoning herb in Mediterranean countries. Although marjoram boasts a plethora of therapeutic properties (painkiller, antibiotic, treatment for intestinal disorders, etc.), the potential for its extracts for weed control is still to be more thoroughly explored. In order to determine their phytotoxic potential, marjoram leaves were subjected to different bioguided extraction processes, using water, ethyl acetate, acetone or methanol. The most active extract (acetone) was sequentially fractionated to identify its most active compounds. This fractionation led to the isolation and identification of 25 compounds that were classified as monoterpenes, diterpenes or flavonoids. Among them, a new compound named majoradiol and several compounds are described in marjoram for the first time. The phytotoxicity of the major compounds to etiolated wheat coleoptiles was compared against that of the commercial herbicide (Logran(R)), with similar or higher activity in some cases. These results confirm the extraordinary potential of the extracts from this edible plant to develop safer and more environmentally friendly herbicides

    Resistência antimicrobiana nos principais recursos aquícolas dos departamentos de Tumbes, Piura, San Martin e Puno

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    [Objective] The objective of this study was to analyze antimicrobial resistance in Peruvian aquaculture. [Methodology] An observational, descriptive study was carried out. Samples of Argopecten purpuratus, Oncorhynchus mykiss, Oreochromis niloticus and Litopenaeus vannamei were included. The bacteria Enterococcus spp., Salmonella spp., Escherichia coli, Vibrio parahaemolyticus, Aeromonas spp., and Flavobacterium psychrophilum were isolated. Antibiotic resistance was evaluated using antibiograms, and resistant samples were sequenced to identify antimicrobial resistance genes. Absolute and percentage frequencies were calculated. In addition, Wald, Clopper-Pearson, and pooled prevalence confidence intervals were estimated. [Results] In the case of A. purpuratus, 22.2% (95% CI:2.81-60.00) of the E. coli samples were resistant to oxytetracycline. Resistant samples were found in 4.44% (n=2) of the aquaculture production centers (APCs). In O. mykiss, 88.89% (95% CI:51.16-99.72) of the Enterococcus spp. were resistant to fosfomycin and oxytetracycline. Resistant samples were found in12.96% of the APCs (n=7). Regarding O. niloticus, 47.31% (95% CI: 37.16-57.46) of the E. coli samples were resistant to oxytetracycline>ampicilline>chloramphenicol>fosfomycin and azithromycin. Resistant samples were encountered in 50% of the APCs (n=19). In addition, 89.36% (95% CI:80.55-98.18) of the Enterococcus spp. were resistant to Fosfomycin> chloranphenicol and colistin> oxytetracycline>azithromycin>ampicilline; resistant samples were found in 36.84% of the APCs (n=14). In L. vannamei, 87.11% (95% CI:83.00-91.21) of the Enterococcus spp. samples were resistant to Fosfomycin> colistin> oxytetracycline> azithromycin>ampicilline and resistant samples were found in 100% of the APCs (n=33). Likewise, 35.05% (95% CI:29.74-40.23) of the V. parahaemolyticus samples were resistant to ampicilline>fosfomycin>oxytetracycline>azithromycin>eritromicine>enrofloxacin> ampicilline> chloranfhenicol. Resistant samples were found in 78.79% (n=26) of the APCs. [Conclusions] The percentage of APCs with O. niloticus and L. vannamei showed that antimicrobial resistance was high.[Objetivo] El objetivo fue analizar la resistencia antimicrobiana en la acuicultura peruana. [Metodología] Se realizó un estudio observacional, descriptivo. Se incluyeron muestras de las especies Argopecten purpuratus, Oncorhynchus mykiss, Oreochromis niloticus y Litopenaeus vannamei. Se aislaron bacterias del género Enterococcus spp., Salmonella spp. y Aeromonas spp., y especies de Escherichia coli, Vibrio parahaemolyticus, y Flavobacterium psychrophilum. La resistencia antimicrobiana fue evaluada mediante antibiograma y las muestras resistentes fueron secuenciadas para identificar genes de resistencia antimicrobiana. Se calculó la frecuencia absoluta y porcentual, además, se estimaron los intervalos de confianza de Wald, de Clopper-Pearson, y prevalencia agrupada. [Resultados] Respecto a A. purpuratus, el 22,2 % (IC95%:2,81-60,00) de las muestras de E. coli fueron resistentes a oxitetraciclina. Estas pertenecían al 4,44 % (n=2) de los centros de producción acuícola (CPA). En O. mykiss, el 88,89% (IC95%:51,16-99,72) de las muestras de Enterococcus spp. fueron resistentes a fosfomicina y oxitetraciclina. Estas pertenecían al 12,96 % de los CPA (n=7). En referencia a O. niloticus, el 47,31 % (IC95%: 37,16-57,46) de las muestras de E. coli fueron resistentes oxitetraciclina>ampicilina>cloranfenicol>fosfomicina y azitromicina. Estas pertenecían al 50 % de los CPA (n=19). Además, 89, 36% (IC95 %:80,55-98,18) de las muestras de Enterococcus spp. fueron resistentes a fosfomicina>cloranfenicol y colistina>oxitetraciclina>azitromicina>ampicilina; estas pertenecían al 36,84 % de los CPA (n=14). En L. vannamei, el 87,11 % (IC95%:83,00-91,21) de las muestras de Enterococcus spp. fueron resistentes a fosfomicina>colistina>oxitetraciclina>azitromicina>eritromicina>enrofloxacino> ampicilina>cloranfenicol y estas pertenecían al 100 % de los CPA (n=33). Asimismo, 35,05 % (IC95%: 29,74-40,23) de las muestras de V. parahaemolyticus fueron resistentes a ampicilina>fosfomicina>colistina>oxitetraciclina>azitromicina. Estas pertenecían al 78,79 % (n=26) de los CPA. [Conclusiones] El porcentaje de CPA de O. niloticus y L. vannamei, mostraron mayor resistencia antimicrobiana del estudio.[Objetivo] O objetivo foi analisar a resistência antimicrobiana na aquicultura peruana. [Metodologia] Foi realizado um estudo observacional, descritivo. Foram incluídas amostras das espécies Argopecten purpuratus, Oncorhynchus mykiss, Oreochromis niloticus e Litopenaeus vannamei.   Foram isoladas bactérias dos gêneros Enterococcus spp., Salmonella spp., Aeromonas spp., e espécies de Escherichia coli, Vibrio parahaemolyticus e Flavobacterium psychrophilum. A resistência antimicrobiana foi avaliada por meio de antibiograma, e amostras resistentes foram sequenciadas para identificar genes de resistência antimicrobiana. Foram calculadas as frequências absoluta e percentual, além dos intervalos de confiança de Wald, Clopper-Pearson e as prevalências agrupadas. [Resultados] Em relação a A. purpuratus, 22,2% (IC 95%: 2,81-60,00) das amostras de E. coli foram resistentes à oxitetraciclina. Estes pertenciam a 4,44 % (n=2) dos centros de produção aquícola (CPA). Em O. mykiss, 88,89% (IC 95%: 51,16-99,72) das amostras de Enterococcus spp. foram resistentes à fosfomicina e oxitetraciclina.  Estas pertenciam a 12,96% das CPAs (n=7). Em relação a O. niloticus, 47,31 % (IC 95%: 37,16-57,46) das amostras de E. coli foram resistentes à oxitetraciclina>ampicilina>cloranfenicol>fosfomicina e azitromicina. Estas pertenciam a 50% das CPAs (n=19). Além disso, 89,36% (IC95%: 80,55-98,18) das amostras de Enterococcus spp. foram resistentes a fosfomicina>cloranfenicol e colistina>oxitetraciclina>azitromicina>ampicilina; estas pertenciam a 36,84% das CPAs (n=14). Em L. vannamei, 87,11% (IC 95%: 83,00-91,21) das amostras de Enterococcus spp foram resistentes à fosfomicina>colistina>oxitetraciclina>azitromicina>eritromicina>enrofloxacina> ampicilina>cloranfenicol e pertenciam a 100% das CPAs (n=33). Além disso, 35,05% (IC 95%: 29,74-40,23) das amostras de V. parahaemolyticus foram resistentes à ampicilina>fosfomicina>colistina>oxitetraciclina>azitromicina. Estas pertenciam a 78,79% (n=26) das CPAs. [Conclusões] A porcentagem de CPA de O. niloticus e L. vannamei, mostrou maior resistência antimicrobiana do estudo

    Specific Cell Targeting Therapy Bypasses Drug Resistance Mechanisms in African Trypanosomiasis

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    African trypanosomiasis is a deadly neglected disease caused by the extracellular parasite Trypanosoma brucei. Current therapies are characterized by high drug toxicity and increasing drug resistance mainly associated with loss-of-function mutations in the transporters involved in drug import. The introduction of new antiparasitic drugs into therapeutic use is a slow and expensive process. In contrast, specific targeting of existing drugs could represent a more rapid and cost-effective approach for neglected disease treatment, impacting through reduced systemic toxicity and circumventing resistance acquired through impaired compound uptake. We have generated nanoparticles of chitosan loaded with the trypanocidal drug pentamidine and coated by a single domain nanobody that specifically targets the surface of African trypanosomes. Once loaded into this nanocarrier, pentamidine enters trypanosomes through endocytosis instead of via classical cell surface transporters. The curative dose of pentamidine-loaded nanobody-chitosan nanoparticles was 100-fold lower than pentamidine alone in a murine model of acute African trypanosomiasis. Crucially, this new formulation displayed undiminished in vitro and in vivo activity against a trypanosome cell line resistant to pentamidine as a result of mutations in the surface transporter aquaglyceroporin 2. We conclude that this new drug delivery system increases drug efficacy and has the ability to overcome resistance to some anti-protozoal drugs.JAGS was funded by the European Union, grant FP7-HEALTH-2007-B-2.3.4-1.223048, NANOTRYP and Ministerio de Economía y Competitividad, Spain Plan Nacional de Investigación grant SAF2011- 30528. JLA was funded by Instituto de Salud Carlos III, Spain, grant FIS. 11/02571. HPdK was supported by a grant from the Medical Research Council (84733)

    An imported case of vaccine-derived poliovirus type 2, Spain in the context of the ongoing polio Public Health Emergency of International Concern, September 2021

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    The monthly retrospective search for unreported acute flaccid paralysis (AFP) cases conducted as a complementary component of the Spanish AFP surveillance system identified a case of AFP in a child admitted in Spain from Senegal during August 2021. Vaccine-derived poliovirus 2 was identified in the stool in September 2021. We present public health implications and response undertaken within the framework of the National Action Plan for Polio Eradication and the Public Health Emergency of International Concern.S

    The Interplay between Entamoeba and Enteropathogenic Bacteria Modulates Epithelial Cell Damage

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    In amoebiasis, a human disease that is a serious health problem in many developing countries, efforts have been made to identify responsible factors for the tissue damage inflicted by the parasite Entamoeba histolytica. This amoeba lives in the lumen of the colon without causing damage to the intestinal mucosa, but under unknown circumstances becomes invasive, destroying the intestinal tissue. Bacteria in the intestinal flora have been proposed as inducers of higher amoebic virulence, but the causes or mechanisms responsible for the induction are still undetermined. Mixed intestinal infections with Entamoeba histolytica and enteropathogenic bacteria, showing exacerbated manifestations of disease, are common in endemic countries. We implemented an experimental system to study amoebic virulence in the presence of pathogenic bacteria and its consequences on epithelial cells. Results showed that amoebae that ingested enteropathogenic bacteria became more virulent, causing more damage to epithelial cells. Bacteria induced release of inflammatory proteins by the epithelial cells that attracted amoebae, facilitating amoebic contact to the epithelial cells and higher damage. Our results, although a first approach to this complex problem, provide insights into amoebic infections, as interplay with other pathogens apparently influences the intestinal environment, the behavior of cells involved and the manifestations of the disease

    Optimal Pretreatment System of Flowback Water from Shale Gas Production

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    Shale gas has emerged as a potential resource to transform the global energy market. Nevertheless, gas extraction from tight shale formations is only possible after horizontal drilling and hydraulic fracturing, which generally demand large amounts of water. Part of the ejected fracturing fluid returns to the surface as flowback water, containing a variety of pollutants. For this reason, water reuse and water recycling technologies have received further interest for enhancing overall shale gas process efficiency and sustainability. Water pretreatment systems (WPSs) can play an important role for achieving this goal. This paper introduces a new optimization model for WPS simultaneous synthesis, especially developed for flowback water from shale gas production. A multistage superstructure is proposed for the optimal WPS design, including several water pretreatment alternatives. The mathematical model is formulated via generalized disjunctive programming (GDP) and solved by re-formulation as a mixed-integer nonlinear programming (MINLP) problem, to minimize the total annualized cost. Hence, the superstructure allows identifying the optimal pretreatment sequence with minimum cost, according to inlet water composition and wastewater-desired destination (i.e., water reuse as fracking fluid or recycling). Three case studies are performed to illustrate the applicability of the proposed approach under specific composition constraints. Thus, four distinct flowback water compositions are evaluated for the different target conditions. The results highlight the ability of the developed model for the cost-effective WPS synthesis, by reaching the required water compositions for each specified destination

    Stabilization and reversal of child obesity in Andalusia using objective anthropometric measures by socioeconomic status

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    Background: Childhood obesity continues to be a significant public health issue worldwide. Recent national studies in Spain show a stable picture. However, prevalence and trends differ by socio-economic status, age, and region. We present the trend in childhood excess weight prevalence, aged 8–15 years, in Andalusia from 2011-2012 to 2015–2016 by socio-economic status. Results: Overall prevalence of excess weight decreased from 42.0% in 2011–2012 to 35.4% in 2015–2016. Overweight decreased from 28.2 to 24.2% and obesity from 13.8 to 11.2%. In 2011–2012 the prevalence of excess weight in boys was 46.0%and 37.9% in girls; in 2015–2016 the difference became significant with 41% of boys with excess weight compared with 30% in girls. Conclusions: Childhood excess weight prevalence in Andalusia has decreased slightly between 2011-2012 and 2015–2016. Notably, a decrease in obesity prevalence in girls aged 8–15 years was recorded. In 2011–2012 a social gradient for excess weight prevalence across three SES indicators was observed: in 2015–2016 this gradient disappeared. Nonetheless, prevalence remains too high
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