553 research outputs found
Periodic lateralized epileptiform discharges as manifestation of pneumococcal meningoencephalitis
Periodic Lateralized Epileptiform Discharges (PLEDs) are usually seen in the context of destructive structural lesions of the cortex, more frequently in acute ischemic stroke and less common in tumours and meningoencephalitis, specially herpes simplex virus. Its origin and prognosis are uncertain but it is known that PLEDs are linked to epilectic seizures, including status epilepticus
Development of vectors and specialized Streptomyces strains for functional metagenomics
Motivation: Antimicrobial resistance (AMR) are one of the most important existing threats to public health aggravated by theoveruse of antimicrobials. It is estimated that the mortality from drug-resistance infections would increase up to 10 millions by2050. One of the major hurdles in microbial ecology is the inability to culture most of the microbial diversity present in ecosystemsunder laboratory conditions. The molecular analysis strategies used to examine the microbial community DNA, also known asthe metagenome, have been denoted as metagenomics techniques. With the use of functional metagenomics we are focus ourefforts on searching new antimicrobials. For the expression of genes from metagenomics DNA, Escherichia coli is the host mostused for function-based screening. However, the potential of Streptomyces as a surrogate host for the production of heterologousproteins has shown to be interesting for expression of proteins that are difficult to express in other bacterial host system.Methods: Basing on previous work, we are using a construction of specialized vectors with modified heterologous expressionsystem that incorporate viral components. The construction consist in the T7 RNA-polymerase gene (gene1), synthesized witha codon optimization for Streptomyces, that encodes the phage RNA-polimerase which is insensitive to many of the bacterialtermination signals. The gene1 expression is regulated by a inducible expression system based on PnitA-NitR regulatory system.To test that our system work properly, we have introduced in the cosmid for the metagenomic library construction, which isreplicative in Streptomyces, a reporter gene (xylE) whose gene product is a catechol dioxygenase which converts the colourlesssubstrate catechol to an intensely yellow oxidation product.Results: This part of the project aims to evaluate the efficience of heterologous expression measuring the catechol dioxygenaseactivity in solid and liquid media. In solid media we have seen that the Streptomyces colonies turned yellow when catechol wasapplied indicating that the expression system is working efficiently. The main objective of this project is to develop a metagenomiclibrary, with an improved heterologous expression, from DNA originating in several strains of Streptomyces in order to searchfor new antimicrobial resistance
Tuning the selectivities of Mg-Al mixed oxides for ethanol upgrading reactions through the presence of transition metals
The effect of the presence of reduced Co and Ni (chosen as representative metals because of their good activity
for dehydrogenation reactions) on the catalytic performance of basic mixed oxide (Mg-Al) for ethanol condensation
is studied in this work. This effect has been studied both in absence and in presence of hydrogen, and
considering the different steps of this complex reaction. Globally, best results were obtained with Co/MgAl,
under reducing atmosphere, at mild temperature (below 600 K). At these conditons, 1-butanol production rates
are up to eight times higher than the obtained with Mg-Al under inert atmosphere. Co has a marked activity in
the dehydrogenation step, that prevails over its less relevant activity in aldolization and hydrogenation reactions.
This result indicates the relevant role of this first reaction step. DRIFT spectroscopy analyses were carried
out to support the experimental results and to identify the role of hydrogen and metals on the oligomerization
and permanent adsorption processes, which can produce the deactivation of the catalyst.- Gobierno de España (CTQ2014-52956-C3-1-R)
- Gobierno del Principado de Asturias. Programa Severo Ochoa (PA-14-PF-BP14-105
Enhancement of the 1-butanol productivity in the ethanol condensationcatalyzed by noble metal nanoparticles supported on Mg-Al mixed oxide
The role of the addition of a noble metal (Ru and Pd) on the surface of a basic mixed oxide (MgAl) used as ethanol condensation catalyst is studied in this work. The activity trends for all the reaction steps (dehydrogenation, condensation, dehydration, and hydrogenation) were analyzed, concluding that dehydrogenation step is the rate-determining one under inert conditions whereas hydrogenations also take a relevant role under reducing conditions. Ruthenium has shown very promising 1-butanol productivities at soft conditions (15 times higher than the parent material) whereas palladium performance is limited by the lateral decarbonylation reaction, and its high hydrogenation activity is only determining at temperatures higher than 650 K
C-C Bond formation catalyzed by natural gelatin and collagen proteins
The activity of gelatin and collagen proteins towards C–C bond formation via Henry (nitroaldol) reaction between aldehydes and nitroalkanes is demonstrated for the first time. Among other variables, protein source, physical state and chemical modification influence product yield and kinetics, affording the nitroaldol products in both aqueous and organic media under mild conditions. Significantly, the scale-up of the process between 4-nitrobenzaldehyde and nitromethane is successfully achieved at 1 g scale and in good yield. A comparative kinetic study with other biocatalysts shows an increase of the first-order rate constant in the order chitosan < gelatin < bovine serum albumin (BSA) < collagen. The results of this study indicate that simple edible gelatin can promote C–C bond forming reactions under physiological conditions, which may have important implications from a metabolic perspective
Pregunte: las bibliotecas responden (Ask a librarian). Virtual reference services in Spain’s public libraries
Review and development of the Spanish virtual reference service Pregunte: las bibliotecas responden (Ask a librarian). Description of main characteristics, workflows and statistical analysis. Description of the recently established chat servic
Presentación de la línea de investigación: Medición y análisis de los impactos macroeconómicos del turismo en la economía española: 1982-2006
Con la presente comunicación queremos presentar la línea de investigación
abierta “Medición y análisis de los impactos macroeconómicos del turismo en la
economía española: 1982-2006” que estamos desarrollando desde el Departamento de
Economía Aplicada III
Evaluation of the potential of different high calorific waste fractions for the preparation of solid recovered fuels
Solid recovered fuels constitute a valuable alternative for the management of those non-hazardous waste fractions that cannot be recycled. The main purpose of this research is to assess the suitability of three different wastes from the landfill of the local waste management company (COGERSA), to be used as solid recovered fuels in a cement kiln near their facilities. The wastes analyzed were: End of life vehicles waste, packaging and bulky wastes. The study was carried out in two different periods of the year: November 2013 and April 2014. In order to characterize and classify these wastes as solid recovered fuels, they were separated into homogeneous fractions in order to determine different element components, such as plastics, cellulosic materials, packagings or textile compounds, and the elemental analysis (including chlorine content), heavy metal content and the heating value of each fraction were determined. The lower heating value of the waste fractions on wet basis varies between 10 MJ kg−1 and 42 MJ kg−1. One of the packaging wastes presents a very high chlorine content (6.3 wt.%) due to the presence of polyvinylchloride from pipe fragments, being the other wastes below the established limits. Most of the wastes analyzed meet the heavy metals restrictions, except the fine fraction of the end of life vehicles waste. In addition, none of the wastes exceed the mercury limit content, which is one of the parameters considered for the solid recovered fuels classification. A comparison among the experimental higher heating values and empirical models that predict the heating value from the elemental analysis data was carried out. Finally, from the three wastes measured, the fine fraction of the end of life vehicles waste was discarded for its use as solid recovered fuels due to the lower heating value and its high heavy metals content. From the point of view of the heating value, the end of life vehicles waste was the most suitable residue with a lower heating value of 35.89 MJ kg−1, followed by the packaging waste and the bulky waste, respectively. When mixing the wastes studied a global waste was obtained, whose classification as solid recovered fuels was NCV 1 Cl 3 Hg 3. From the empirical models used for calculating higher heating value from elemental content, Scheurer–Kestner was the model that best fit the experimental data corresponding to the wastes collected in November 2013, whereas Chang equation was the most approximate to the experimental heating values for April 2014 fractions. This difference is due to higher chlorine content of the second batch of wastes, since Chang equation is the only one that incorporates the chlorine content
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