52 results match your criteria: "Instituto Universitario de InvestigaciĂłn en MicroscopĂ­a ElectrĂłnica y Materiales[Affiliation]"

Exploring the Photocatalytic Efficiency of Gold Nanoparticles Deposited on Ni-Al-Zr-Layered Double Hydroxides for Selective Glucose Oxidation.

Molecules

December 2024

Laboratoire de Réactivité et Chimie des Solides (LRCS), UMR CNRS 7314, Université de Picardie Jules Verne, Hub de L'énergie, 15 rue Baudelocque, FR-80000 Amiens, France.

Confronting escalating challenges in energy security and environmental sustainability has intensified interest in renewable sources for fuels and chemicals. Among the most promising alternatives, sugars derived from biomass are emerging as a cornerstone in advancing an environmentally sustainable economy. Within this framework, the development of sunlight-driven carbohydrate oxidation is of significant interest, as it enables the production of a broad spectrum of high-value, bio-sourced chemicals through eco-friendly processes.

View Article and Find Full Text PDF

The use of ecofriendly natural minerals in photocatalytic processes to deal with the antimicrobial activity (AA) associated with antibiotics in aqueous systems is still incipient. Therefore, in this work, the capacity of a natural iron material (NIM) in photo-treatments, generating reactive species, to remove the antibiotic enrofloxacin and decrease its associated AA from water is presented. Initially, the fundamental composition, oxidation states, bandgap, point of zero charge, and morphological characteristics of the NIM were determined, denoting the NIM's feasibility for photocatalytic processes.

View Article and Find Full Text PDF

Photoactive broad-spectrum dressings with antimicrobial and antitumoral properties.

Biomater Adv

December 2024

Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados (IITEMA), Universidad Nacional de Río Cuarto and Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Campus Universitario, 5800 Río Cuarto, Argentina. Electronic address:

In this work the development of photoactive dressings (PAD) with dual purpose, is presented. These PAD can be used for the topical treatment of persistent infections caused by fungi and bacteria and are also applicable in light antitumor therapy for carcinoma. The synthesized PAD were designed employing conjugated polymer nanoparticles (CPN) doped with platinum porphyrin which serve as polymerization photoinitiators and photosensitizers for the production of reactive oxygen species (ROS).

View Article and Find Full Text PDF

Promoting endogenous neurogenesis for brain repair is emerging as a promising strategy to mitigate the functional impairments associated with various neurological disorders characterized by neuronal death. Diterpenes featuring tigliane, ingenane, jatrophane and lathyrane skeletons, frequently found in Euphorbia plant species, are known protein kinase C (PKC) activators and exhibit a wide variety of pharmacological properties, including the stimulation of neurogenesis. Microbial transformation of these diterpenes represents a green and sustainable methodology that offers a hitherto little explored approach to obtaining novel derivatives and exploring structure-activity relationships.

View Article and Find Full Text PDF

Exfoliated graphite (ExG) embedded in a polymeric matrix represents an accessible, cost-effective, and sustainable method for generating nanosized graphite-based polymer composites with multifunctional properties. This review article analyzes diverse methods currently used to exfoliate graphite into graphite nanoplatelets, few-layer graphene, and polymer-assisted graphene. It also explores engineered methods for small-scale pilot production of polymer nanocomposites.

View Article and Find Full Text PDF

Induced-aggregates in photocatalysis: An unexplored approach to reduce the noble metal co-catalyst content.

J Colloid Interface Sci

December 2024

Departamento de Ciencia de los Materiales, Ingeniería Metalúrgica y Química Inorgánica, Universidad de Cádiz, Spain; Instituto Universitario de Investigación en Microscopía Electrónica y Materiales (IMEYMAT), Universidad de Cádiz, Spain. Electronic address:

Photocatalysis has emerged as a promising and environmentally sustainable solution to produce high-purity hydrogen through ethanol photoreforming. It is commonly accepted that adding co-catalysts, especially noble metals, significantly enhances the catalytic activity of semiconductors. However, the high cost of noble metals such as Pt may limit the real application of this emerging technology.

View Article and Find Full Text PDF

Background: Sarcopenia, the gradual and generalized loss of muscle mass and function with ageing, is one of the major health problems in older adults, given its high prevalence and substantial socioeconomic implications. Despite the extensive efforts to reach consensus on definition and diagnostic tests and cut-offs for sarcopenia, there is an urgent and unmet need for non-invasive, specific and sensitive biomarkers for the disease. Extracellular vesicles (EVs) are present in different biofluids including plasma, whose cargo reflects cellular physiology.

View Article and Find Full Text PDF

Enhancing antioxidant properties of CeO nanoparticles with Nd doping: structural, biological, and machine learning insights.

Biomater Sci

April 2024

Tecnologico de Monterrey, Escuela de ingenierĂ­a y Ciencias, Av. Gral. RamĂłn Corona No 2514, Colonia Nuevo MĂ©xico, Zapopan, Jalisco, 45121, Mexico.

The antioxidant capabilities of nanoparticles are contingent upon various factors, including their shape, size, and chemical composition. Herein, novel Nd-doped CeO nanoparticles were synthesized and the neodymium content was varied to investigate the synergistic impact on the antioxidant properties of CeO nanoparticles. Incorporating Nd induced changes in lattice parameters and significantly altered the morphology from nanoparticles to nanorods.

View Article and Find Full Text PDF

Alternative processes to produce chitin, chitosan, and their oligomers.

Carbohydr Polym

May 2024

Departamento de Suelos y Recursos Naturales, Facultad de AgronomĂ­a, Campus ConcepciĂłn, Casilla 160-C, Universidad de ConcepciĂłn, Chile; Laboratory of Biofilms and Environmental Microbiology, Center of Biotechnology, Universidad de ConcepciĂłn, Barrio Universitario s/n, ConcepciĂłn, Chile.

Sustainable recovery of chitin and its derivatives from shellfish waste will be achieved when the industrial production of these polymers is achieved with a high control of their molecular structure, low costs, and acceptable levels of pollution. Therefore, the conventional chemical method for obtaining these biopolymers needs to be replaced or optimized. The goal of the present review is to ascertain what alternative methods are viable for the industrial-scale production of chitin, chitosan, and their oligomers.

View Article and Find Full Text PDF

Biophysical evaluation of antiparallel triplexes for biosensing and biomedical applications.

Int J Biol Macromol

April 2024

Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain; Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Madrid, Spain. Electronic address:

Polypyrimidine sequences can be targeted by antiparallel clamps forming triplex structures either for biosensing or therapeutic purposes. Despite its successful implementation, their biophysical properties remain to be elusive. In this work, PAGE, circular dichroism and multivariate analysis were used to evaluate the properties of PPRHs directed to SARS-CoV-2 genome.

View Article and Find Full Text PDF

A solventless and acid-catalyzed condensation of -perfluoroalkyl-dipyrromethanes with selected benzaldehydes was used to prepare ten different bilanes that were isolated before their oxidation into -AB-corroles bearing two -perfluoroalkyl groups. Macrocycles bearing long chains (CF or CF) are key precursors to afford ABC-corroles having a -acyl substituent when subjected to a mild and basic hydrolysis affecting one of the alkyl substituents.

View Article and Find Full Text PDF

Background /objective: The phospholipid 1,2-dipalmitoyl-rac-glycero-3-phosphatidylethanolamine (PE) comprises two fatty acid chains: glycerol, phosphate, and ethanolamine. PE participates in critical cellular processes such as apoptosis and autophagy, which places it as a target for designing new therapeutic alternatives in diseases such as pulmonary fibrosis. Therefore, this study aimed obtain PE through a six-step organic synthesis pathway and determine its biological effect on apoptosis induction in normal human lung fibroblasts (NHLF).

View Article and Find Full Text PDF

Formation of Highly Emissive Anthracene Excimers for Aggregation-Induced Emission/Self-Assembly Directed (Bio)imaging.

ACS Appl Mater Interfaces

September 2023

Unidad nanoDrug. Facultad de Farmacia de Albacete, Universidad de Castilla-La Mancha, 02008 Albacete, Spain.

AIEgens have emerged as a promising alternative to molecular rotors in bioimaging applications. However, transferring the concept of aggregation-induced emission (AIE) from solution to living systems remains a challenge. Given the highly heterogeneous nature and the compartmentalization of the cell, different approaches are needed to control the self-assembly within the crowded intricate cellular environment.

View Article and Find Full Text PDF

Reduced Tiara-like Palladium Complex for Suzuki Cross-Coupling Reactions.

Chemistry

November 2023

Department of Chemical and Pharmaceutical Sciences, INSTM, UdR Trieste, University of Trieste, Trieste, 34127, Italy.

The design of highly active and structurally well-defined catalysts has become a crucial issue for heterogeneous catalysed reactions while reducing the amount of catalyst employed. Beside conventional synthetic routes, the employment of polynuclear transition metal complexes as catalysts or catalyst precursors has progressively intercepted a growing interest. These well-defined species promise to deliver catalytic systems where a strict control on the nuclearity allows to improve the catalytic performance while reducing the active phase loading.

View Article and Find Full Text PDF

Robust cascade controller for the power factor of the three-phase supply and the induction motor velocity.

ISA Trans

September 2023

Facultad de Ingenieria Electrica, Universidad Michoacana de San Nicolas de Hidalgo, Morelia, Mexico. Electronic address:

It is well known that induction motors consume active and reactive energy from the utility grid to operate; additionally, when a power converter drives the motor, a high content of current harmonics is produced, and both circumstances decrease the utility grid power factor, which later requires to be improved. To this end, this paper presents a novel complete solution through a robust control system employed in a back-to-back topology power converter to deliver, instead of consuming, regulated reactive power toward the main grid, which comes from a capacitor bank in a DC-bus. This salient feature of delivering reactive power, and simultaneously, regulating the speed for an induction motor, becomes one of the contributions of this work to enhance the power factor.

View Article and Find Full Text PDF

Computational Study of the Influence of α/β-Phase Ratio and Porosity on the Elastic Modulus of Ti-Based Alloy Foams.

Materials (Basel)

May 2023

Instituto de QuĂ­mica, Facultad de Ciencias, Pontificia Universidad CatĂłlica de ValparaĂ­so, ValparaĂ­so 2373223, Chile.

This work aims to perform a computational analysis on the influence that microstructure and porosity have on the elastic modulus of Ti-6Al-4V foams used in biomedical applications with different α/β-phase ratios. The work is divided into two analyses, first the influence that the α/β-phase ratio has and second the effects that porosity and α/β-phase ratio have on the elastic modulus. Two microstructures were analyzed: equiaxial α-phase grains + intergranular β-phase (microstructure A) and equiaxial β-phase grains + intergranular α-phase (microstructure B).

View Article and Find Full Text PDF

Reusable antimicrobial antibiotic-free dressings obtained by photopolymerization.

Biomater Adv

June 2023

Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados (IITEMA), Universidad Nacional de Río Cuarto, Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Campus Universitario, 5800 Río Cuarto, Argentina. Electronic address:

In recent years significant efforts have been made to develop new materials for wound dressing with improved healing properties. However, the synthesis methods usually employed to this end are often complex or require several steps. We describe here the synthesis and characterization of antimicrobial reusable dermatological wound dressings based on N-isopropylacrylamide co-polymerized with [2-(Methacryloyloxy) ethyl] trimethylammonium chloride hydrogels (NIPAM-co-METAC).

View Article and Find Full Text PDF

The reactions of 2-naphthylamine and methyl 6-amino-2-naphthoate with formalin and paraformaldehyde were studied experimentally, spectrally, and by quantum chemical calculations. It was found that neither the corresponding aminals nor imines were formed under the described conditions but could be prepared and spectrally characterized at least in situ under modified conditions. Several of the previously undescribed intermediates and by-products were isolated or at least spectrally characterized.

View Article and Find Full Text PDF

Rotational dive into the water clusters on a simple sugar substrate.

Proc Natl Acad Sci U S A

February 2023

Deutsches Elektronen-Synchrotron (DESY), D-22607 Hamburg, Germany.

Most biomolecular activity takes place in aqueous environments, and it is strongly influenced by the surrounding water molecules. The hydrogen bond networks that these water molecules form are likewise influenced by their interactions with the solutes, and thus, it is crucial to understand this reciprocal process. Glycoaldehyde (Gly), often considered the smallest sugar, represents a good template to explore the steps of solvation and determine how the organic molecule shapes the structure and hydrogen bond network of the solvating water cluster.

View Article and Find Full Text PDF

Enzyme-Free Colorimetric Method for Fast Detection of PIK3CA Gene Mutation by Praseodymia Nanorods.

Anal Chem

February 2023

Departamento de Ciencia de los Materiales, Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias and Instituto Universitario de Investigación en Microscopía Electrónica y Materiales (IMEYMAT), Universidad de Cádiz, Puerto Real, Cádiz E-11510, Spain.

The frequently mutated phosphatidylinositol 3-kinase catalytic subunit alpha (PIK3CA) gene is associated with multiple tumors and endocytosis of viruses. Identification of muted nucleotides at the hotspot can help in finding the susceptible people who are vulnerable to cancers and viruses. Herein, a simple enzyme-free colorimetric method is developed for the quick detection of PIK3CA gene mutations.

View Article and Find Full Text PDF

Tailoring the Magnetic and Structural Properties of Manganese/Zinc Doped Iron Oxide Nanoparticles through Microwaves-Assisted Polyol Synthesis.

Nanomaterials (Basel)

September 2022

Instituto de Ciencia de Materiales de Madrid, ICMM/CSIC, C. Sor Juana Inés de la Cruz 3, 28049 Madrid, Spain.

Tuning the fundamental properties of iron oxide magnetic nanoparticles (MNPs) according to the required biomedical application is an unsolved challenge, as the MNPs' properties are affected by their composition, their size, the synthesis process, and so on. In this work, we studied the effect of zinc and manganese doping on the magnetic and structural properties of MNPs synthesized by the microwave-assisted polyol process, using diethylene glycol (DEG) and tetraethylene glycol (TEG) as polyols. The detailed morpho-structural and magnetic characterization showed a correspondence between the higher amounts of Mn and smaller crystal sizes of the MNPs.

View Article and Find Full Text PDF

A new photoinitiator system (PIS) based on riboflavin (Rf), triethanolamine, and multiwalled carbon nanobutes (MWCNTs) is presented for visible-light-induced photopolymerization of acrylic monomers. Using this PIS, photopolymerization of acrylamide and other acrylic monomers was quantitative in seconds. The intervention mechanism of CNTs in the PIS was studied deeply, proposing a surface interaction of MWCNTs with Rf which favors the radical generation and the initiation step.

View Article and Find Full Text PDF

The work assesses the performance of nanocarriers from amphiphilic block copolymers with functional azobenzene or coumarin moieties for delivery of paclitaxel. Placlitaxel was encapsulated by the nanoprecipitation method. Characterisations were performed by DLS, TEM, Zeta potential and HPLC.

View Article and Find Full Text PDF

The relative populations of Cu isomers depend to a great extent on the temperature. Density functional theory and nanothermodynamics can be combined to compute the geometrical optimization of isomers and their spectroscopic properties in an approximate manner. In this article, we investigate entropy-driven isomer distributions of Cu clusters and the effect of temperature on their IR spectra.

View Article and Find Full Text PDF