Hydrothermal preparation of highly photoactive TiO2 nanoparticles

TiO2 nanoparticles have been prepared by amine assisted sol–gel precipitation of Ti4+ aqueous solutions and further hydrothermal treatment. The effect of different starting acidic solution (nitric, chlorhydric and acetic acids) as well as the addition of triethylamine (TEA) at different pH has been widely investigated. It has been stated that different amounts of TEA could have interesting effects upon hydrothermal treatment. Surface and morphological features significantly differ from TiO2 prepared using different synthetic route. In all cases, amine precipitated TiO2 obtained exhibit high conversion values for phenol photo-oxidation reaction, being in certain conditions higher than that exhibited by TiO2 Degussa P25. The precipitation of the acetic acidified solution leads to high surface area values and well crystallized anatase with small crystallite size. In addition, this set of catalysts show the cleanest surface after the hydrothermal treatment. The conjunction of these features would be the characteristic features responsible of the best photocatalytic activity observed

Impacto en la Usabilidad de un Sistema Web Académico desarrollado con Tecnología PHP y Framework Symfony2

En la presente investigación se realizó el análisis del uso del sistema académico web desarrollado para la "Academia Militar Tiwintsa" en la provincia Morona Santiago, el cual fue implementado utilizando la tecnología PHP con el framework Symfony2, con la finalidad de identificar el impacto del uso de estas tecnologías en la interfaz final del usuario. Para lo cual el sistema académico fue sometido a pruebas de calidad aplicando la norma ISO/IEC 9241-11, obteniendo como resultado en la métrica de efectividad un valor porcentual de 93,64 %; en la métrica de eficiencia un valor porcentual de 92,50%; y en la métrica de satisfacción un valor porcentual de 94,40%; resultados con los que se determinó que el uso de la tecnología PHP con el framework Symfony2 permite el desarrollo de un sistema intuitivo y amigable, motivando el uso diario del mismo para los diferentes procesos académicos y administrativos de la institución, pues ayuda a mejorar los tiempos de respuesta y en consecuencia la calidad de atención al client

Factores socioeconómicos que afectan la calidad de la educación universitaria bajo la modalidad en línea (Original).

The study of the factors that affect the quality of higher education in virtual modality, focuses on determining through the inductive-deductive method the economic and social factors that affect the quality of education in the environment of the student's habitat. Considering that for those who are linked to government higher education institutions, entering and staying in this modality can become a real challenge due to the lack of accessibility to ICT, housing conditions, economic resources, among other factors that in a quantitative and qualitative exploratory and explanatory character allows to identify the socioeconomic characteristics of the student population of the University of Quevedo Ecuador, delving into the analysis of delimited factors that show a contribution to academic performance through analysis of a multiple regression model.El estudio de los factores que inciden en el calidad de la educación superior en modalidad  virtual, se centra en determinar a través del método inductivo-deductivo los factores económicos y sociales que afectan la calidad de educación en el entorno del habitad del estudiante. Considerando que para quienes se vinculan a instituciones de educación superior gubernamentales, incursionar y mantenerse en esta modalidad puede convertirse en un verdadero reto debido a falta de accesibilidad a las TIC, condiciones de la vivienda, recursos económicos entre otros factores que en una investigación cuantitativa y cualitativa de carácter exploraría y explicativa permita identificar las características socioeconómicas de la población estudiantil de la Universidad de Quevedo Ecuador, profundizando en el análisis de los factores delimitados que evidencien una contribución rendimiento académico mediante análisis de un modelo de regresión múltiple.&nbsp

Venezuelan Equine Encephalitis Virus Infection of Cotton Rats

VEEV killed 2 allopatric populations of cotton rats but not a sympatric population from Florida

Cyclodextrin-mediated Crystallization of Acid β-glucosidase in Complex with Amphiphilic Bicyclic Nojirimycin Analogues

Cyclodextrin-based host-guest chemistry has been exploited to facilitate co-crystallization of recombinant human acid β-glucosidase (β-glucocerebrosidase, GlcCerase) with amphiphilic bicyclic nojirimycin analogues of the sp2-iminosugar type. Attempts to co-crystallize GlcCerase with 5-N,6-O-[N′-(n-octyl)iminomethylidene]nojirimycin (NOI-NJ) or with 5-N,6-S-[N′-(n-octyl)iminomethylidene]-6-thionojirimycin (6S-NOI-NJ), two potent inhibitors of the enzyme with promising pharmacological chaperone activity for several Gaucher disease-associated mutations, were unsuccessful probably due to the formation of aggregates that increase the heterogeneity of the sample and affect nucleation and growth of crystals. Cyclomaltoheptaose (β-cyclodextrin, βCD) efficiently captures NOI-NJ and 6S-NOI-NJ in aqueous media to form inclusion complexes in which the lipophilic tail is accommodated in the hydrophobic cavity of the cyclooligosaccharide. The dissociation constant of the complex of the amphiphilic sp2-iminosugars with βCD is two orders of magnitude higher than that of the corresponding complex with GlcCerase, allowing the efficient transfer of the inhibitor from the βCD cavity to the GlcCerase active site. Enzyme-inhibitor complexes suitable for X-ray analysis were thus grown in the presence of βCD. In contrast to what was previously observed for the complex of GlcCerase with the more basic derivative, 6-amino-6-deoxy-5-N,6-N-[N′-(n-octyl)iminomethylidene]nojirimycin (6N-NOI-NJ), the β-anomers of both NOI-NJ and 6S-NOI-NJ were seen in the active site, even though the α-anomer was exclusively detected both in aqueous solution and in the corresponding βCD:sp2-iminosugar complexes. Our results further suggest that cyclodextrin derivatives might serve as suitable delivery systems of amphiphilic glycosidase inhibitors in a biomedical context.Ministerio de Ciencia e Innovación CTQ2007-61180/PPQ, SAF2010-15670, CTQ2010-15848Junta de Andalucía P08-FQM-03711Fondo Europeo de Desarrollo Regional 03122, ISSG-CT-2007-03719

A Bicyclic 1-Deoxygalactonojirimycin Derivative as a Novel Pharmacological Chaperone for GM1 Gangliosidosis

Lysosomal β-galactosidase (β-Gal) deficiency causes a group of disorders that include neuronopathic GM1 gangliosidosis and non-neuronopathic Morquio B disease. We have previously proposed the use of small molecule ligands of β-Gal as pharmacological chaperones (PCs) for the treatment of GM1 gangliosidosis brain pathology. Although it is still under development, PC therapy has yielded promising preclinical results in several lysosomal diseases. In this study, we evaluated the effect of bicyclic 1-deoxygalactonojirimycin (DGJ) derivative of the sp2-iminosugar type, namely 5N,6S-(N′-butyliminomethylidene)-6-thio-1- deoxygalactonojirimycin (6S-NBI-DGJ), as a novel PC for human mutant β-Gal. In vitro, 6S-NBI-DGJ had the ability to inhibit the activity of human β-Gal in a competitive manner and was able to protect this enzyme from heat-induced degradation. Computational analysis supported that the rigid glycone bicyclic core of 6S-NBI-DGJ binds to the active site of the enzyme, with the aglycone N′-butyl substituent, in a precise E-orientation, located at a hydrophobic region nearby. Chaperone potential profiling indicated significant increases of enzyme activity in 24 of 88 β-Gal mutants, including four common mutations. Finally, oral administration of 6S-NBI-DGJ ameliorated the brain pathology of GM1 gangliosidosis model mice. These results suggest that 6S-NBI-DGJ is a novel PC that may be effective on a broad range of β-Gal mutants.Ministerio de Ciencia e Innovación de España. SAF2010-15670 y CTQ2010-15848Junta de Andalucía. P08-FQM-0371

Structure and activity of the Streptococcus pyogenes family GH1 6-phospho β-glycosidase, Spy1599

The group A streptococcus Streptococcus pyogenes is the causative agent of a wide spectrum of invasive infections, including necrotizing fasciitis, scarlet fever and toxic shock syndrome. In the context of its carbohydrate chemistry, it is interesting that S. pyogenes (in this work strain M1 GAS SF370) displays a spectrum of oligosaccharide-processing enzymes that are located in close proximity on the genome but that the in vivo function of these proteins remains unknown. These proteins include different sugar transporters (SPy1593 and SPy1595), both GH125 -1,6- and GH38 -1,3-mannosidases (SPy1603 and SPy1604), a GH84 -hexosaminidase (SPy1600) and a putative GH2 -galactosidase (SPy1586), as well as SPy1599, a family GH1 `putative -glucosidase'. Here, the solution of the three-dimensional structure of SPy1599 in a number of crystal forms complicated by unusual crystallographic twinning is reported. The structure is a classical (/)8-barrel, consistent with CAZy family GH1 and other members of the GH-A clan. SPy1599 has been annotated in sequence depositions as a -glucosidase (EC 3.2.1.21), but no such activity could be found; instead, three-dimensional structural overlaps with other enzymes of known function suggested that SPy1599 contains a phosphate-binding pocket in the active site and has possible 6-phospho--glycosidase activity. Subsequent kinetic analysis indeed showed that SPy1599 has 6-phospho--glucosidase (EC 3.2.1.86) activity. These data suggest that SPy1599 is involved in the intracellular degradation of 6-phosphoglycosides, which are likely to originate from import through one of the organism's many phosphoenolpyruvate phosphotransfer systems (PEP-PTSs)

El Paleozoico en el bosque Amotapes – Tahuín Perú-Ecuador

La cordillera andina presenta tres segmentos morfoestructurales definidos; como el bloque septentrional (Andes del Norte), Central (Andes Centrales) y Meridional (Patagónico). El área del presente estudio se sitúa en la zona de transición de los andes centrales a los del norte (Inflexión de Huancabamba), involucrado dentro de la región del bloque Andino del Norte. (Fig.1). Basados sobre fundamentos estratigráficos, geotectónicos y consideraciones morfoestructurales, la transición de los Andes Centrales a los Andes del Norte se pueden considerar en términos de seis dominios litotectónicos: Cuencas de Margen Continental, Bloque Amotapes-Tahuín, Cuenca Lancones, Bloque Olmos Loja, Complejo Volcánico / sed. de Zamora, Terrenos Pacifico y Melange de Peltetec. (Fig. 2). El Bloque Amotape-Tahuín comprende secuencias metamórficas correspondientes al Paleozoico Inferior y Superior constituidos de esquistos, pizarras, filitas, cuarcitas, areniscas, afectados por eventos magmáticos (Paleozoico). Se extienden desde Jubones, Sur de Zaruma-Portovelo, Puerto Viejo, Arenillas-Tahuín, El Tigre (Ecuador). Zarumilla, Tumbes (Matapalo, Angostura), Sullana (Amotapes), Paita, Illescas (Perú). Este bloque que incluye la faja metamórfica de El Oro (Ecuador); al norte está en contacto estructural con un sistema de fallas Portovelo-Arenillas y Jubones (asociado a unidades Jurasicas y Cretáceas), en el sur se presenta en contacto discordante y estructural con las secuencias volcano - sedimentaria de la Cuenca Lancones y los sedimentos marinos del Paleógeno-Neógeno. (Cuencas Talara y Sechura). El substrato Paleozoico metamórfico está cubierto en gran parte por depósitos que se desarrollaron en las Cuencas Mesozoicas y Cenozoicas, individualizadas, al Sur la Cuenca de Ñaupe, Sechura, Talara, al Norte la Cuenca Lancones – Alamor y la Cuenca Tumbes-Progreso

Zwiespältige Bilanz für Afrika : die Milleniumsziele der UN haben keine Gleichberechtigung in der Entwicklungszusammenarbeit gebracht

An increasing number of pathologies have been linked to Toll-like receptor 4 (TLR4) activation and signaling, therefore new hit and lead compounds targeting this receptor activation process are urgently needed. We report on the synthesis and biological properties of glycolipids based on glucose and trehalose scaffolds which potently inhibit TLR4 activation and signaling in vitro and in vivo. Structure–activity relationship studies on these compounds indicate that the presence of fatty ester chains in the molecule is a primary prerequisite for biological activity and point to facial amphiphilicity as a preferred architecture for TLR4 antagonism. The cationic glycolipids here presented can be considered as new lead compounds for the development of drugs targeting TLR4 activation and signaling in infectious, inflammatory, and autoimmune diseases. Interestingly, the biological activity of the best drug candidate was retained after adsorption at the surface of colloidal gold nanoparticles, broadening the options for clinical development.Italian, Ministry of University and Research (MIUR), PRIN 2010 - 11Ministerio de Economía y Competitividad AF2013-44021- R, CTQ2010 - 15848Junta de Andalucía FQM 1467Slovenian Research Agency P4-176, J1 - 417