Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Más filtros










Intervalo de año de publicación
1.
Nanomaterials (Basel) ; 14(1)2023 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-38202528

RESUMEN

This study investigates electrospun fibers of metal-organic frameworks (MOFs), particularly CuBTC and ZIF-8, in polyacrylonitrile (PAN) for the solid-phase extraction (SPE) of Tamoxifen (TAM) and its metabolites (NDTAM, ENDO, and 4OHT) from human blood plasma. The focus is on the isolation, pre-concentration, and extraction of the analytes, aiming to provide a more accessible and affordable breast cancer patient-monitoring technology. The unique physicochemical properties of MOFs, such as high porosity and surface area, combined with PAN's stability and low density, are leveraged to improve SPE efficiency. The study meticulously examines the interactions of these MOFs with the analytes under various conditions, including elution solvents and protein precipitators. Results reveal that ZIF-8/PAN composites outperform CuBTC/PAN and PAN alone, especially when methanol is used as the protein precipitator. This superior performance is attributed to the physicochemical compatibility between the analytes' properties, like solubility and polarity, and the MOFs' structural features, including pore flexibility, active site availability, surface polarity, and surface area. The findings underscore MOFs' potential in SPE applications and provide valuable insights into the selectivity and sensitivity of different MOFs towards specific analytes, advancing more efficient targeted extraction methods in biomedical analysis.

2.
Int J Mol Sci ; 23(14)2022 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-35887350

RESUMEN

Photosensitive supramolecular systems have garnered attention due to their potential to catalyze highly specific tasks through structural changes triggered by a light stimulus. The tunability of their chemical structure and charge transfer properties provides opportunities for designing and developing smart materials for multidisciplinary applications. This review focuses on the approaches reported in the literature for tailoring properties of the photosensitive supramolecular systems, including MOFs, MOPs, and HOFs. We discuss relevant aspects regarding their chemical structure, action mechanisms, design principles, applications, and future perspectives.

3.
Biosensors (Basel) ; 11(5)2021 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-33919464

RESUMEN

Paper-based analytical devices (PADs) and Electrospun Fiber-Based Biosensors (EFBs) have aroused the interest of the academy and industry due to their affordability, sensitivity, ease of use, robustness, being equipment-free, and deliverability to end-users. These features make them suitable to face the need for point-of-care (POC) diagnostics, monitoring, environmental, and quality food control applications. Our work introduces new and experienced researchers in the field to a practical guide for fibrous-based biosensors fabrication with insight into the chemical and physical interaction of fibrous materials with a wide variety of materials for functionalization and biofunctionalization purposes. This research also allows readers to compare classical and novel materials, fabrication techniques, immobilization methods, signal transduction, and readout. Moreover, the examined classical and alternative mathematical models provide a powerful tool for bioanalytical device designing for the multiple steps required in biosensing platforms. Finally, we aimed this research to comprise the current state of PADs and EFBs research and their future direction to offer the reader a full insight on this topic.


Asunto(s)
Técnicas Biosensibles , Papel , Diseño de Equipo , Humanos , Nanofibras , Sistemas de Atención de Punto
4.
Polymers (Basel) ; 12(6)2020 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-32560281

RESUMEN

Polymer solutions with different concentrations of SU-8 2002/poly(ethylene) glycol/tetrabutyl ammonium tetrafluoroborate (SU-8/PEO/TBATFB) were electrospun in a low-voltage near-field electrospinning platform (LVNFES) at different velocities. Their diameters were related to the concentration contents as well as to their Deborah (De) numbers, which describes the elasticity of the polymer solution under determined operating conditions. We found a direct correlation between the concentration of PEO/TBATFB, the De and the diameter of the fibers. Fibers with diameters as thin as 465 nm can be achieved for De ≈ 1.

5.
Environ Microbiol ; 19(8): 3268-3282, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28618142

RESUMEN

This article explores the functional diversity and redundancy in a bacterial metacommunity constituted of three habitats (sediment, water column and fish gut) in a coastal lagoon under anthropogenic pressure. Comprehensive functional gene arrays covering a wide range of ecological processes and stress resistance genes to estimate the functional potential of bacterial communities were used. Then, diversity partitioning was used to characterize functional diversity and redundancy within (α), between (ß) and across (γ) habitats. It was showed that all local communities exhibit a highly diversified potential for the realization of key ecological processes and resistance to various environmental conditions, supporting the growing evidence that macro-organisms microbiomes harbour a high functional potential and are integral components of functional gene dynamics in aquatic bacterial metacommunities. Several levels of functional redundancy at different scales of the bacterial metacommunity were observed (within local communities, within habitats and at the metacommunity level). The results suggested a high potential for the realization of spatial ecological insurance within this ecosystem, that is, the functional compensation among microorganisms for the realization and maintenance of key ecological processes, within and across habitats. Finally, the role of macro-organisms as dispersal vectors of microbes and their potential influence on marine metacommunity dynamics were discussed.


Asunto(s)
Bacterias/metabolismo , Peces/microbiología , Microbioma Gastrointestinal , Sedimentos Geológicos/microbiología , Microbiología del Agua , Animales , Bacterias/genética , Biodiversidad , Ecología , Ecosistema , Ambiente , Agua
6.
PLoS One ; 7(7): e40679, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22792395

RESUMEN

The concept of ß-diversity, defined as dissimilarity among communities, has been widely used to investigate biodiversity patterns and community assembly rules. However, in ecosystems with high taxonomic ß-diversity, due to marked environmental gradients, the level of functional ß-diversity among communities is largely overlooked while it may reveal processes shaping community structure. Here, decomposing biodiversity indices into α (local) and γ (regional) components, we estimated taxonomic and functional ß-diversity among tropical estuarine fish communities, through space and time. We found extremely low functional ß-diversity values among fish communities (<1.5%) despite high dissimilarity in species composition and species dominance. Additionally, in contrast to the high α and γ taxonomic diversities, α and γ functional diversities were very close to the minimal value. These patterns were caused by two dominant functional groups which maintained a similar functional structure over space and time, despite the strong dissimilarity in taxonomic structure along environmental gradients. Our findings suggest that taxonomic and functional ß-diversity deserve to be quantified simultaneously since these two facets can show contrasting patterns and the differences can in turn shed light on community assembly rules.


Asunto(s)
Biodiversidad , Peces/clasificación , Clima Tropical , Animales , Ecosistema , Golfo de México , Modelos Estadísticos , Dinámica Poblacional
7.
Ecol Appl ; 20(6): 1512-22, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20945756

RESUMEN

Human activities have strong impacts on ecosystem functioning through their effect on abiotic factors and on biodiversity. There is also growing evidence that species functional traits link changes in species composition and shifts in ecosystem processes. Hence, it appears to be of utmost importance to quantify modifications in the functional structure of species communities after human disturbance in addition to changes in taxonomic structure. Despite this fact, there is still little consensus on the actual impacts of human-mediated habitat alteration on the components of biodiversity, which include species functional traits. Therefore, we studied changes in taxonomic diversity (richness and evenness), in functional diversity, and in functional specialization of estuarine fish communities facing drastic environmental and habitat alterations. The Terminos Lagoon (Gulf of Mexico) is a tropical estuary of primary concern for its biodiversity, its habitats, and its resource supply, which have been severely impacted by human activities. Fish communities were sampled in four zones of the Terminos Lagoon 18 years apart (1980 and 1998). Two functions performed by fish (food acquisition and locomotion) were studied through the measurement of 16 functional traits. Functional diversity of fish communities was quantified using three independent components: richness, evenness, and divergence. Additionally, we measured the degree of functional specialization in fish communities. We used a null model to compare the functional and the taxonomic structure of fish communities between 1980 and 1998. Among the four largest zones studied, three did not show strong functional changes. In the northern part of the lagoon, we found an increase in fish richness but a significant decrease of functional divergence and functional specialization. We explain this result by a decline of specialized species (i.e., those with particular combinations of traits), while newly occurring species are redundant with those already present. The species that decreased in abundance have functional traits linked to seagrass habitats that regressed consecutively to increasing eutrophication. The paradox found in our study highlights the need for a multifaceted approach in the assessment of biodiversity changes in communities under pressure.


Asunto(s)
Ecosistema , Peces/clasificación , Peces/fisiología , Animales , Conservación de los Recursos Naturales , México , Océanos y Mares , Dinámica Poblacional , Clima Tropical
8.
Rev. biol. trop ; 51(3/4): 783-793, sept.-dic. 2003. tab, mapas, graf
Artículo en Español | LILACS | ID: lil-365918

RESUMEN

The structure of the fish community in Terminos Lagoon, Campeche, is analyzed on the base the description of the abundance, distribution, length composition and identification of the dominant species. The results are discussed and compared with the published information. 437 trawl tows were made in 19 monthly collection in 23 sites between September 1997 to March 1999. A total of 25,588 individual with a total weight of 601.5 kg were grouped in 107 species, 76 gender and 37 families. The abundance of the fish community showed the following intervals in temporal scale: 0.395 to 0.895 ind/m2; 8.637 to 18.316 g/m2 and 18.358 to 34.837 g/ind. The Shannon index oscillated between 1.875 and 3.995 and 4.94 and 7.88 respectively. 18 dominant species were identified. The most important species by its numerical abundance and appearance frequency is Arius melanopus that represents to the 26.5 of the total catch followed by Diapterus rhombeus with 18.9. As dominant species, Bairdiella chrysura, B. ronchus, Archosargus rhomboidalis, Eugerres plumieri, Cynoscion arenarius and Chaetodipterus faber, are fishing resources with local and regional value.


Asunto(s)
Animales , Peces , Agua Dulce , Ecosistema , México , Densidad de Población , Estaciones del Año
9.
Rev Biol Trop ; 51(3-4): 783-93, 2003.
Artículo en Español | MEDLINE | ID: mdl-15162786

RESUMEN

The structure of the fish community in Terminos Lagoon, Campeche, is analyzed on the base the description of the abundance, distribution, length composition and identification of the dominant species. The results are discussed and compared with the published information. 437 trawl tows were made in 19 monthly collection in 23 sites between September 1997 to March 1999. A total of 25,588 individual with a total weight of 601.5 kg were grouped in 107 species, 76 gender and 37 families. The abundance of the fish community showed the following intervals in temporal scale: 0.395 to 0.895 ind/m2; 8.637 to 18.316 g/m2 and 18.358 to 34.837 g/ind. The Shannon index oscillated between 1.875 and 3.995 and 4.94 and 7.88 respectively. 18 dominant species were identified. The most important species by its numerical abundance and appearance frequency is Arius melanopus that represents to the 26.5% of the total catch followed by Diapterus rhombeus with 18.9%. As dominant species, Bairdiella chrysura, B. ronchus, Archosargus rhomboidalis, Eugerres plumieri, Cynoscion arenarius and Chaetodipterus faber, are fishing resources with local and regional value.


Asunto(s)
Peces/clasificación , Agua Dulce , Animales , Biodiversidad , México , Densidad de Población , Estaciones del Año
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...