1,283 research outputs found
In-situ Micro-Raman spectroscopic analysis of Handprints in Maltravieso Cave (Cáceres), Spain
TECHNART 2015 − Catania, April 27 - 30, 2015; http://technart2015.lns.infn.it/Peer Reviewe
Cultivo y crecimiento de dos especies de diatomeas bentónicas aisladas del Salar del Huasco (Norte de Chile, 20° S) a diferentes condiciones de temperatura, luz y nutrientes
Benthic diatoms are cultured usually under laboratory conditions to be used as a food source for other organisms, ofaquaculture interest or for biotechnological applications. Laboratory experiments demonstrate the incidence of the physicaland chemical variables on abundance and growth rates of diatoms. While macronutrients are usually selected and dosed intocommon culture mediums to meet the general requirements of a wide range of diatoms, the availability and optimizationof micronutrients are more susceptible to each organism’s particular physiological conditions. The aim of this study was tocharacterize the growth of two species of benthic diatoms isolated from the Salar de Huasco in batch cultures at differentconditions of temperature (10, 15 and 20 °C), light intensity (40, 80 and 120 ?mol m-2 s-1) and concentrations of silica (1.06x 10-4 M Na2SiO3 x 9H2O and 2.12 x 10-4 M Na2SiO3 x 9H2O) and selenium (10-8 M H2SeO3) in f/2 medium, on a lightdarkcycle of 18:6 h. Both Nitzschia epithemioides Grunow in Cleve & Grunow (1880) as Nitzschia sp. showed highermaximum cell densities (692800 ± 107704 and 649600 ± 68942 cells ml-1, respectively) and exponential growth rates(1.80±0.56 and 0.97±0.32 div. d-1, respectively) at the highest temperature (20°C). The light intensity to which the cultureswere exposed had no effect on cell density and exponential growth rate in both taxa. Regarding to nutrients, an increasein silicates concentrations on the culture medium could promote the growth of N. epithemioides and Nitzschia sp. since atendency was observed to higher cell densities (1.08 x 106 ± 84,639 and 1.32 x 106 ± 109,038 cells ml-1, respectively) andexponential growth rates (1.98 ± 0.44 and 0.95 ± 0.18 div. d-1, respectively) with respect at the normal f/2 medium and f/2medium plus selenium. Simultaneous addition of silicate and selenium to the culture medium increased the maximum celldensity of the two strains under study, but this increase was significant (p = 0.05) only for N. epithemioides and amongthe normal f/2 medium (719200 ± 116895 cells ml-1) and the f/2 medium with double the amount of silicate and selenium(1498800 ± 209599 cells ml-1). However, the exponential growth rates were not significantly different when comparedto those of the control (without the addition of silicate and selenium). In conclusion both N. epithemioides and Nitzschiasp shown an increased cell density and exponential growth rate at 20 °C. The different light intensities not significantlyinfluenced the growth of both taxa. An increase in the concentration of silicates or simultaneous increase in silicatesand selenium in the culture medium can be considered as possible strategy to increase cell density of benthic diatom N.epithemioides in batch cultures.de alimento de otros organismos de interés acuícola o para aplicaciones biotecnológicas. Experimentos de laboratoriodemuestran la incidencia de las variables físicas y químicas sobre la abundancia y tasas de crecimiento de las diatomeas.Mientras los macronutrientes están generalmente seleccionados y dosificados en los medios de cultivo más comunespara satisfacer los requerimientos generales de un amplio rango de diatomeas, la disponibilidad y optimización demicronutrientes son más susceptibles a las condiciones fisiológicas particulares de cada organismo. El objetivo de esteestudio fue caracterizar el crecimiento de dos especies de diatomeas bentónicas aisladas del Salar de Huasco en cultivostipo batch, a diferentes condiciones de temperatura (10, 15 y 20 °C), intensidad de la luz (40, 80 y 120 ?mol m-2 s-1), y
concentraciones de sílice (1.06 x 10-4 M Na2SiO3 x 9H2O y 2.12 x 10-4 M Na2SiO3 x 9H2O) y selenio (10-8 M H2SeO3)en medio f/2, a un ciclo 18:6 h luz-oscuridad. Tanto Nitzschia epithemioides Grunow in Cleve & Grunow (1880) comoNitzschia sp, exhibieron las mayores densidades celulares máximas (692800 ± 107704 y 649600 ± 68942 células mL-1,respectivamente) y tasas de crecimiento exponencial (1,80 ± 0,56 y 0,97 ± 0,32 div. d-1, respectivamente) a la temperaturamás elevada (20 °C). La intensidad de luz a la cual los cultivos fueron expuestos no afectó la densidad celular y tasa decrecimiento exponencial en ambos taxa. En cuanto a los nutrientes, un incremento en la concentración de silicatos en elmedio de cultivo, podría favorecer el crecimiento de N. epithemioides y Nitzschia sp. ya que se observó una tendenciaal aumento en la densidad celular (1,08 x 106 ± 84.639 y 1,32 x 106 ± 109.038 células mL-1, respectivamente) y tasa decrecimiento exponencial (1,98 ± 0,44 y 0,95 ± 0,18 div. d-1, respectivamente) con respecto a los medios f/2 normal y f/2más selenio. La adición simultanea de silicato y selenio al medio de cultivo aumentó las densidades celulares máximas delas dos cepas bajo estudio, pero este aumento fue significativo (p = 0,05) sólo para N. epithemioides y entre los medios decultivo f/2 normal (719200 ± 116895 células mL?1) y medio f/2 con el doble de silicato y selenio (1498800 ± 209599 célulasmL-1). Sin embargo, las tasas de crecimiento exponencial no tuvieron diferencias significativas con el control (sin adiciónde silicato y selenio). En conclusión tanto N. epithemioides y Nitzschia sp. muestran un aumento en la densidad celular yla tasa de crecimiento exponencial a 20 °C. Las diferentes intensidades de luz evaluadas no influyeron significativamenteen el crecimiento de ambos taxa. Un aumento en la concentración de silicatos o aumento simultáneo de silicatos y selenioen el medio de cultivo puede ser considerado como posible estrategia para incrementar la densidad celular de la diatomeabentónica N. epithemioides en cultivos discontinuos
Química de los cementos
En la presente comunicación se describen los resultados mas relevantes obtenidos a lo largo del tiempo en torno a algunas de las líneas de trabajo mas importantes que se desarrollan en el seno del grupo de investigación “Química del Cemento” del Instituto de Ciencias de la Construcción Eduardo Torroja (IETcc-CSIC).Edición financiada por el Ministerio de Educación y Ciencia con cargo al "Plan Nacional de I+D+I 2004-2007".Peer reviewe
Relación entre la calidad de vida en salud y la carga física en cuidadores de personas con enfermedad de Alzheimer.
Caregivers of chronic patients are themselves potential patients, who perceive a major impact on health because of their role in the care of another individual.
Objective: To describe the relationship between the quality of life in health and the physical burden in caregivers of people with Alzheimer’s disease.
Methodology: A documentary review was conducted with a qualitative approach and non-experimental design, taking into account different texts such as theses, articles, blogs And news, among others, the technique of content analysis was applied.
Results: It was found that the quality of life of caregivers’ health is clearly affected by the physical efforts they make in their caregiving, according to the amount of time invested and the stage of the pathology of the person with Alzheimer’s disease, as it progresses Pathology, increases physical dependence. The caregiver is limited only to perform activities on which the patient depends, neglecting his own health. Osteomuscular disorders and associated pains, cardiovascular pathologies, gastrointestinal disorders, disorders of the immune system, respiratory problems, tension headache, insomnia, daytime hypersomnia, nightmares, anemia, skin infections, decreased physical capacity, clumsy movement, less agile and unsafe, Feeling of dissatisfaction, feeling tired and exhausted.
Conclusion: Caregivers have an inadequate quality of life and that at some point the consequences for them can be devastating.Los cuidadores de enfermos crónicos son en sí mismo enfermos potenciales, que perciben un gran impacto en la salud a causa de su rol en a atención de otro individuo.
Objetivo: Describir la relación entre la calidad de vida en salud y la carga física en cuidadores de personas con enfermedad de Alzheimer
Métodología: Se realizó una revisión documental con enfoque cualitativo y diseño no experimental, se tuvo en cuenta diferentes textos como tesis, artículos, blogs y noticias, entre otros, se aplicó la técnica de análisis de contenido.
Resultados: Se encontró que la calidad de vida en salud de los cuidadores se ve claramente afectada por los esfuerzos físicos que realizan en su labor de cuidar, según la cantidad de tiempo invertido y el estadio de la patología de la persona con Alzheimer, a medida que avanza la patología, aumenta la dependencia física. El cuidador se ve limitado únicamente a realizar actividades de las que depende el enfermo, descuidando la propia salud. Se encontró trastornos osteomusculares y dolores asociados, patologías cardiovasculares, trastornos gastrointestinales, alteraciones del sistema inmunológico, problemas respiratorios, cefalea tensional, insomnio, hipersomnia diurna, pesadillas, anemia, infecciones cutáneas, disminución de la capacidad física, movimiento torpes, menos agiles e inseguros, sensación de insatisfacción, sensación de cansancio y agotamiento.
Conclusión: Los cuidadores tienen una inadecuada calidad de vida y que en algún momentos las consecuencias para los mismo pueden ser devastadoras
Synthesis of tri- and tetramines containing two 2,3-dihydroxypyrrolidine moieties and their inhibitory activity toward α-mannosidases
Through the reductive amination of N-[(tert-butoxy)carbonyl]-2,5-dideoxy-2,5-imino-3,4-Oisopropylidene-L-ribose with tetramethylenediamine, hexamethylenediamine, 2,7-
diaminofluorene, 4,4'-diaminodiphenylmethane and 1,4-(diaminomethyl)benzene, five
tetramines containing two (2R,3R,4S)-2-aminomethylpyrrolidine-3,4-diol moieties have been
prepared and assayed for their inhibitory activities toward 24 glycosidases. Tetramines
containing the tetramethylene or benzene-1,4-dimethylene linkers are more potent αmannosidase inhibitors than simple (2R,3R,4S)-2-aminomethylpyrrolidine-3,4-diols. Triamines
such as (2S,3R,4S)-bis(3,4-dihydroxy-pyrrolidin-2-ethyl)amine were also prepared and shown to
be better α-mannosidase inhibitors than (2S,3R,4S)-2-(2-aminoethyl)pyrrolidin-3,4-diol.The Swiss National Science Foundation (grants n° 20-63667.00 and 2100-063567.00/1)European COST (COST D13/0001/99) programOffice Fédéral de l'Education et de la Science (Bern)Dirección General de Investigación Científica y Técnica of Spain (grant n° BQU-2001-3779)SOCRATES (EPFL/Sevilla) progra
Synthesis of tri- and tetramines containing two 2,3-dihydroxypyrrolidine moieties and their inhibitory activity toward α-mannosidases
Through the reductive amination of N-[(tert-butoxy)carbonyl]-2,5-dideoxy-2, 5-imino-3,4-O-isopropylidene-L-ribose with tetramethylenediamine, hexamethylenediamine, 2,7-diaminofluorene, 4,4′-diaminodiphenylmethane and 1,4-(diaminomethyl)benzene, five tetramines containing two (2R,3R,4S)-2- aminomethylpyrrolidine-3,4-diol moieties have been prepared and assayed for their inhibitory activities toward 24 glycosidases. Tetramines containing the tetramethylene or benzene-1,4-dimethylene linkers are more potent α-mannosidase inhibitors than simple (2R,3R,4S)-2-aminomethylpyrrolidine- 3,4-diols. Triamines such as (2S,3R,4S)-bis(3,4-dihydroxy-pyrrolidin-2-ethyl) amine were also prepared and shown to be better α-mannosidase inhibitors than (2S,3R,4S)-2-(2-aminoethyl)pyrrolidin-3,4-diol
Molecular basis for glycan recognition and reaction priming of eukaryotic oligosaccharyltransferase.
Oligosaccharyltransferase (OST) is the central enzyme of N-linked protein glycosylation. It catalyzes the transfer of a pre-assembled glycan, GlcNAc2Man9Glc3, from a dolichyl-pyrophosphate donor to acceptor sites in secretory proteins in the lumen of the endoplasmic reticulum. Precise recognition of the fully assembled glycan by OST is essential for the subsequent quality control steps of glycoprotein biosynthesis. However, the molecular basis of the OST-donor glycan interaction is unknown. Here we present cryo-EM structures of S. cerevisiae OST in distinct functional states. Our findings reveal that the terminal glucoses (Glc3) of a chemo-enzymatically generated donor glycan analog bind to a pocket formed by the non-catalytic subunits WBP1 and OST2. We further find that binding either donor or acceptor substrate leads to distinct primed states of OST, where subsequent binding of the other substrate triggers conformational changes required for catalysis. This alternate priming allows OST to efficiently process closely spaced N-glycosylation sites
Population-Based Study of New Mutations Causing Sandhoff Disease in Argentina
2pSandhoff Disease (SD) is a lysosomal storage disorder caused by mutations in the HEXB gene. A high incidence
of SD has been described in an Argentine region called ‘‘Valle de Traslasierra.’’ Mutations c.445þ1G>A and p.S261Cfs12X
were found in 98.7% and 1.3% of mutant alleles, respectively. In previous population-based studies, the carrier frequency has
been estimated to be 1 in 16 to 29, all heterozygous with c.445þ1G>A. Recently, we detected new mutations in 5 Argentinian patients: c.1082þ5G>A, c.1242þ1G>A, c.1451G>A (p.Gly484Glu), c.1597C>T (p.Arg533Cys) and c.1601G>A (p.Cys534Tyr).Fil: Mugnaini, Julia. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Centro de Estudio de las Metabolopatías Congénitas (CEMECO). Hospital de Niños. Cátedra de Clínica Pediátrica; Argentina.Fil: Dardis, Andrea. Hospital Universitario ‘‘Santa Maria del la Misericordia’’. Centro Coordinador Regional de Enfermedades Raras, Udine; Italia.Fil: Dodelson de Kremer, Raquel. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Hospital de Niños. Centro de Estudio de las Metabolopatías Congénitas (CEMECO). Cátedra de Clínica Pediátrica; ArgentinaFil: Oller Ramírez, Ana María. Universidad Nacional de Córdoba. Facultad de Ciencias Medicas. Hospital de Niños. Centro de Estudio de las Metabolopatías Congénitas (CEMECO). Cátedra de Clínica Pediátrica; Argentina.Fil: Azar, Nydia Beatriz. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Centro de Estudio de las Metabolopatías Congénitas (CEMECO). Hospital de Niños. Cátedra de Clínica Pediátrica; ArgentinaFil: Becerra, Adriana. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Centro de Estudio de las Metabolopatías Congénitas (CEMECO). Hospital de Niños. Cátedra de Clínica Pediátrica; Argentina.Fil; Zampieri, S. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Centro de Estudio de las Metabolopatías Congénitas (CEMECO). Hospital de Niños. Cátedra de Clínica Pediátrica; Argentina.Fil: Guelbert, Norberto. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Centro de Estudio de las Metabolopatías Congénitas (CEMECO). Hospital de Niños. Cátedra de Clínica Pediátrica; Argentina.Bioquímica y Biología Molecula
Synergetic improvement of stability and conductivity of hybrid composites formed by PEDOT:PSS and SnO nanoparticles
In this work, layered hybrid composites formed by tin oxide (SnO) nanoparticles synthesized by hydrolysis and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) have been analyzed. Prior to the composite study, both SnO and PEDOT:PSS counterparts were characterized by diverse techniques, such as X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), photoluminescence (PL), atomic force microscopy (AFM), optical absorption and Hall effect measurements. Special attention was given to the study of the stability of the polymer under laser illumination, as well as the analysis of the SnO to SnO_2 oxidation assisted by laser irradiation, for which different laser sources and neutral filters were employed. Synergetic effects were observed in the hybrid composite, as the addition of SnO nanoparticles improves the stability and electrical conductivity of the polymer, while the polymeric matrix in which the nanoparticles are embedded hinders formation of SnO_2. Finally, the Si passivation behavior of the hybrid composites was studied
Origin, distribution, and potential risk factors associated with influenza A virus in swine in two production systems in Guatemala
Background: Guatemala is the country with the largest swine production in Central America; however, evidence of influenza A virus (IAV) in pigs has not been clearly delineated.
Objectives: In this study, we analyzed the presence and spatial distribution of IAV in commercial and backyard swine populations.
Methods: Samples from two nationwide surveys conducted in 2010 and 2011 were tested using virological (rRT-PCR and virus isolation) and serological (ELISA and hemagglutination inhibition) assays to detect IAV.
Results: Influenza A virus was detected in 15.7% of the sampled pigs (30.6% of herds) in 2010 and in 11.7% (24.2% of herds) in 2011. The percentage of seropositive pigs was 10.6% (16.1% of herds) and 1.4% (3.1% of herds) for each year, respectively. Three pandemic H1N1 and one seasonal human-like H3N2 viruses were isolated. Antibodies against viruses from different genetic clusters were detected. No reassortant strains with swine viruses were detected. The H3N2 virus was closely related to human viruses that circulated in Central America in 2010, distinct to the most recent human seasonal vaccine lineages. Spatial clusters of rRT-PCR positive herds were detected each year by scan statistics.
Conclusions: Our results demonstrate circulation of IAV throughout Guatemala and identify commercial farms, animal health status, and age as potential risk factors associated with IAV infection and exposure. Detection of human-origin viruses in pigs suggests a role for humans in the molecular epidemiology of IAV in swine in Guatemala and evidences gaps in local animal and human surveillance
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