CFD modeling of a road tunnel with multiple sources of Co. case of study: boqueron-I tunnel

This work aims to the modeling of CO transport in one section considered critical of the Boqueron I tunnel, located on the outskirts of Caracas, the capital city of Venezuela, with a scenario where vehicles are stopped by an interruption of traffic. This scenario considers a relationship between the number of large-sized vehicles (buses or trucks) and small-sized vehicles (passenger cars) reported by transit statistics and also, it considers the semi-transverse ventilation system in the tunnel. It is explored the influence of the ventilation on the flow patterns and its relationship to the regions with the highest CO concentration. The finite-volume based finite element method is used for the discretization of the computational domain and the integration of the governing equations. The transient 3D-incompressible Navier-Stokes, energy, mass and species conservation equations, along with the k-e turbulence equations, were discretized, using higher-order numerical schemes in space. The numerical simulation is performed using a fully implicit coupled treatment of the set of resulting discrete transport equation

Ternary Hydrotalcites in the Multicomponent Synthesis of 4H-Pyrans

Lamellar double hydroxides (LDH) with double divalent cations were synthesized by the co-precipitation method and studied in the multicomponent synthesis of 4H-pyrans. The solids obtained were characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), N2 adsorption isotherms, and thermogravimetric analysis (TGA). The XRD patterns confirmed the formation of LDHs in which the incorporation of Ni2+ or Co2+ improves their crystalline and textural properties. The results of catalytic activity showed that the synthesis of 4H-pyrans is favored in solvent-free conditions with the LDH–Ni catalyst, avoiding calcination processes. In addition, it was found that hydrotalcite with double divalent cations can conduct this reaction through multicomponent synthesis or by the Michael addition reaction, which can be performed by different types of basicity that depend on the composition of another divalent cation in the brucite layer or a calcination process

Caffeine photocatalytic degradation using composites of NiO/TiO2–F and CuO/TiO2–F under UV irradiation

The interest in the removal of emerging contaminants has increased in the last decade. Photocatalytic degradation using p-n heterojunctions could effectively provide the degradation of these type of substances that are persistent in the environment. In this work, the synthesis, characterization, and photocatalytic evaluation of TiO2–F as well as CuO/TiO2–F and NiO/TiO2–F composite materials were studied in the photo-assisted degradation of caffeine using UV radiation. The fluorination of titanium dioxide induced changes in some physicochemical properties of the materials, which contributed to a decrease in surface area and bandgap energy as well as an increase in crystallite size as compared to pristine TiO2. ≡Ti–F species were evidenced to be formed, which could favor charge separation processes. A highest segregation of CuO species in comparison with NiO on the surface of TiO2–F could be formed, which could increase defect sites and decrease the band gap. The formation of a heterojunction between the semiconductors was evidenced, responsible for the observed improvements in photocatalytic properties of the composite materials. The photocatalytic tests evidenced an important degradation of caffeine; however, mineralization was incomplete. The stability of the composite materials and their potential use in the photocatalytic treatment of caffeine was evaluated by reuse tests

Whey as an Alternative Nutrient Medium for Growth of Sporosarcina pasteurii and Its Effect on CaCO3 Polymorphism and Fly Ash Bioconsolidation

Whey in large quantities can cause environmental problems when discarded, because it reduces dissolved oxygen and aquatic life. Nonetheless, it could be used as an easily available and economical alternative to reduce culture medium costs in microbially induced calcium carbonate precipitation (MICP). In this work, a native Sporosarcina pasteurii was isolated and then cultured by using different proportions of whey (W) in nutrient broth (NB). The solids were characterized by XRD, FT-IR, TGA, and SEM. The potential applications in bioconsolidation were also studied. Whey concentration was directly related to CaCO3 production. Higher whey concentrations reduced calcium carbonate purity to nearly 80%. All experiments showed calcite and vaterite fractions, where a whey increment in the media increased calcite content and decreased vaterite content, causing a decrease in crystal size. MICP improved compressive strength (CS) in sand and fly ash. The best CS results were obtained by fly ash treated with 25 W-75 NB (37.2 kPa) and sand with 75 W-25 NB (32.1 kPa). Whey changed crystal polymorphism in biogenic CaCO3 production. Material bioconsolidation depends on the CaCO3 polymorph, thus fly ash was effectively bioconsolidated by crystallization of vaterite and sand by crystallization of calcite

EPIC247098361b: a transiting warm Saturn on an eccentric P=11.2P=11.2 days orbit around a V=9.9V=9.9 star

We report the discovery of EPIC247098361b using photometric data of the Kepler K2 satellite coupled with ground-based spectroscopic observations. EPIC247098361b has a mass of M$_{P}=0.397\pm 0.037$ M$_J$, a radius of R$_{P}=1.00 \pm 0.020$ R$_J$, and a moderately low equilibrium temperature of $T_{eq}=1030 \pm 15$ K due to its relatively large star-planet separation of $a=0.1036$ AU. EPIC247098361b orbits its bright ($V=9.9$) late F-type host star in an eccentric orbit ($e=0.258 \pm 0.025$) every 11.2 days, and is one of only four well characterized warm Jupiters having hosts stars brighter than $V=10$. We estimate a heavy element content of 20 $\pm$ 7 M$_{\oplus}$ for EPIC247098361b, which is consistent with standard models of giant planet formation. The bright host star of EPIC247098361b makes this system a well suited target for detailed follow-up observations that will aid in the study of the atmospheres and orbital evolution of giant planets at moderate separations from their host stars.Comment: 11 pages, 10 figures, submitted to MNRA

Acetylated nanocellulose for single-component bioinks and cell proliferation on 3D-printed scaffolds

Nanocellulose has been demonstrated as a suitable material for cell culturing, given its similarity to extracellular matrices. Taking advantage of the shear thinning behavior, nanocellulose suits three-dimensional (3D) printing into scaffolds that support cell attachment and proliferation. Here, we propose aqueous suspensions of acetylated nanocellulose of a low degree of substitution for direct ink writing (DM). This benefits from the heterogeneous acetylation of precursor cellulosic fibers, which eases their deconstruction and confers the characteristics required for extrusion in DIW. Accordingly, the morphology of related 3D printed architectures and their performance during drying and rewetting as well as interactions with living cells are compared with those produced from typical unmodified and TEMPO-oxidized nanocelluloses. We find that a significantly lower concentration of acetylated nanofibrils is needed to obtain bioinks of similar performance, affording more porous structures. Together with their high surface charge and axial aspect, acetylated nanocellulose produces dimensionally stable monolithic scaffolds that support drying and rewetting, required for packaging and sterilization. Considering their potential uses in cardiac devices, we discuss the interactions of the scaffolds with cardiac myoblast cells. Attachment, proliferation, and viability for 21 days are demonstrated. Overall, the performance of acetylated nanocellulose bioinks opens the possibility for reliable and scaleup fabrication of scaffolds appropriate for studies on cellular processes and for tissue engineering.Peer reviewe

Crisis psicógenas no epilépticas en psiquiatría infantil

ResumenLas crisis psicógenas no epilépticas son episodios paroxÍsticos de alteración en los movimientos, sensaciones o experiencia que puede imitar una crisis convulsiva, fuertemente asociadas a sufrimiento emocional y no asociado a descargas eléctricas cerebralesanormales. Esta entidad puede ocurrir a cualquier edad y predomina en el género femenino. Se considera una expresión involuntaria asocáada a dáfáculÍades emocáonales. bs un dáagnósÍáco ámprecásoI pero de gran utilidad. Se puede manifestar de múltiples formas como movimientos rotatorios de cabeza o de pelvis, pataleo, crisis cambiantes y son fácilmente sugestionables. En niños los estudios muestran gran comorbilidad con entidades como depresión, ansiedad, epilepsia, rechazo escolar, trastorno de pánico, entre otras. El diagnóstico es clÍnico, donde la video telemetrÍa es el examen más importante. Se describe la experiencia local con 12 pacientes, predominio en mujeres (84%) entre 7 y 17 años, que consultaronprincipalmente por convulsiones (83%). La ansiedad fue la principal alteración encontrada (58%), seguido por depresión en (41%), disfunción familiar (25%). El 66% de pacientes tuvieron Epilepsia focal y el 50% de casos presentó estado epiléptico psicógeno. Las medicaciones más utilizadas en neuropediatrÍa fueron carbamazepánaI ácádo valpróáco óI por psáquáaÍrÍaI fluoxeÍána. ias pseudocrásás se convierten en eventos de gran importancia porque evidencian una serie de alteraciones emocionales que explican los sÍntomas similares a una convulsión.[Vásquez R, Silvestre JJ, Escobar M. Crisis psicógenas no epilépticas en psiquiatrÍa infantil. MedUNAB 2006; 9:230-235]Palabras Clave: Pseudocrisis, crisis psicógenas, epilepsia, ansiedad, depresión

Ternary hydrotalcites in the multicomponent synthesis of 4H-pyrans

Lamellar double hydroxides (LDH) with double divalent cations were synthesized by the co-precipitation method and studied in the multicomponent synthesis of 4H-pyrans. The solids obtained were characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), N2 adsorption isotherms, and thermogravimetric analysis (TGA). The XRD patterns confirmed the formation of LDHs in which the incorporation of Ni2+ or Co2+ improves their crystalline and textural properties. The results of catalytic activity showed that the synthesis of 4H-pyrans is favored in solvent-free conditions with the LDH–Ni catalyst, avoiding calcination processes. In addition, it was found that hydrotalcite with double divalent cations can conduct this reaction through multicomponent synthesis or by the Michael addition reaction, which can be performed by different types of basicity that depend on the composition of another divalent cation in the brucite layer or a calcination process.Fil: Nope Vargas, Eliana Rocio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Sathicq, Angel Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Martínez, José J.. Universidad Pedagógica y Tecnológica de Colombia; ColombiaFil: Rojas, Hugo A.. Universidad Pedagógica y Tecnológica de Colombia; ColombiaFil: Luque, Rafael. Universidad de Córdoba; EspañaFil: Romanelli, Gustavo Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; Argentin

Structural analyses to identify selective inhibitors of glyceraldehyde 3-phosphate dehydrogenase-S, a sperm-specific glycolytic enzyme

Detailed structural comparisons of sperm-specific glyceraldehyde 3-phosphate dehydrogenase, spermatogenic (GAPDHS) and the somatic glyceraldehyde 3-phosphate dehydrogenase (GAPDH) isozyme should facilitate the identification of selective GAPDHS inhibitors for contraceptive development

Impaired Virulence and In Vivo Fitness of Colistin-Resistant Acinetobacter baumannii

4 páginas, 2 figuras. Presentado en parte: 20 º Congreso Europeo de Microbiología Clínica y Enfermedades Infecciosas, Resumen 1389, Viena, Austria, 10-13 de abril de 2010.Acinetobacter baumannii (American Type Culture Collection strain 19606) acquires mutations in the pmrB gene during the in vitro development of resistance to colistin. The colistin-resistant strain has lower affinity for colistin, reduced in vivo fitness (competition index, .016), and decreased virulence, both in terms of mortality (0% lethal dose, 6.9 vs 4.9 log colony-forming units) and survival in a mouse model of peritoneal sepsis. These results may explain the low incidence and dissemination of colistin resistance in A. baumannii in clinical settings.This work was supported by the European Development Regional Fund “A way to achieve Europe” (ERDF); the Spanish Network for the Research in Infectious Diseases (REIPI RD06/0008), Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación, Spain; and the Autonomous government of Madrid (COMBACT S-BIO-0260/2006, L.R.).Peer reviewe