Article
Nanoscience & Nanotechnology
S. Kurajica, I. K. Ivkovic, G. Drazic, V Shvalya, M. Duplancic, G. Matijasic, U. Cvelbar, K. Muzina
Summary: Manganese-doped ceria nanoparticles were synthesized and thermally treated, resulting in improved catalytic activity for toluene oxidation. The presence of manganese in the ceria lattice structure altered the properties of the nanoparticles, leading to an increase in oxygen adsorption that promoted surface reactions.
Article
Materials Science, Multidisciplinary
Akihiro Ishii, Hibiki Ishijima, Kosei Kobayashi, Itaru Oikawa, Hitoshi Takamura
Summary: The key element for low-temperature sintering of Sm-doped CeO2 was found to be aluminum, which was spontaneously introduced through a chemical reaction with mixed lithium and alumina crucible. Zirconium was also introduced through ball-mill processing. Both aluminum and zirconium play an important role in reducing the melting point and achieving low-temperature sintering.
Article
Chemistry, Multidisciplinary
Ivana Katarina Ivkovic, Stanislav Kurajica, Marina Duplancic, Fabio Faraguna, Tea Grbesic
Summary: Manganese doped nanosized ceria samples were prepared using mechanochemical synthesis and characterized using various techniques. Different synthesis conditions were tested, and the product was found to contain cerium carbonate, cerium chloride, and an amorphous phase. The introduction of manganese led to changes in the lattice constant and bandgap of ceria, and the doped samples showed promising catalytic activity.
Article
Chemistry, Multidisciplinary
Elisabeth Hornberger, Malte Klingenhof, Shlomi Polani, Paul Paciok, Attila Kormanyos, Raphael Chattot, Katherine E. MacArthur, Xingli Wang, Lujin Pan, Jakub Drnec, Serhiy Cherevko, Marc Heggen, Rafal E. Dunin-Borkowski, Peter Strasser
Summary: Recently proposed bimetallic octahedral Pt-Ni electrocatalysts for the ORR suffer from particle instabilities. In this work, a novel quaternary octahedral PtNi(RhMo) catalyst was synthesized, showing high ORR performance and shape integrity. The addition of Rh and Mo as surface dopants suppresses detrimental Pt diffusion and offers potential for catalyst system improvement.
Article
Chemistry, Inorganic & Nuclear
Soumitra Sulekar, Mehrad Mehr, Ji Hyun Kim, Juan Claudio Nino
Summary: Rare-earth doped ceria materials are widely used in intermediate temperature solid oxide fuel cells due to their enhanced ionic conductivity. Trivalent acceptor dopants such as gadolinium tend to segregate at grain boundaries, resulting in the formation of ionically resistive blocking grain boundaries. By improving the sintering cycle, the grain boundary resistance can be significantly reduced, leading to improved ionic conductivity.
Article
Materials Science, Ceramics
S. Kurajica, I. K. Ivkovic, K. Muzina, V Mandic, I Panzic, G. Matijasic, E. E. Alic
Summary: Pure and manganese-doped ceria nanopowders were prepared using the sol-gel method, and their properties were characterized. The study found that manganese inhibits the grain growth rate of ceria, and doped samples have smaller crystallite sizes and greater specific surface areas. The catalytic efficiency of ceria was improved by doping with manganese, as demonstrated in the toluene oxidation test.
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
(2022)
Article
Materials Science, Ceramics
Henry Gandelman, Andre L. da Silva, Bruno Ramos, Douglas Gouvea
Summary: This study investigated the effect of Sb doping on the properties of TiO2 nanoparticles, finding that Sb interfacial segregation at both surface and grain boundaries can increase the specific surface areas, change the crystallite sizes, affect CO2 adsorption, and enhance photocatalytic activity, with a 53% increase in activity for 0.05 mol% Sb-doped TiO2 compared to undoped TiO2.
CERAMICS INTERNATIONAL
(2021)
Article
Biochemistry & Molecular Biology
Valentina A. A. Petrova, Iosif V. V. Gofman, Natallia V. V. Dubashynskaya, Alexey S. S. Golovkin, Alexander I. I. Mishanin, Elena M. M. Ivan'kova, Dmitry P. P. Romanov, Albert K. K. Khripunov, Elena N. N. Vlasova, Alexandra V. V. Migunova, Alexander E. E. Baranchikov, Vladimir K. K. Ivanov, Alexander V. V. Yakimansky, Yury A. A. Skorik
Summary: New composite films were prepared by incorporating bacterial cellulose nanofibers and cerium oxide nanoparticles into chitosan matrices. The amount of nanofillers affected the structure and properties of the composites, including film stiffness and strength. Increasing the concentration of nanoceria improved the biocompatibility and adhesion of the films to mesenchymal stem cells. These nanocomposite films exhibit favorable properties for use as matrix materials in cell culture and wound dressings.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Physical
Ke Gao, Xianglei Liu, Qi Wang, Zhixing Jiang, Cheng Tian, Nan Sun, Yimin Xuan
Summary: Solar thermochemical CO2 splitting using Ce- and Al-doped SrMnO3 perovskites is proposed for efficient solar fuel production. The doped material shows an ultrahigh CO yield and improved CO2 splitting kinetics compared to undoped SrMnO3. It also exhibits excellent stability over multiple cycles. This work provides a new path for high-performance solar thermochemical CO2 splitting.
SUSTAINABLE ENERGY & FUELS
(2023)
Article
Chemistry, Physical
Ilan Riess
Summary: The dependence of [Pr3+]s (Pr3+ concentration in the surface monomolecular layer of Pr0.1Ce0.9O2-delta) on oxygen pressure, P(O-2), is analyzed in this study. The surface is negatively charged due to excess Pr3+ ions, while the bulk is positively charged due to excess oxygen vacancies. The [Pr3+]s - P(O-2) relations are derived for the reduction of Pr4+ to Pr3+. Under low P(O-2), [Pr3+]s reaches its maximum concentration. At high P(O-2), [Pr3+]s is inversely proportional to P(O-2)(-1/8), which is different from the relation in the neutral bulk. Full evaluation of the space charge distribution in the bulk is not necessary for calculating the [Pr3+]s - P(O-2) relations.
SOLID STATE IONICS
(2022)
Article
Thermodynamics
Katarina Muzina, Stanislav Kurajica, Filip Brlekovic, Drazan Jozic, Goran Drazic, Lucija Volf, Helena Bach-Rojecky
Summary: In this study, the grain growth kinetics of copper-doped ceria nanoparticles were investigated. It was found that doping with copper improves the thermal stability of ceria, and the sample with 40 mol.% of added copper has the slowest grain growth below 650 degrees C.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Electrochemistry
Prerna Vinchhi, Roma Patel, Indrajit Mukhopadhyay, Abhijit Ray, Ranjan Pati
Summary: This study investigates the impact of Sm3+ doping concentration on the grain boundary ionic conductivity of ceria. Materials were prepared using a modified co-precipitation method and sintered at high temperature to achieve highly dense pellets. Structural analyses confirmed the single phase cubic structure of samaria doped ceria (SDC) nanoparticles, and the ionic conductivity measurements showed superior grain boundary conductivity for certain compositions.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Boyu Li, Eric Croiset, John Z. Wen
Summary: This study investigates the improved cycling stability of CeO2 catalysts by doping different ratios of samarium (Sm) and finds that while stability increases with increasing Sm doping, activity is compromised. It also identifies the important roles of Ce3+ and O-alpha species in controlling catalytic soot oxidation activity.
Article
Multidisciplinary Sciences
Maribel Guzman, Wei Tian, Chantal Walker, Jose E. Herrera
Summary: Doped and undoped Cu2O nanoparticles were prepared and characterized using various techniques, showing that they have a narrow band gap and exhibit a blue shift compared to bulk Cu2O.
ROYAL SOCIETY OPEN SCIENCE
(2022)
Article
Chemistry, Physical
Mariano Santaya, Catalina Elena Jimenz, Mauricio Damian Arce, Emilia Andrea Carbonio, Lucia Maria Toscani, Raul Garcia-Diez, Axel Knop-Gericke, Liliana Veronica Mogni, Marcus Baer, Horacio Esteban Troiani
Summary: Exsolution is a successful functionalization technique used to enhance the catalytic activity of electrodes in solid oxide fuel and electrolyzer cells. This technique aims to produce metallic nano particles on the surface of a host-oxide without altering its structure significantly. The study compares three similar SOFC electrodes and reveals differences in nanoparticle formation and anchoring to the host-oxide. The characteristics of exsolution depend not only on temperature, atmosphere, and reduction times but also on the reduction path.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Thermodynamics
Ricardo I. Castro, Jaime Gallego, Marcos Flores Garcia, Adolfo Marican, Oscar Forero-Doria
Summary: A methodology was developed for determining the adulteration of edible oils based on thermal analysis and statistical models, allowing for the determination of the percentage of mixture by analyzing peaks of different oils.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Materials Science, Paper & Wood
Ricardo I. Castro, Ana Gonzalez-Feliu, Felipe Valenzuela-Riffo, Carolina Parra-Palma, Luis Morales-Quintana
Summary: Evidence suggests that ABA promotes fruit ripening in strawberries by degrading cell wall polymers, especially hemicellulose, as shown through thermogravimetric analysis. Samples treated with an ABA biosynthesis inhibitor maintained thermal stability, indicating a link between thermal stability, transcriptional analysis, and enzymatic activity. These findings provide insight into changes in cell wall polymers during fruit ripening mediated by the ABA hormone.
Article
Medicine, General & Internal
Maria Elvira Balcells, Luis Rojas, Nicole Le Corre, Constanza Martinez-Valdebenito, Maria Elena Ceballos, Marcela Ferres, Mayling Chang, Cecilia Vizcaya, Sebastian Mondaca, Alvaro Huete, Ricardo Castro, Mauricio Sarmiento, Luis Villarroel, Alejandra Pizarro, Patricio Ross, Jaime Santander, Barbara Lara, Marcela Ferrada, Sergio Vargas-Salas, Carolina Beltran-Pavez, Ricardo Soto-Rifo, Fernando Valiente-Echeverria, Christian Caglevic, Mauricio Mahave, Carolina Selman, Raimundo Gazitua, Jose Luis Briones, Franz Villarroel-Espindola, Carlos Balmaceda, Manuel A. Espinoza, Jaime Pereira, Bruno Nervi
Summary: The study did not find evidence of benefit in mortality, length of hospitalization, or mechanical ventilation requirement by immediate addition of CP therapy in the early stages of COVID-19 compared to its use only in case of patient deterioration.
Article
Materials Science, Paper & Wood
Ricardo I. Castro, Marcelo Munoz-Vera, Carolina Parra-Palma, Felipe Valenzuela-Riffo, Carlos R. Figueroa, Luis Morales-Quintana
Summary: The fruit of Fragaria chiloensis, known as Chilean strawberry, is praised for its exceptional taste and aroma. However, it is prone to softening at a high rate. A study on the changes in cell wall-associated polysaccharide contents of Chilean strawberry fruit revealed lower thermal stability in ripe samples and a higher cumulative depolymerization rate. This relationship between cell wall polymer degradation and solid soluble concentration/firmness ratio can help understand fruit development.
Review
Biotechnology & Applied Microbiology
Ricardo I. Castro, Patricio Ramos, Carolina Parra-Palma, Luis Morales-Quintana
Summary: The review highlights Ugni molinae as a plant rich in molecules with strong antioxidant capacity, making it a potential ingredient for new functional food products.
BIOMED RESEARCH INTERNATIONAL
(2021)
Article
Chemistry, Physical
Kimiko Nakajima, Flavio L. Souza, Andre L. M. Freitas, Andrew Thron, Ricardo H. R. Castro
Summary: Nanomaterials can enhance electrochemical performance in batteries, but their high surface areas lead to instability issues. This study investigates the manipulation of surface energies in nanomaterials through doping to improve stability.
CHEMISTRY OF MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Joao A. Baptista, Ricardo A. E. Castro, Mario T. S. Rosado, Teresa M. R. Maria, M. Ramos Silva, Joao Canotilho, M. Ermelinda S. Eusebio
Summary: This study investigates polymorphic pharmaceutical cocrystals formed between pyrimethamine and structurally related coformers caffeine and theophylline. Two (1:1) enantiotropic cocrystal polymorphs were identified for both pyrimethamine:caffeine and pyrimethamine:theophylline. The differential scanning calorimetry is emphasized for guiding the discovery of cocrystal polymorphs.
CRYSTAL GROWTH & DESIGN
(2021)
Review
Materials Science, Multidisciplinary
Ricardo H. R. Castro
Summary: This paper presents the role of interfacial energies in understanding and controlling nanocrystalline complex oxides, and the intentional modification of interfacial energies through ionic doping. It introduces a new perspective on systematically understanding the role of interfacial energies in microstructural control, especially in nanocrystalline processing.
CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE
(2021)
Review
Chemistry, Multidisciplinary
Ana Claudia Paiva-Santos, Ana Luisa Silva, Catarina Guerra, Diana Peixoto, Miguel Pereira-Silva, Mahdi Zeinali, Filipa Mascarenhas-Melo, Ricardo Castro, Francisco Veiga
Summary: The use of nanotechnology in developing efficient drug delivery systems, such as ethosomes, which contain a high concentration of ethanol, has unique advantages in enhancing drug permeation across the skin. Ethosomes show promise as an alternative to traditional liposomes for delivering therapeutic agents for various skin pathologies, with potential applications in acne, psoriasis, alopecia, skin infections, hormonal deficiencies, among others. Further research is needed to fully explore the potential of ethosomal-based formulations in skin delivery of active ingredients.
PHARMACEUTICAL RESEARCH
(2021)
Article
Polymer Science
Ricardo I. Castro, Luis Morales-Quintana, Nancy Alvarado, Luis Guzman, Oscar Forero-Doria, Felipe Valenzuela-Riffo, V. Felipe Laurie
Summary: The study aimed to characterize and optimize the formation of molecular complexes using calcium alginate and reduced glutathione, with varying concentrations of calcium and GSH analyzed for their influence on microcapsule production. The optimal conditions proposed by response surface methodology were found to result in a theoretical concentration of 0.043 mg GSH per mg of CAG complex.
Article
Agronomy
Ricardo I. Castro, Marcelo Munoz-Vera, Luis Morales-Quintana
Summary: A comparative study of the changes in the physicochemical properties of the cell wall-associated polysaccharide contents of two strawberry fruit cultivars, Cristal and Portola, revealed that Cristal sample exhibited higher thermal stability than Portola sample.
Article
Biochemistry & Molecular Biology
Luis Guzman, Cristobal Parra-Cid, Etiennette Guerrero-Munoz, Carlos Pena-Varas, Efrain Polo-Cuadrado, Yorley Duarte, Ricardo I. Castro, Luz Stella Nerio, Ramiro Araya-Maturana, Tewodros Asefa, Javier Echeverria, David Ramirez, Oscar Forero-Doria
Summary: This study evaluated the antimicrobial properties of different ILs, finding that some exhibit good antibacterial activity against S. aureus, E. coli, and P. aeruginosa. Particularly, tert-butyl N-methylphenolimidazolium salts showed the best antibacterial efficacy. Furthermore, the antimicrobial effectiveness was found to be influenced by the alkyl chain length and substituents on the phenolic ring.
BIOORGANIC CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Joao A. Baptista, Mario T. S. Rosado, Ricardo A. E. Castro, Antonio O. L. Evora, Teresa M. R. Maria, Manuela Ramos Silva, Joao Canotilho, M. Ermelinda S. Eusebio
Summary: In this study, co-crystal screening was conducted for DHFR inhibitors, revealing low propensities for co-crystallization with certain co-formers. Successful synthesis of multi-component solid forms was achieved for all target molecules, and the crystalline structures of co-crystals and solvates were determined. The study demonstrated the potential use of the pharmacophore of DHFR inhibitors as a guide for co-crystal screening, showing similarities in the solid state associations and molecular aggregations in the co-crystals.
Article
Materials Science, Ceramics
Andre A. Bernardes, Andre L. da Silva, Jefferson Bettini, Jair C. C. Freitas, Ricardo H. R. Castro, Douglas Gouvea
Summary: Interface segregation plays a crucial role in the properties of nanocrystalline ceramics. This study investigates the spatial distribution of Li+ dopants in magnesium aluminate spinel nanoparticles and reveals a clear correlation between the microstructure of the nanoparticles and the distribution of Li+.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Critical Care Medicine
Jan Bakker, James M. Horowitz, Jackie Hagedorn, Sam Kozloff, David Kaufman, Ricardo Castro
