164 research outputs found
Liquid Phase Hydrogenation of Pharmaceutical Interest Nitroarenes over Gold-Supported Alumina Nanowires Catalysts
In this work, Au nanoparticles, supported in Al2O3 nanowires (ANW) modified with
(3-aminopropyl)trimethoxysilane were synthetized, for their use as catalysts in the hydrogenation
reaction of 4-(2-fluoro-4-nitrophenyl)-morpholine and 4-(4-nitrophenyl)morpholin-3-one. ANW was
obtained by hydrothermal techniques and the metal was incorporated by the reduction of the precursor
with NaBH4 posterior to superficial modification. The catalysts were prepared at different metal
loadings and were characterized by different techniques. The characterization revealed structured
materials in the form of nanowires and a successful superficial modification. All catalysts show that
Au is in a reduced state and the shape of the nanoparticles is spherical, with high metal dispersion
and size distributions from 3.7 to 4.6 nm. The different systems supported in modified-ANW were
active and selective in the hydrogenation reaction of both substrates, finding for all catalytic systems
a selectivity of almost 100% to the aromatic amine. Catalytic data showed pseudo first-order kinetics
with respect to the substrate for all experimental conditions used in this work. The solvent plays
an important role in the activity and selectivity of the catalyst, where the highest efficiency and
operational stability was achieved when ethanol was used as the solventIndexación: Scopu
Revolutionizing fruit juice: exploring encapsulation techniques for bioactive compounds and their impact on nutrition, flavour and shelf life
Bioactive compounds in food and beverages, including fruit juices, are susceptible to degradation or oxidation during processing and storage. This vulnerability can lead to a reduction in nutritional value and overall quality of the products. The objective of this research is to explore the potential of encapsulation techniques in preserving and enhancing the nutritional value of fruit juices. The encapsulation of natural compounds, enzymes, and probiotics is seen as a promising approach to fortifying fruit juices, improving their preservation and processing of these encapsulated natural compounds as additives in food packaging. The study involves a comprehensive review of various encapsulation techniques and materials used for encapsulating bioactive compounds. It also investigates the current applications of encapsulated natural products in the preservation of food and beverages. The encapsulation of bioactive compounds has shown the potential in improving the nutritional value and functional properties of fruit juice products and foods. It has also been found to enhance the preservation and processing of these products, contributing to their overall quality and safety. Encapsulation techniques offer a promising avenue for revolutionizing the fruit juice industry by enhancing the nutritional value and shelf life of products. They also present an opportunity for the development of more functional food products. Despite the promising results, more research is needed to fully understand the mechanisms of encapsulation, determine the optimal conditions for encapsulating different ingredients, and assess the effects of encapsulation on the quality and safety of fruit juices. Future studies should focus on these areas to further advance the application of encapsulation techniques in the food and beverage industry.Javier Avendaño-Godoy is grateful to ANID/Scholarship Program/DOCTORADO
NACIONAL/2020-21202096. Danilo Escobar-Avello thanks ANID
BASAL FB210015 CENAMAD, ANID BASAL ACE210012 and ANID FONDECYT
de Postdoctorado 2023 (3230782). Víctor H. Campos-Requena thanks ANID
FONDECYT REGULAR 1190523.info:eu-repo/semantics/publishedVersio
Nanocatalizadores metálicos soportados en estructuras 0d y 1d con aplicaciones en química fina
El desafío actual en el diseño racional de catalizadores aplicados en la producción de compuestos químicos de alto valor agregado radica en la preparación de sistemas que sean capaces de operar en ciclos catalíticos consecutivos manteniendo una alta actividad y selectividad en la producción del compuesto de interés.Centro de Investigación y Desarrollo en Ciencias Aplicada
Nanocatalizadores metálicos soportados en estructuras 0d y 1d con aplicaciones en química fina
El desafío actual en el diseño racional de catalizadores aplicados en la producción de compuestos químicos de alto valor agregado radica en la preparación de sistemas que sean capaces de operar en ciclos catalíticos consecutivos manteniendo una alta actividad y selectividad en la producción del compuesto de interés.Centro de Investigación y Desarrollo en Ciencias Aplicada
Catalytic pyrolysis of used tires on noble-metal-based catalysts to obtain high-value chemicals: Reaction pathways
A systematic study on the use of noble metals (Pd, Pt, Au) supported on titanate nanotubes (NT-Ti) for selectively producing BTX and p-cymene from waste tire pyrolysis is provided here. All the materials were characterized for chemical, textural and structural properties using a range of analytical techniques. The M/NT-Ti (M: Pd, Pt, or Au) catalysts exhibit low nanoparticle sizes (1.8 Pt ≈ Au > support > non-catalyst. The Py-GC/MS suggest that the catalysts participate in the secondary reactions of dealkylation, dehydrogenation, isomerization, aromatization, and cyclization leading to a higher formation of BTX than the uncatalyzed reaction. Finally, a comprehensive reaction pathway describing the catalytic pyrolysis of WT over Pd/NT-Ti was proposed by studying the catalytic pyrolysis of individual polymers constituting the waste tires, and D,L-Limonene.Puede accederse a los datos primarios de este trabajo haciendo clic en "Documentos relacionados".Centro de Investigación y Desarrollo en Ciencias Aplicada
Hacia la valorización de neumáticos fuera de uso mediante pirólisis catalítica: efecto del catalizador sobre la distribución de productos
La disposición de los neumáticos fuera de uso (NFU) se ha convertido en una gran preocupación a nivel mundial, debido a que se requieren grandes extensiones para su almacenamiento y estos lugares se convierten en focos de incendios o de propagación de enfermedades
Dysembryoplastic Neuroepithelial Tumors: MR and CT Evaluation
PURPOSE: To evaluate dysembryoplastic neuroepithelial tumors (DNTs) on MR and CT studies and to compare DNT with other frequently encountered epileptogenic glioneuronal lesions. METH-ODS: We analyzed the MR images and CT scans of 16 patients who had complex partial epilepsy and DNT with respect to tumor location, size, CT density, MR signal intensity, mass effect, contrast enhancement, and heterogeneity, and compared these features with CT and MR findings in 51 cases of ganglioglioma and 33 cases of glioneuronal malformation. RESULTS: DNTs were located in the temporal lobe in 14 patients and in the frontal lobe in 2 patients. The cortex was involved in all cases and the subcortical white matter in 10 cases. Fifty percent of the tumors had poorly defined contours. On MR images, 14 DNTs had multiple cysts and 2 had single cysts. Contrast enhancement was observed in 6 DNTs, and mass effect was present in 9. CT scans disclosed moderately hypodense lesions in 7 patients and markedly hypodense cystic lesions in 6 patients. Two DNTs were calcified. Tumor hemorrhage with perifocal edema was observed in 1 case. Contrary to previous reports, slow but definite tumor growth was present during a 13-year period in 2 of 6 patients in whom serial CT or MR studies were obtained. CONCLUSION: A multicystic appearance on MR images is a characteristic feature of DNT and corresponds to its myxoid matrix and multinodular architecture. This feature is rare in gangliogliomas and glioneuronal malformations, and, as such, may help differentiate DNTs from these disorders
TiO2 nanorods doped with g-C3N4 – Polyethylene composite coating for self-cleaning applications
Visible-light-absorbing graphitic carbon nitride–TiO2 nanorod nanomaterials (g-C3N4@TiO2NR) were successfully immobilized using a one-step UVA-induced photocatalytic procedure on commercially obtained flexible low-density polyethylene (LDPE) films. Self-cleaning properties were evaluated in solid–liquid and solid–gas phases using malachite green as a model molecule under UV-A and visible light irradiation. For comparison purpose, LDPE films containing P25 TiO2 nanoparticles was prepared using the same synthetic strategy (P25/LDPE). Among the fabricated films, the g-C3N4@TiO2NR/LDPE films exhibited the highest photocatalytic activity both in solid–liquid and solid–gas phases after 120 min of visible light irradiation (λ > 455 nm) removing efficiently malachite green stains probably due to the attack of photoinduced reactive oxygen species (ROS) such as singlet oxygen (1O2), hydroxyl radical (•OH) and superoxide anion radical (O2−•). Furthermore, the g-C3N4@TiO2NR/LDPE films retained their visible-light-photoinduced photocatalytic properties after four reuse cycles. The g-C3N4@TiO2NR/LDPE films also exhibited significant visible-light-photoinduced hydrophilicity. The high visible-light-photoinduced photocatalytic capacity of g-C3N4@TiO2NR/LDPE films was found to be related to the textural and electronic properties, superior visible-light absorption, and surface roughness of the films.Fil: Osorio Vargas, Paula Alejandra. 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; Argentina. Universidad del Bio Bio; ChileFil: Pais Ospina, Daniel Humberto. Universidad Nacional de Tucumán. Instituto de Física del Noroeste Argentino. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Física del Noroeste Argentino; Argentina. Universidad Tecnológica de Pereira; ColombiaFil: Marín Silva, Diego Alejandro. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Pinotti, Adriana Noemi. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería; ArgentinaFil: Damonte, Laura Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Canneva, Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. YPF - Tecnología; ArgentinaFil: Donadelli, Jorge Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. YPF - Tecnología; ArgentinaFil: Pereira da Costa, Luiz. Universidad Federal del Amazonas.; BrasilFil: Pizzio, Luis Rene. 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: Torres, Cecilia C.. Universidad Andrés Bello; ChileFil: Campos, Cristian H.. Universidad de Concepción; ChileFil: Rengifo Herrera, Julian Andres. 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
Perfiles hematológicos en pacientes infectados con malaria en un área endémica del Perú
Objetivos. Evaluar la variación de los perfiles hematológicos antes, durante y después del tratamiento de pacientes infectados con malaria no complicada por Plasmodium vivax (Pv) y P. falciparum (Pf) en una población de la región Loreto. Materiales y métodos. El estudio se realizó entre 2010 y 2012, en Zungarococha (Iquitos). Los 425 participantes tuvieron tres visitas (visita 1-día 0-antes del tratamiento, visita 2-día 7-durante tratamiento, visita 3-día 28-después del tratamiento), hemograma completo, diagnóstico microscópico y molecular (PCR). Resultados. En la primera visita, se encontraron 93 (21,9%) positivos a Pv y 34 (8,0%) a Pf. Todos los positivos mostraron una reducción en los indicadores hematológicos de hematocrito, recuento de glóbulos blancos (RGB), neutrófilos abastonados y segmentados, eosinófilos y plaquetas (p<0.001) en comparación con el grupo negativo. Se encontró un porcentaje mayor de neutrófilos abastonados en Pf y de neutrófilos segmentados en Pv comparado al grupo negativo. Se observó variaciones en los perfiles hematológicos después del tratamiento para ambas especies, los neutrófilos abastonados disminuyeron, las plaquetas aumentaron, los eosinófilos se incrementaron al día 7 y decaen el día 28, el hematocrito y los neutrófilos segmentados disminuyeron al día 7 y se normalizaron
el día 28. Las diferencias entre especies en el tiempo mostraron una disminución diaria de neutrófilos abastonados en infectados con Pv que en Pf. Conclusiones. El perfil hematológico en pacientes positivos a malaria no complicada varía en el tiempo durante y después del tratamiento. Estos son indicadores de la progresión de la enfermedad y ayudan en la vigilancia terapéutica de pacientes infectados con Plasmodium
Perfiles hematológicos en pacientes infectados con malaria en un área endémica del Perú [Hematological profiles of malaria-infected patients in an endemic area of Peru]
OBJECTIVES.: To evaluate the variation of hematological profiles of patients infected with uncomplicated Plasmodium vivax (Pv) and P. falciparum (Pf) malaria before, during and after treatment in a population of the Loreto region. MATERIALS AND METHODS.: This study was conducted between 2010 and 2012, in Zungarococha (Iquitos). The 425 participants had three visits (visit 1-day 0-before treatment, visit 2-day 7-during treatment, visit 3-day 28-after treatment), complete blood count, microscopic and molecular diagnosis (PCR). RESULTS.: At the first visit, 93 (21.9%) participants were found positive for Pv and 34 (8.0%) for Pf. All positives showed a reduction in hematocrit, white blood cell count (WBC), ablated and segmented neutrophils, eosinophils and platelets (p<0.001) compared to the negative group. A higher percentage of ablated neutrophils was found in Pf and segmented neutrophils in Pv compared to the negative group. Variations in hematological profiles were observed after treatment for both species; ablated neutrophils decreased, platelets increased, eosinophils increased at day 7 and declined at day 28, hematocrit and segmented neutrophils decreased at day 7 and normalized at day 28. Interspecies differences over time showed a bigger daily decrease in ablated neutrophils in Pv-infected when compared to Pf. CONCLUSIONS.: The hematological profile in uncomplicated malaria-positive patients varies over time during and after treatment. These are indicators of disease progression and help in the therapeutic surveillance of Plasmodium-infected patients
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