285 research outputs found
The Thermal Explosion Synthesis of AlNi Monitored by Neutron Thermodiffractometry
The synthesis of AlNi from thermally activated equimolar powder mixtures of aluminium and nickel was monitored in situ and acquired diffraction patterns every 2 s or less. The analysis of diffraction patterns permitted establishment of its kinetics, which could be modeled according to an equation expressed as kt=[α/(1-α)]3/2. From 1530 to an activation energy of 9 ± 2 kJ mol−1 was estimated. Also, the crystallite size evolution on cooling was established to vary from ≈14 nm at 1530 °C to ≈28 nm at 180 °C. Finally, the reaction was found to occur through the melting of aluminium and the subsequent dissolving of nickel to form the polycrystalline single-phase product, AlNi
Galactosialidosis: Nueva mutación de novo en el gen CTSA en un paciente afecto de la forma infantil tardía
La galactosialidosis (OMIM #256540) es una enfermedad metabólica lisosomal causada por mutaciones en el gen CTSA, que codifica la proteína protectora catepsina A. La pérdida de función de dicha proteína causa, secundariamente, un déficit combinado de dos enzimas, beta-galactosidasa y neuraminidasa. Se expone el caso de un paciente que presentó manifestaciones clínicas compatibles con el subtipo infantil tardío de galactosialidosis. El análisis bioquímico mostró déficits de las dos enzimas implicadas, mientras que el estudio molecular reveló dos mutaciones: una nueva mutación nunca antes descrita, p.His475Pro (c.1424 A>C), y una mutación previamente reportada, p.Arg441Cys (c.1321C>T), localizadas en los exones 15 y 14, respectivamente. Galactosialidosis (OMIM #256540) is an autosomal recessive lysosomal storage disorder caused by mutations in the CTSA gene, which encodes the protective protein cathepsin A. The loss of function of this protein causes a secondarily deficiency of beta-galactosidase and N-acetyl-á-neuraminidase enzymes activities. We describe the clinical, biochemical and molecular analysis of a case report with a phenotype compatible with the late infantile form. The biochemical analysis reveled deficiencies of beta-galactosidase and neuraminidase activities in dried blood spot and fibroblasts and the molecular study showed two missense mutations in the CTSA gene: A previously reported mutation, p.Arg441Cys (c.1321C>T), and a novel mutation, p.His475Pro (c.1424 A>C), located in exons 14 and 15, respectively
Supergravity and the jet quenching parameter in the presence of R-charge densities
Following a recent proposal, we employ the AdS/CFT correspondence to compute
the jet quenching parameter for N=4 Yang-Mills theory at nonzero R-charge
densities. Using as dual supergravity backgrounds non-extremal rotating branes,
we find that the presence of the R-charges generically enhances the jet
quenching phenomenon. However, at fixed temperature, this enhancement might or
might not be a monotonically increasing function of the R-charge density and
depends on the number of independent angular momenta describing the solution.
We perform our analysis for the canonical as well as for the grand canonical
ensemble which give qualitatively similar results.Comment: 18 pages, 2 figures; v3: clarifying comments added, references added,
version to appear in JHE
Targeting Alzheimer’s disease with multimodal polypeptide-based nanoconjugates
Alzheimer’s disease (AD), the most prevalent form of dementia, remains incurable mainly due to our failings in the search for effective pharmacological strategies. Here, we describe the development of targeted multimodal polypeptide-based nanoconjugates as potential AD treatments. Treatment with polypeptide nanoconjugates bearing propargylamine moieties and bisdemethoxycurcumin or genistein afforded neuroprotection and displayed neurotrophic effects, as evidenced by an increase in dendritic density of pyramidal neurons in organotypic hippocampal culture. The additional conjugation of the Angiopep-2 targeting moiety enhanced nanoconjugate passage through the blood-brain barrier and modulated brain distribution with nanoconjugate accumulation in neurogenic areas, including the olfactory bulb. Nanoconjugate treatment effectively reduced neurotoxic amyloid aggregate levels and rescued impairments to olfactory memory and object recognition in APP/PS1 transgenic AD model mice. Overall, this study provides a description of a targeted multimodal polyglutamate-based nanoconjugate with neuroprotective and neurotrophic potential for AD treatment. Copyrigh
Metagenomic analysis of viruses, bacteria and protozoa in irrigation water
[EN] Viruses (e.g., noroviruses and hepatitis A and E virus), bacteria (e.g., Salmonella spp. and pathogenic Escherichia coli) and protozoa (e.g., Cryptosporidium parvum and Giardia intestinalis) are well-known contributors to food-borne illnesses linked to contaminated fresh produce. As agricultural irrigation increases the total amount of water used annually, reclaimed water is a good alternative to reduce dependency on conventional irrigation water sources. European guidelines have established acceptable concentrations of certain pathogens and/or indicators in irrigation water, depending on the irrigation system used and the irrigated crop. However, the incidences of food-borne infections are known to be underestimated and all the different pathogens contributing to these infections are not known. Next-generation sequencing (NGS) enables the determination of the viral, bacterial and protozoan populations present in a water sample, providing an opportunity to detect emerging pathogens and develop improved tools for monitoring the quality of irrigation water. This is a descriptive study of the virome, bacteriome and parasitome present in different irrigation water sources. We applied the same concentration method for all the studied samples and specific metagenomic approaches to characterize both DNA and RNA viruses, bacteria and protozoa.
In general, most of the known viral species corresponded to plant viruses and bacteriophages. Viral diversity in river water varied over the year, with higher bacteriophage prevalences during the autumn and winter. Reservoir water contained Enterobacter cloacae, an opportunistic human pathogen and an indicator of fecal contamination, as well as Naegleria australiensis and Naegleria clarki. Hepatitis E virus and Naegleria fowleri, emerging human pathogens, were detected in groundwater. Reclaimed water produced in a constructed wetland system presented a virome and bacteriome that resembled those of freshwater samples (river and reservoir water). Viral, bacterial and protozoan pathogens were occasionally detected in the different irrigation water sources included in this study, justifying the use of improved NGS techniques to get a comprehensive evaluation of microbial species and potential environmental health hazards associated to irrigation water.This work was supported through a grant funded by the Spanish Ministry of Economy and Competitiveness (MINECO) in the frame of the collaborative international consortium JPIW2013-095-C03-01, JPIW2013-095-C03-02 and JPIW2013-095-C03-03 of the Water Challenges for a Changing World Joint Programming Initiative (Water JPI) Pilot Call and partially by AGL2017-86797-C2-1-R. Silvia Bofill-Mas is a Serra-Hunter fellow at the University of Barcelona.Rusiñol, M.; Martinez-Puchol, S.; Timoneda, N.; Fernandez-Cassi, X.; Pérez-Cataluña, A.; Fernández-Bravo, A.; Moreno-Mesonero, L.... (2020). Metagenomic analysis of viruses, bacteria and protozoa in irrigation water. International Journal of Hygiene and Environmental Health. 224. https://doi.org/10.1016/j.ijheh.2019.113440S22
Understanding correlates of neighborhood aesthetic ratings: A European-based Four City comparison
Evidence of associations between nature and health behaviors and health status is mounting. However, there is a need to deconstruct “natural space” to capture the qualities of green and blue space and the various ways people experience these natural outdoor environments. These experiences influence and sustain changes in health and social behaviors such as physical activity, diet, and social connectedness. In this paper, we examine the social, cultural, and emotional factors that influence people´s perceptions of natural outdoor environments, also referred to as neighborhood aesthetics. Using a population-based sample of 2948 adults in four European cities who participated in the PHENOTYPE study, we developed a quality-based aesthetics index of nearby nature to represent our study outcome. The scale had high internal consistency (Cronbach’s alpha 0.86). We assessed its association with common measures of the natural environment (Normalized Difference Vegetation Index (NDVI)), and examined factors that may influence aesthetic ratings. Hypothesized correlates of neighborhood aesthetics including presence of and time in neighborhood nature, perceived environmental stressors and neighborhood social cohesion and attachment were generally confirmed. Contrary to our expectations, respondents born in the country of current residence rated neighborhood aesthetics lower than those born elsewhere and associations with length of residence were not consistent across countries. Interventions designed to influence social, cultural, and emotional processes could improve aesthetics ratings and potentially contribute to better health and wellbeing
ESA's PLATO mission: Development status and upcoming milestones
PLATO is the third medium class mission in ESA’s Cosmic Vision programme, with a planned launch date by end 2026. Its main objective is the detection and bulk characterisation of exoplanets down to Earth size, with emphasis on planets orbiting up to the habitable zone of bright solar-like stars. PLATO will study host stars using asteroseismology, allowing us to determine the stellar properties with high accuracy and substantially enhance our knowledge of stellar structure and evolution. Following the successful Critical Milestone Review, ESA has given green light to continue the implementation of the spacecraft and the payload, which includes the serial production of its 26 cameras. We will present the status of the satellite and the ground segment development, and report on the progress made on the PLATO Input Catalogue, the sky field selection, the ground-based follow-up observations programme, and on other activities associated with the scientific preparation. We will also give an overview of the main upcoming milestones in the mission development and in the observing strategy definition
The PLATO Mission
PLATO (PLAnetary Transits and Oscillations of stars) is ESA’s M3 mission and designed to detect and characterize extrasolar planets by high-precision, long-term photometric and asteroseismic monitoring of a large number of stars. PLATO will detect small planets around bright stars, including terrestrial planets in the habitable zone of solar-like stars. With the complement of radial velocity observation from ground, planets will be characterized for their radius, mass, and age with high accuracy. PLATO will provide us the first large-scale catalogue of well-characterized small planets up to intermediate orbital periods, relevant for a meaningful comparison to planet formation theories and to better understand planet evolution. It will make possible comparative exoplanetology to place our solar system planets in a broader context. PLATO will study host stars using asteroseismology, allowing us to determine the stellar properties with high accuracy, substantially enhancing our knowledge of stellar structure and evolution.
PLATO is scheduled for a launch date end 2026. Following the successful Critical Milestone Review, ESA has given green light for the implementation of the spacecraft and the payload, which includes the serial production of its 26 cameras. This presentation will give an overview of the PLATO science goals, of its instrument and mission profile status
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