ABSTRACT
In this article, we propose a simple photochemical method to synthesize pure La2Ti2O7 films and La2Ti2O7 films doped with silver at 1.0, 3.0, and 5.0 mol%. After annealing the photo-deposited films at 900 °C, XRD, SEM, and XPS analyses showed the formation of a monoclinic La2Ti2O7 phase and the presence of Ag and AgO in doped samples. Photocatalytic tests for Congo red degradation demonstrated that pure La2Ti2O7 achieved 25.4% degradation, while doped samples reached a maximum of 92.7% degradation. Moreover, increasing silver doping on La2Ti2O7 films significantly reduced the growth of Staphylococcus aureus, indicating potential antibacterial properties. The enhanced photoactivity was attributed to the formation of a type I heterojunction between La2Ti2O7 and AgO, and a degradation mechanism was proposed based on Congo red degradation.
Subject(s)
Congo Red , Staphylococcus aureus , Congo Red/chemistry , Silver/pharmacology , Silver/chemistry , Titanium/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistryABSTRACT
The medical treatment of laxoscelisms is based solely on supportive measures. Although equine antiserum for Sphingomyelinase C (SMASE) and D isomers are available, it is not used due to the risk of an anaphylactic reaction and its unproven efficacy. As potential enzyme inhibitors, derivatives of Iron chitosan complexes were studied (Shiff base having -R = -H, -Cl, -Br, -F, -OCH3, -CH3, -NO2). These chitosan complexes were chosen because they have revealed good results in medicine and catalysis due to their biodegradable characteristics and bioavailability. Besides considering that these complexes have not been studied in relation to this toxin. The mechanisms underlying the catalytic and catcher effects of Iron chitosan complexes were studied using electrochemistry, UV-Vis spectroscopy and microscopic assay at physiological pH. The electrochemical studies showed that one of seven Schiff bases of chitosan adsorbed on glassy carbon electrode was electrocatalytically active for the oxidation of sphingomyelinase at 1.27 V, and that allowed proposing a reaction scheme for SMASE oxidation by adsorbed Iron complexes. On the other hand, even though the spectroscopic studies indicated that there was no chemical bond formation between the complex and SMASE in solution, the microscopic studies showed that this complex proved to be a remarkable cellular protector in presence of the enzyme. In conclusion, Shiff base of chitosan with R = -CH3 was the only active complex in front of sphingomyelinase C, protecting red blood cells, according to our electrochemical and microscopic studies.
Subject(s)
Chitosan/chemistry , Coordination Complexes/metabolism , Iron/chemistry , Schiff Bases/chemistry , Sphingomyelin Phosphodiesterase/metabolism , Adsorption , Biocatalysis , Carbon/chemistry , Coordination Complexes/chemistry , Electrochemical Techniques , Electrodes , Erythrocytes/cytology , Erythrocytes/drug effects , Erythrocytes/metabolism , Humans , Oxidation-Reduction , Spectrophotometry, Ultraviolet , Sphingomyelin Phosphodiesterase/antagonists & inhibitorsABSTRACT
La deficiencia de zinc afecta aproximadamente un tercio de la población mundial, principalmente en los países en vía de desarrollo, en las áreas rurales y en las comunidades más pobres, donde constituye un importante factor de riesgo asociado a enfermedad. En este trabajo se realiza una revisión de los avances científicos que han permitido conocer el papel fundamental del zinc en el control de la neurogénesis, el funcionamiento del cerebro y el desarrollo cognitivo. Con el fin de generar en los profesionales de salud, interés por la investigación de los efectos de la deficiencia de zinc en el desarrollo neurológico y cognitivo y su impacto negativo en el desarrollo cultural, social y económico de los pueblos(AU)
The zinc deficiency affects approximately a third of the world population, principally in the developing countries, the rural areas and in the poorest communities, where this micronutrient deficiency is one of the most prevalent risk factor for nutrientrelated diseases. This paper compiles scientific advances about the key role of the essential trace element zinc in the neurogenesis control, brain function and cognitive development. The aim of this work is to generate in health professionals, interest about the zinc deficiency effects in neuro-intellectual development and its negative impact in the cultural, economic and social development of the countries(AU)
Subject(s)
Humans , Male , Female , Micronutrients/administration & dosage , Dwarfism/etiology , Zinc Deficiency , Failure to Thrive/etiology , Trace Elements , Acrodermatitis , Cognition Disorders , Developing CountriesABSTRACT
The zinc deficiency affects approximately a third of the world population, principally in the developing countries, the rural areas and in the poorest communities, where this micronutrient deficiency is one of the most prevalent risk factor for nutrientrelated diseases. This paper compiles scientific advances about the key role of the essential trace element zinc in the neurogenesis control, brain function and cognitive development. The aim of this work is to generate in health professionals, interest about the zinc deficiency effects in neuro-intellectual development and its negative impact in the cultural, economic and social development of the countries.
Subject(s)
Central Nervous System/drug effects , Child Development/drug effects , Cognition Disorders/etiology , Cognition/drug effects , Global Health , Zinc/deficiency , Central Nervous System/physiopathology , Child Development/physiology , Child, Preschool , Cognition/physiology , Cognition Disorders/physiopathology , Cognition Disorders/prevention & control , Humans , Zinc/administration & dosageABSTRACT
The exopolysaccharide (EPS) separated from the entomopathogenic fungus Metarhizium anisopliae was determined by gel permeation chromatography to be homogeneous. The high-performance anion-exchange chromatography with pulsed-amperometric detection (HPAE-PAD) showed a content of monosaccharides D-galactosamine and D-fucose at a molar ratio of about 2:1. The results obtained from Fourier transform-infrared spectroscopy (FT-IR) and second derivative FT-IR spectrum confirmed the proposed structure.
El exopolisacárido (EPS) separado desde el hongo entomopatogénico Metarhizium anisopliae determinado por cromatografía de exclusión en gel ser homogéneo. La cromatografía iónica de alto rendimiento con detección de pulso amperométrico (HPAE-PAD) mostró un contenido de monosacáridos D-galactosamina y D-fucosa en una relación molar de alrededor de 2:1. Los resultados obtenidos desde la espectroscopía infrarroja con transformada de Fourier (FT-IR) y la segunda derivada del espectro FT-IR confirmaron la estructura propuesta.
Subject(s)
Metarhizium , Fungal Polysaccharides/analysis , Chromatography, Ion Exchange , Spectroscopy, Fourier Transform InfraredABSTRACT
This study reports the antibacterial activity of an oligosaccharide, prepared by partial acid hydrolysis of a native Paecilomyces sp. exopolysaccharide, and of its aminoglycosylated derivative, prepared by reductive alkylation of the oligosaccharide, against E. coli and S. aureus.
Subject(s)
Anti-Bacterial Agents/pharmacology , Oligosaccharides/pharmacology , Paecilomyces/chemistry , Anti-Bacterial Agents/chemistry , Chromatography, Gel , Glycosylation , Microbial Sensitivity Tests , Oligosaccharides/chemistry , Spectroscopy, Fourier Transform InfraredABSTRACT
Chitin and chitosan are a class of metabolites that occurring in some fungi species that are associated with commercial and medicinal plants, this is in Mucor sp. for example with an ample number of biological activities, being antibacterial and antifungal one of the most important. Into our program of search of biopesticides and natural compounds with biological activities, we have studying chitosan that was obtained from the culture medium of the fungus Mucor ruoxii. Chitooligosaccharides were prepared by partial acid hydrolysis of native chitosan and an aminoglycosylated derivative was obtained by reductive amination of the chitooligosaccaride. The solubilities of these compounds were measured at different pHs and its antibacterial activity against Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive). Chitosan and the derivatives tested exhibited a good antibacterial activity against S. aureus.
Quitina y quitosano son una clase de metabolitos que producen algunas especies de hongos que están asociados con plantas medicinales y comerciales, esto es por ejemplo en Mucor sp., con un amplio número de actividades biológicas, siendo la antibacteriana y antifúngica unas de las más importantes. En nuestro programa de investigación de biopesticidas y compuestos naturales, estamos estudiando quitosano obtenido de el medio de cultivo del hongo Mucor ruoxii. Quitooligosacáridos fueron preparados por hidrólisis parcial ácida de quitosano nativo y un derivado aminoglicosilado fue obtenido por aminación reductiva del quitooligosacárido. Las solubilidades de estos compuestos fueron medidas a diferentes pHs y su actividad antibacteriana frente a Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive). Quitosano y los derivados testeados exhiben una buena actividad antibacteriana frente a S. aureus.
Subject(s)
Anti-Bacterial Agents/pharmacology , Escherichia coli , Mucor/chemistry , Oligosaccharides/pharmacology , Chitosan/pharmacology , Staphylococcus aureus , Chromatography, Gel , Hydrogen-Ion Concentration , Hydrolysis , Solubility , Spectrum AnalysisABSTRACT
The aim of this study was to investigate the antibacterial activity of chitooligosaccharide, prepared by partial acid hydrolysis of chitosan, and of an aminoglycosylated derivative, prepared by reductive alkylation of the chitooligosaccharide, against E. coli and S. aureus.
Subject(s)
Anti-Bacterial Agents/pharmacology , Chitin/pharmacology , Chitosan/pharmacology , Escherichia coli/drug effects , Oligosaccharides/pharmacology , Plant Lectins/pharmacology , Staphylococcus aureus/drug effects , Chitosan/chemistry , Glucosamine/chemistry , Hydrolysis , Microbial Sensitivity Tests , Models, Molecular , Oligosaccharides/chemistry , Spectroscopy, Fourier Transform InfraredABSTRACT
In this work we discuss different approaches for achieving electrodes modified with N(4) macrocyclic complexes for the catalysis of the electrochemical oxidation of thiols. These approaches involve adsorption, electropolymerization and molecular anchoring using self assembled monolayers. We also discuss the parameters that determine the reactivity of these complexes. Catalytic activity is associated with the nature of the central metal, redox potentials and Hammett parameters of substituents on the ligand. Correlations between catalytic activity (log i at constant E) and the redox potential of catalysts for complexes of Cr, Mn, Fe, Co, Ni and Cu are linear with an increase of activity for more positive redox potentials. For a great variety complexes bearing the same metal center (Co) correlations between log i and E(o') of the Co(II)/Co(I) couple have the shape of an unsymmetric volcano. This indicates that the potential of the Co(II)/Co(I) couple can be tuned using the appropriate ligand to achieve maximum catalytic activity. Maximum activity probably corresponds to a DeltaG of adsorption of the thiol on the Co center equal to zero, and to a coverage of active sites by the thiol equal to 0.5.
Subject(s)
Indoles/chemistry , Metalloporphyrins/chemistry , Sulfhydryl Compounds/chemistry , Catalysis , Electrochemistry , Electrodes , Isoindoles , Macromolecular Substances/chemistry , Molecular Structure , Oxidation-Reduction , Surface PropertiesABSTRACT
Este trabajo se realizó con el fin de obtener pulpa congelada de maracuyá y con ella un nectar dietético con edulcorado con aspartame y con un buen contenido nutricional a base de suero de leche y pulpa de maracuyá y se evaluó su estabilidad. Se elaboró un nectar fortificado estabilizado con metabisulfito. Se estudió el comportamiento y se hizo el control de calidad de los nectares y de la pulpa desde el punto de vista sensorial, fisicoquímico y microbiológico. Se obtuvo un producto dietético con un buen contenido nutricional, un buen grado de aceptación y un tiempo de vida de cuatro semanas para el nectar dietético y fortificado de maracuyá sin metabisulfito y de seis semanas pára el nectar dietético y fortificado estabilizado con metabisulfito
