Laccase amperometric biosensors were developed to detect the catechol compound. The laccase enzyme (LAC) immobilization was performed on nanostructures of (a) titania (TiO₂); (b) titania/Nafion ...(TiO₂/NAF) (both immobilized by the sol-gel method) and a third nanostructure, which consisted of a single biosensor composite of Nafion and laccase enzyme denoted as NAF/LAC. The Nafion was deposited on a graphite electrode and used to avoid "cracking" on the matrix. The TiO₂ particle size was an average of 66 nm. FTIR spectroscopy vibration modes of different composites were determined. The electrochemical behavior of the biosensor was studied using electrochemical spectroscopy (EIS) and cyclic voltammetry (CV). The biosensor based on TiO₂/NAF/LAC presented the best electro-chemical properties with regard to sensitivity, stability and detection limit after a period of 22 days.
Bacterial cellulose (BC) membranes are an excellent ecopolymer product that has been proposed for many applications, including acoustic, biomedical, and fabrics. However, those uses require the ...membranes’ exposure to environmental conditions related to shelf storage, washing, or excess of humidity that are not usually evaluated when developing new materials. In this work, we investigated the effect of high and low temperature, and high humidity accelerated exposure on the physical and mechanical properties of BC membranes prepared from Kombucha fermentation. We prepared BC membranes following standard protocols and subjected them to a composite temperature/humidity accelerated cyclic assay. The mechanical and physical properties of the membranes were measured before and after the assay. We found that the ultimate tensile strength, elastic modulus, and elongation at break significantly changed after the assay. We also observed a few morphology changes, but no changes in the DSC and IR determinations. Our results suggest that environmental tests should be performed in every biodegradable polymer according to their intended use to determine their applications fully.
Exosomes are microvesicles that actively participate in signaling mechanisms and depending on their content can contribute to the development of different pathologies, such as diabetes and ...cardiovascular disease.
The aim of this study was to evaluate the association of cystatin C, CD26, and CD14 proteins in serum exosomes from patients with Type 2 Diabetes (T2D), metabolic syndrome (MetS), and atherogenic index of plasma (AIP).
Serum exosomes were isolated by ultracentrifugation from 147 individuals with and without diabetes. Both anthropometric and metabolic parameters were registered from everyone. The levels of exosomal proteins cystatin C, CD26, and CD14 were quantified by ELISA. The association between protein levels and T2D or atherogenic risk factors was analyzed by linear regression and generalized regression models.
We observed a significant correlation of increased glucose with elevated levels of Cystatin C, and an effect of T2D on the levels of CD26 (β = 45.8 pg/µg;
= 0.001) and CD14 (β = 168 pg/µg;
< 0.001) compared to subjects without T2D. CD14 was significantly related to T2D, metabolic syndrome, glucose, and the Atherogenic Index of Plasma (AIP). Additionally, we observed a significant effect of metabolic syndrome MetS on the increase of exosomal Cystatin C and CD14.
T2D may contribute to the increase of CD14 protein contained in exosomes, as well as to the predisposition of atherogenic events development due to its relationship with the increase in serum triglyceride concentrations and the AIP score. Finally, the increased levels of CD14 and Cystatin C in exosomes are related to MetS. The analysis of exosome contents of diabetic patients remains an incipient field, so extensive characterization is crucial for their use as biomarkers or to analyze their possible contribution to diabetic complications.
Polyaniline (PANI) composites have gained momentum as supercapacitive materials due to their high energy density and power density. However, some drawbacks in their performance remain, such as the ...low stability after hundreds of charge-discharge cycles and limitations in the synthesis scalability. Herein, we report for the first time PANI-Graphitic oxidized carbon nitride composites as potential supercapacitor material. The biomimetic polymerization of aniline assisted by hematin, supported by phosphorous and oxygen-modified carbon nitrides (g-POCN and g-OCN, respectively), achieved up to 89% yield. The obtained PAI/g-POCN and PANI/g-OCN show enhanced electrochemical properties, such as conductivity of up to 0.0375 S/cm, specific capacitances (Cs) of up to 294 F/g (at high current densities, 5 A/g) and a stable operation after 500 charge-discharge cycles (at 3 A/g). In contrast, the biomimetic synthesis of Free PANI, assisted by stabilized hematin in cosolvents, exhibited lower performance properties (65%). Due to their structural differences, the electrochemical properties of Free PANI (conductivity of 0.0045 S/cm and Cs of up to 82 F/g at 5 A/g) were lower than those of nanostructured PANI/g-POCN and g-OCN supports, which provide stability and improve the properties of biomimetically synthesized PANI. This work reveals the biomimetic synthesis of PANI, assisted by hematin supported by modified carbon nitrides, as a promising strategy to produce nanostructured supercapacitors with high performance.
El presente trabajo tuvo como objetivo evaluar el impacto del componente III en la modalidad B.1, (sobre Conservación y Restauración) del Programa Nacional Forestal en los ejidos Eugenio Echeverría ...Castellot y La Guadalupe, en el municipio de Calakmul, Campeche bajo los enfoques socioambiental y ecológico en el periodo 2010-2012. El programa evaluado no cumple con los objetivos para los que fue diseñado en los dos ejidos estudiados, ya que las condiciones socioeconómicas de la población objetivo no mejoraron y las áreas reforestadas presentaron niveles de sobrevivencia menores de 6% a tres años de su implementación. Palabras claves: política forestal, evaluación de impacto, reforestación, conservación, Calakmul.
The derived materials obtained from the sol-gel process have been used in various technological applications, such as solar cells, intelligent coatings, catalysis, and, more recently, the fabrication ...of bioreceptors. The objective of this study was to develop a bioreceptor consisting of a titania-based nanostructure, which was synthesized using the sol-gel method. This nanostructure was immersed in a solution containing laccase and Nafion and integrated into a graphite-based electrode (TiO2/NAF/LAC). This device is called a bioreceptor and is used to detect gallic acid. The nanostructure was characterized by x-ray diffraction, Raman spectroscopy, and scanning electron microscopy (SEM). Particle size was measured using a nanosizer. Cyclic voltammetry (CV) tests were performed on a bioreceptor. In this study, the predominant phase of TiO2 was anatase, and the obtained nanoparticles had an average size of 66 nm. The CV tests of the bioreceptor showed an oxidation response that increased as the concentration of gallic acid in the solution increased, with a detection limit of 0.125 μM, as well as a wide linear range that varied from 0.125 to 175 μM and a factor correlation of 0.9968. As a result, it was possible to develop a bioreceptor capable of immobilizing laccase to detect gallic acid.
Immunocompromised patients have an increased risk of developing severe COVID disease, as well as a tendency to suboptimal responses to vaccines. The objective of this study was to evaluate the ...specific cellular and humoral adaptive immune responses of a cohort of kidney transplant recipients (KTR) after 3 doses of mRNA-1273 vaccine and to determinate the main factors involved.
Prospective observational study in 221 KTR (149 non infected), 55 healthy volunteers (HV) and 23 dialysis patients (DP). We evaluated anti-spike (by quantitative chemiluminescence immunoassay) and anti-nucleocapsid IgG (ELISA), percentage of TCD4
and TCD8
lymphocytes producing IFNγ against S-protein by intracellular flow cytometry after Spike-specific 15-mer peptide stimulation and serum neutralizing activity (competitive ELISA) at baseline and after vaccination.
Among COVID-19
KTR, 54.2% developed cellular and humoral response after the third dose (vs 100% in DP and 91.7% in HV), 18% only showed cell-mediated response, 22.2% exclusively antibody response and 5.6% none. A correlation of neutralizing activity with both the IgG titer (r=0.485, p<0.001) and the percentage of S-protein-specific IFNγ-producing CD8-T cells (r=0.198, p=0.049) was observed. Factors related to the humoral response in naïve KTR were: lymphocytes count pre-vaccination >1000/mm
4.68 (1.72-12.73, p=0.003, eGFR>30 mL/min 7.34(2.72-19.84), p<0.001, mTOR inhibitors 6.40 (1.37-29.86), p=0.018. Infected KTR developed a stronger serologic response than naïve patients (96.8 vs 75.2%, p<0.001).
KTR presented poor cellular and humoral immune responses following vaccination with mRNA-1273. The immunosuppression degree and kidney function of these patients play an important role, but the only modifiable factor with a high impact on humoral immunogenicity after a booster dose was an immunosuppressive therapy including a mTOR inhibitor. Clinical trials are required to confirm these results.
Introducción y objetivos: Los arbustos de ambientes de alta montaña desempeñan un papel clave en el mantenimiento y el funcionamiento de procesos ecosistémicos. Sin embargo, los estudios para conocer ...su morfología y su asignación de asimilados son escasos. El objetivo de este trabajo es cuantificar la materia seca y analizar la morfología de Senecio oreophyton y Baccharis tola ssp. tola, en los Andes centrales de Argentina y proponer ecuaciones alométricas.
M&M: El estudio se realizó en la Puna Austral, provincia de San Juan. Se seleccionaron 60 plantas de S. oreophyton y de B. tola. En cada ejemplar se midieron las variables biométricas para estimar la materia seca. Se fotografiaron las vistas lateral y superior para estimar su morfología. Cada ejemplar fue cosechado y diferenciado en tallo, hojas y raíces.
Resultados: La forma geométrica de S. oreophyton fue un cono invertido y de B. tola una semiesfera. En la materia seca de B. tola encontramos valores similares en tallos y hojas, y valores bajos en raíz, mientras que en S. oreophyton la materia seca fue mayor en tallos, siguiendo raíz y luego hojas. Se establecieron ecuaciones alométricas para cada componente a partir de mediciones directas de campo.
Conclusiones: La partición de materia seca encontrada para ambos arbustos indicaría una fuerte asociación de la morfología de la planta y su estrategia para sobrevivir en condiciones de altura. Este trabajo es un aporte al conocimiento sobre las características morfológicas de arbustos leñosos y sus interacciones ambientales para la conservación y manejo de ecosistemas de montaña.
Conventional and commercially available DNA extraction methods have several limitations regarding, for instance, contamination, and complex and slow precipitation and recovery processes. Herein, we ...report the synthesis of oxygen and phosphorus-doped Graphitic carbon nitride structures (g-POCN), via a novel Zinc-catalyzed one-pot solvothermal approach, and its application in the extraction of genomic DNA (gDNA) from a vegetal matrix (P. argentatum). Experimental and molecular modeling analyses demonstrate the high affinity of gDNA with g-POCN, which provided highly efficient gDNA extraction processes, with extraction yield, as well as integrity and quality of the extracted gDNA, comparable or superior to a commercial extraction kit and isopropanol extraction. Moreover, under suitable elution conditions, this method allows the easy removal of high concentrations of gDNA from g-POCN, rendering this method as a low-cost, simple, and fast approach for the extraction of even small amounts of gDNA. Remarkably, the extracted gDNA shows no degradation, and no inhibition of the polymerase chain reaction. Therefore, g-POCN represents a promising material for the highly efficient, cost-effective, and biocompatible extraction of DNA, which could stimulate research focused on broad DNA sources, e.g., RNA extraction, plasmids, ssDNA, etc.
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