1,057 research outputs found
Chemical and Enzymatic Approaches to Carbohydrate-Derived Spiroketals: Di-D-Fructose Dianhydrides (DFAs)
Biofilm formation in spent nuclear fuel pools and bioremediation of radioactive water
Microbiological studies of spent nuclear fuel pools at the Cofrentes Nuclear Power Plant (Valencia, Spain) were initiated to determine the microbial populations in the pools’ water. Biofilm formation at the nuclear power plant facilities and the potential use of those microbial populations in the bioremediation of radioactive water were also studied. Biofilm formation was analyzed by immersing different austenitic stainless steel coupons (UNS S30400, UNS S30466, UNS S31600), as well as balls of stainless steel (UNS S44200) and titanium (99.9%) in a spent nuclear fuel pool (under static and dynamic conditions) for 34 months. Epifluorescence microscopy and scanning electron microscopy revealed that biofilm formed on the samples, in spite of the radioactive and oligotrophic conditions of the water. Based on standard culture methods and sequencing of 16S rDNA fragments, 57 bacteria belonging to α-, β-, and γ-Proteobacteria, Firmicutes and Actinobacteridae were identified in the biofilms. The radioactivity of the biofilm was measured using γ-ray spectrometry, which revealed that biofilms were able to retain radionuclides, especially 60Co. Using metallic materials to decontaminate radioactive water could become a new approach for bioremediation. [Int Microbiol 2005 8(3):223-230
Stereoselective Synthesis of Nojirimycin α-C-Glycosides from a Bicyclic Acyliminium Intermediate: A Convenient Entry to N,C-Biantennary Glycomimetics
A simple and efficient method for the stereoselective synthesis of nojirimycin α-C-glycoside derivatives has been developed using a bicyclic carbamate-type sp2-iminosugar, whose preparation on a gram scale has been optimized, as the starting material. sp2-iminosugar O-glycosides or anomeric esters serve as excellent precursors of acyliminium cations, which can add nucleophiles, including C-nucleophiles. The stereochemical outcome of the reaction is governed by stereoelectronic effects, affording the target α-anomer with total stereoselectivity. Thus, the judicious combination of C-allylation, carbamate hydrolysis, cross-metathesis, and hydrogenation reactions provides a very convenient entry to iminosugar α-C-glycosides, which have been transformed into N,C-biantennary derivatives by reductive amination or thiourea-forming reactions. The thiourea adducts undergo intramolecular cyclization to bicyclic iminooxazolidine iminosugar α-C-glycosides upon acid treatment, broadening the opportunities for molecular diversity. A preliminary evaluation against a panel of commercial glycosidases validates the approach for finely tuning the inhibitory profile of glycomimetics.España MCIN/AEI/10.13039/ 501100011033Unión Europea ERDF A way of making Europe” (grant nos. PID2019-105858RB-I00 and RTI2018-097609-B-C21)Junta de Andalucía (Grant number P20_00166
Los arrabales de la Córdoba musulmana. De las fuentes escritas a la realidad arqueológica
We present in this report our particular visión about the knowledge situation of islamic Cordoba 's suburbs, departing from a little historiographic analysis and finishing, after explaining the facts we have nomaday thanks to the archeology, with a criticism trought of the present view.Presentamos en este artículo nuestra particular visión del estado de la cuestión sobre los arrabales de la Córdoba musulmana, partiendo de un sucinto análisis historiográfico y concluyendo, tras exponer los datos con que contamos en la actualidad gracias al rigor arqueológico, con una reflexión crítica del panorama actual.Comunicación presentada a: Jornadas Cordobesas de Arqueología Andaluza. Arqueología de Al Andalus: Los palacios islámicos. XI. 2001. Córdob
Influence of assessment in the teaching-learning process in the higher education
The new European Higher Education Area (EHEA) involves a change in the way of understanding learning and the teacher?s work. In this field, assessment is a very important aspect in education. It influences determinedly in the process of helping and encouraging the students to learn and understand their progresses in learning. This paper shows, from the results obtained in the subject "Concrete as a Structural Material", of fourth grade in Building Degree, the factors which affect the teaching-learning process through assessmen
Analysis of the Influence of Terrain Orientation on the Design of PV Facilities with Single-Axis Trackers
This paper investigates how to optimally orient the photovoltaic solar trackers of an axis parallel to the terrain, applying the sky model of Hay–Davies. This problem has been widely studied. However, the number of studies that consider the orientation (inclination and azimuth of the terrain) is very limited. This paper provides an examination of incident solar irradiance that can be extended to terrain with variable orientation and in consideration of different azimuths of the axis of rotation. Furthermore, a case study of the south of Spain is provided, considering different inclination and orientation terrain values. The results obtained in this study indicate, as a novelty, that for lands that are not south facing, the rotation axis azimuth of solar trackers should be different from zero and adjusted to the same direction as the land azimuth in order to maximize energy production. Annual energy production is sensitive to changes in the rotation axis azimuths of solar trackers (an influence of around 3% of annual energy production)
Minería y metalurgia durante la I Edad del Hierro. Procesos de cambio en el sur de Cataluña
El objetivo de este artículo es ofrecer un breve resumen de la investigación acerca de la minería y la metalurgia en la 1ª Edad
del Hierro del sur de Catalunya, basado en el reciente trabajo de campo y los estudios analíticos en tres áreas: el valle bajo del río Siurana, la Terra Alta-Algars-Matarranya y el curso bajo del Sénia.Se discuten los diferentes procesos de cambio social.The aim of this paper is to present a summary of research concerning mining and metallurgy in the Early Iron Age of southern Catalonia, on the basis of recent fieldwork and analytical studies in three areas: the lower valley of the River Siurana; La Terra Alta-Algars-Matarranya; and the lower course of the River Sénia. Different processes of social change are discussed.Plan Nacional de I+D+I
2004-2007 proyectos ref. HUM 2004-04861-C02 y C03), y HUM2004-03121/HIS
Capsid amino acids at positions 247 and 270 are involved in the virulence of betanodaviruses to European sea bass
European sea bass (Dicentrarchus labrax) is severely afected by nervous necrosis disease, caused by
nervous necrosis virus (NNV). Two out of the four genotypes of this virus (red-spotted grouper nervous
necrosis virus, RGNNV; and striped jack nervous necrosis virus, SJNNV) have been detected in sea bass,
although showing diferent levels of virulence to this fsh species. Thus, sea bass is highly susceptible
to RGNNV, whereas outbreaks caused by SJNNV have not been reported in this fsh species. The role
of the capsid protein (Cp) amino acids 247 and 270 in the virulence of a RGNNV isolate to sea bass has
been evaluated by the generation of recombinant RGNNV viruses harbouring SJNNV-type amino acids
in the above mentioned positions (Mut247Dl965, Mut270Dl965 and Mut247+270Dl965). Viral in vitro
and in vivo replication, virus virulence and fsh immune response triggered by these viruses have been
analysed. Mutated viruses replicated on E-11 cells, although showing some diferences compared to the
wild type virus, suggesting that the mutations can afect the viral cell recognition and entry. In vivo, fsh
mortality caused by mutated viruses was 75% lower, and viral replication in sea bass brain was altered
compared to non-mutated virus. Regarding sea bass immune response, mutated viruses triggered a
lower induction of IFN I system and infammatory response-related genes. Furthermore, mutations
caused changes in viral serological properties (especially the mutation in amino acid 270), inducing
higher seroconversion and changing antigen recognitionThis study has been supported by the projects AGL2017-84644-R (MINECO/AEI/FEDER, UE) and AGL2014-53532-C (MINECO/FEDER). The authors thank Juan Gémez for helping in lab work. P.M. was supported by a Fellowship of the Ministerio de Educación, Spanish Government, and a contract of the project AGL2017-84644-R (MINECO/AEI/FEDER, UE). R.L.-R. was supported by the project P12-RNM-2261 (Junta de Andalucia)S
sp2-Iminosugars targeting human lysosomal β-hexosaminidase as pharmacological chaperone candidates for late-onset Tay-Sachs disease
The late-onset form of Tay-Sachs disease displays when the activity levels of human β-hexosaminidase A (HexA) fall below 10% of normal, due to mutations that destabilise the native folded form of the enzyme and impair its trafficking to the lysosome. Competitive inhibitors of HexA can rescue disease-causative mutant HexA, bearing potential as pharmacological chaperones, but often also inhibit the enzyme O-glucosaminidase (GlcNAcase; OGA), a serious drawback for translation into the clinic. We have designed sp2-iminosugar glycomimetics related to GalNAc that feature a neutral piperidine-derived thiourea or a basic piperidine-thiazolidine bicyclic core and behave as selective nanomolar competitive inhibitors of human Hex A at pH 7 with a ten-fold lower inhibitory potency at pH 5, a good indication for pharmacological chaperoning. They increased the levels of lysosomal HexA activity in Tay-Sachs patient fibroblasts having the G269S mutation, the highest prevalent in late-onset Tay-Sachs disease.Ministerio de Ciencia e Innovación 10.13039/50110001103Fondo Europeo de Desarrollo Regional PID2019-105858RB-I00, RTI2018-097609-B-C21Junta de Andalucía P20_00166Canadian Institutes of Health Research MOP-123341Natural Sciences and Engineering Research Council of Canada RGPIN-06466Japan Society for the Promotion of Science 17K10051Universidad de Sevilla BES-2017–079676, FPU17/0314
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