•An inclusion complex of 2-nonanone with β-cyclodextrin was prepared.•Different analysis confirmed the formation of inclusion complexes.•The active compound 2-nonanone is fungistatic to Botrytis ...cinerea.
An important issue in food technology is that antimicrobial compounds can be used for various applications, such as the development of antimicrobial active packaging materials. Yet most antimicrobial compounds are volatile and require protection. In the present study, the inclusion complexes of 2-nonanone (2-NN) with β-cyclodextrin (β-CD), were prepared by a co-precipitation method. Entrapment efficiency (EE), thermal analysis (DSC and TGA), X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FT-IR), sorption isotherms and antifungal activity were evaluated for the characterization of the inclusion complex (β-CD:2-NN). A higher EE was obtained (34.8%) for the inclusion complex 1:0.5 than for other molar rates. Both DSC and TGA of the inclusion complexes showed the presence of endothermic peaks between 80°C and 150°C, attributed to a complexation phenomenon. Antimicrobial tests for mycelial growth reduction under atmospheric conditions proved the fungistatic behaviour of the inclusion complexes against Botrytis cinerea.
Mixotrophic cultivation of microalgae provides a very promising alternative for producing carbohydrate-rich biomass to convert into bioethanol and value-added biocompounds, such as vitamins, ...pigments, proteins, lipids and antioxidant compounds. Spirulina platensis may present high yields of biomass and carbohydrates when it is grown under mixotrophic conditions using cheese whey. However, there are no previous studies evaluating the influence of this culture system on the profile of fatty acids or antioxidant compounds of this species, which are extremely important for food and pharmaceutical applications and would add value to the cultivation process. S. platensis presented higher specific growth rates, biomass productivity and carbohydrate content under mixotrophic conditions; however, the antioxidant capacity and the protein and lipid content were lower than that of the autotrophic culture. The maximum biomass yield was 2.98 ±0.07 g/L in growth medium with 5.0% whey. The phenolic compound concentration was the same for the biomass obtained under autotrophic and mixotrophic conditions with 2.5% and 5.0% whey. The phenolic compound concentrations showed no significant differences except for that in the growth medium with 10.0% whey, which presented an average value of 22.37±0.14 mg gallic acid/g. Mixotrophic cultivation of S. platensis using whey can be considered a viable alternative to reduce the costs of producing S. platensis biomass and carbohydrates, shorten cultivation time and produce carbohydrates, as it does not require adding expensive chemical nutrients to the growth medium and also takes advantage of cheese whey, an adverse dairy industry byproduct.
The objective of this study was to characterize the chemical composition and lipid profile of colostrum and milk of purebred Quarter Horse mares. Thirty-four (34) purebred mares were selected, which ...were then separated into groups according to age, birth order and lactation stage. Colostrum samples were collected in the first six hours after delivery and milk samples from the 7.sup.th postpartum day, with intervals of 14 days until the end of lactation. The samples were refrigerated and sent to the Milk Laboratory of the University (Laboleite-UFRN), where they were analyzed for chemical composition. Colostrum was assessed by refractometry. The lipid profile was determined by gas chromatography through a separation of methyl esters. The data were tabulated and subjected to descriptive statistics and analysis of variance by the F-Test, and the groups were compared by the Tukey test using a significance level of 5%. There was high protein content and reduced lactose content for the colostrum of the Quarter Horse mares, differing from other breeds. The milk composition was not influenced by the mares' age. However, variations in the lactation stage and in the birth order of the Quarter Horse mares altered the milk's chemical composition. There is variation in the lipid composition of milk according to the lactation stage, without changing the characteristic profile of the mares' milk or diminishing the nutritional quality of the lipid fraction.
Scientific collaboration networks are a hallmark of contemporary academic research. Researchers are no longer independent players, but members of teams that bring together complementary skills and ...multidisciplinary approaches around common goals. Social network analysis and co-authorship networks are increasingly used as powerful tools to assess collaboration trends and to identify leading scientists and organizations. The analysis reveals the social structure of the networks by identifying actors and their connections. This article reviews the method and potential applications of co-authorship network analysis in health. The basic steps for conducting co-authorship studies in health research are described and common network metrics are presented. The application of the method is exemplified by an overview of the global research network for Chikungunya virus vaccines.
The present work aimed to study different parts of colored cotton waste through energetic characterization and analytical flash pyrolysis. Stalks and bolls of BRS cotton cultivars from Sementes do ...Brasil (Green, Ruby, Topaz and Jade) were studied, using white cotton (BRS 286) as a comparison. The energetic potential of biomass was evaluated by bulk density, High Heating Value (HHV), proximate and ultimate analysis, compositional and thermogravimetric analysis (TGA). Pyrolysis was performed in a micro-pyrolyzer and the products were identified by gas chromatography and mass spectroscopy (Py-GC/MS). The results indicated a significant energetic potential, suggesting that can be used as an alternative energy source for thermochemical processes. The results of conventional pyrolysis indicated the presence of oxygenated compounds of different organic groups: aldehydes, ketones, phenols, furans and ethers, characteristic of the decomposition of lignocellulosic materials. Light organic acids in the C1-C4 range stood out the most, followed by phenols that appeared in a considerable proportion. Finally, it is concluded that the energy potential and pyrolysis products of the different parts (stalks and bolls) of colored cotton waste can be used to generate bioenergy and various chemical compounds of plant origin from green chemistry.
Biofilm-associated diseases are one of the main causes of implant failure. Currently, the development of implant surface treatment goes beyond the osseointegration process and focuses on the creation ...of surfaces with antimicrobial action and with the possibility to be re-activated (i.e., light source activation). Titanium dioxide (TiO2), an excellent photocatalyst used for photocatalytic antibacterial applications, could be a great alternative, but its efficiency is limited to the ultraviolet (UV) range of the electromagnetic spectrum. Since UV radiation has carcinogenic potential, we created a functional TiO2 coating codoped with nitrogen and bismuth via the plasma electrolytic oxidation (PEO) of titanium to achieve an antibacterial effect under visible light with re-activation potential. A complex surface topography was demonstrated by scanning electron microscopy and three-dimensional confocal laser scanning microscopy. Additionally, PEO-treated surfaces showed greater hydrophilicity and albumin adsorption compared to control, untreated titanium. Bismuth incorporation shifted the band gap of TiO2 to the visible region and facilitated higher degradation of methyl orange (MO) in the dark, with a greater reduction in the concentration of MO after visible-light irradiation even after 72 h of aging. These results were consistent with the in vitro antibacterial effect, where samples with nitrogen and bismuth in their composition showed the greatest bacterial reduction after 24 h of dual-species biofilm formation (Streptococcus sanguinis and Actinomyces naeslundii) in darkness with a superior effect at 30 min of visible-light irradiation. In addition, such a coating presents reusable photocatalytic potential and good biocompatibility by presenting a noncytotoxicity effect on human gingival fibroblast cells. Therefore, nitrogen and bismuth incorporation into TiO2 via PEO can be considered a promising alternative for dental implant application with antibacterial properties in darkness, with a stronger effect after visible-light application.
Microalgae are autotrophs and CO.sub.2 fixers with great potential to produce biofuels in a sustainable way, however the high cost of biomass production is a challenge. Mixotrophic growth of ...microalgae has been presented as a great alternative to achieve economic sustainability. Thus, the present work reports the energetic characterization of S. platensis biomasses cultivated under autotrophic (A) and mixotrophic conditions using cheese whey waste at different concentrations, 2.5 (M2.5), 5.0 (M5) and 10.0% (M10), in order to analyze the potential production of valuable chemicals and bio-oil by TGA/DTG and Py-GC/MS. The biochemical compositions of the studied biomasses were different due to the influence of different culture mediums. As the whey concentration increased, there was an increase in the carbohydrate content and a decrease in the protein content, which influenced the elemental composition, calorific value, TGA and volatile compounds evaluated by Py-GC/MS at 450°C, 550°C and 650°C. Sample M10 had lower protein content and formed a smaller amount of nitrogenates compounds by pyrolysis at all temperatures evaluated. There was a reduction of 43.8% (450º), 45.6% (550ºC) and 23.8% (650ºC) in the formation of nitrogenates compounds in relation to sample A. Moreover, the temperature also showed a considerable effect in the formation of volatile compounds. The highest yields of nitrogenates compounds, phenols and aromatic and non-aromatic hydrocarbons were observed at 650ºC. The oxygenated, and N and O containing compounds decreased as the temperature increased. Hydrocarbons such as toluene, heptadecane and heneicosane were produced by S.platensis pyrolysis, which makes this biomass attractive for production of high quality bio-oil and valuable chemicals. Therefore, the results showed that it is possible to decrease the formation of nitrogen compounds via manipulation of growth conditions and temperature.
Polymicrobial infection is the main cause of dental implant failure. Although numerous studies have reported the ability of titanium (Ti) surface modifications to inhibit microbial adhesion and ...biofilm accumulation, the majority of solutions for the utilization of Ti antibacterial surfaces have been testedin in vitro and animal models, with only a few developed surfaces progressing into clinical research. Motivated by this huge gap, we critically reviewed the scientific literature on the existing antibacterial Ti surfaces to help understand these surfaces' impact on the “puzzle” of undesirable dental implant-related infections. This manuscript comprises three main sections: (i) a narrative review on topics related to oral biofilm formation, bacterial-implant surface interactions, and on how implant-surface modifications can influence microbial accumulation; (ii) a critical evidence-based review to summarize pre-clinical and clinical studies in an attempt to “fit pieces into the puzzle” to unveil the best way to reduce microbial loads and control polymicrobial infection around dental implants showed by the current in vivo evidence; and (iii) discussion and recommendations for future research testing emerging antibacterial implant surfaces, connecting basic science and the requirements for future clinical translation. The findings of the present review suggest no consensus regarding the best available Ti surface to reduce bacterial colonization on dental implants. Smart release or on-demand activation surface coatings are a “new piece of the puzzle”, which may be the most effective alternative for reducing microbial colonization on Ti surfaces, and future studies should focus on these technologies.
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•The role of titanium surface modifications on bacterial accumulation was critically reviewed.•No consensus was revealed on the best available surface to prevent dental implant contamination.•Pre-clinical and clinical research on clinically relevant oral bacteria is scarce.•Smart release or on-demand activation coatings may provide solutions for the “puzzle” issues.
En este trabajo se diseñó una intervención para contribuir a la formación de científicos, a través de rediseñar la evaluación de una tarea de desempeño auténtica. Para ello, se creó y validó una ...rúbrica analítica para evaluar un informe de laboratorio en formato publicación científica en la asignatura bioquímica. Se obtuvo un consenso entre evaluadores de 70%. El análisis permitió mejorar el instrumento e identificar debilidades en el desempeño de los estudiantes. Se obtuvo la percepción de los estudiantes de la experiencia, quienes declararon utilizar la rúbrica, apreciándose acuerdo respecto a su calidad, objetividad y pertinencia. Sin embargo, no hubo acuerdo respecto de la utilidad para guiar y retroalimentar, ni hubo efecto en el rendimiento, evidenciando que se requiere robustecer el diseño. En consecuencia, se generó una propuesta que incorpora: involucrar a los estudiantes en la definición de estándares de calidad, guiar el análisis de datos, incluir coevaluación y retroalimentación.
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