482 research outputs found

    Chemical composition, physicochemical evaluation and sensory analysis of yogurt added with extract of polyphenolic compounds from Quercus crassifolia oak bark

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    Introduction: A diet high in calories and saturated fats has been associated with health problems that have been increasing worldwide. Therefore, it is required to increase the number of formulated foods that generate well-being to health. Yogurt is a widely consumed food by all sectors of the population and it can be used as a vehicle to incorporate bioactive compounds. The phenolic compounds present in forest residues, such as those from oak bark, can be used and incorporated into yogurt, to increase its benefits as a functional food. Objective: The objective of this study was to develop a multifunctional yogurt enriched with vegetable oil (2.3% w/w) as a source of omega 6 and 3 and adding nanocapsules (24.5% w/w) of an extract of oak bark from Quercus crassifolia, rich in in phenolic compounds and high antioxidant capacity. Methods: Three yogurt formulations were prepared: F1: yogurt was made with non-fat milk, used as a control, F2: yogurt was prepared with non-fat milk and added with vegetable palm oil, and F3: non-fat yogurt was added with vegetable oil and nanoencapsulated oak bark phenolic extract. The yogurts were characterized in their chemical composition, microbiological analysis, and sensory analysis. Results: The multifunctional product F3 and product F2 presented lactic acid bacteria in concentration of 3.01X106 and 4.73x106, respectively, preserving characteristics of probiotic food. Product F3 presented low levels of syneresis (7.34%) and it was significantly different from the control yogurt (9.01%). The viscosity increased from 150 cP in the control yogurt to 341 cP in F3, due to the increase in the concentrations of solids by nanoencapsulating the phenolic. The wall material used for nanoencapsulation was sodium caseinate and mantodextrin. However, this increase in viscosity did not affect the sensory evaluation of the product. There were no significant differences between the control yogurt and the F2 and F3 products. Conclusion: A yogurt added with vegetable oil and nanoencapsulated oak bark phenolic extract was obtained. It was enhanced by the presence of probiotics, bioactive compounds, and essential fatty acids, and then evaluated and accepted by a sensory panel. Nanoencapsulation is a viable alternative to mask the characteristic astringent taste of phenolic compounds because it was not detected by the panelists

    Copper: Synthesis Techniques in Nanoscale and Powerful Application as an Antimicrobial Agent

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    Nanosized metal particles show specific physical and chemical properties that allow the creation of new composites materials, which are important for multiple applications in biology and medicine such as infections control. Metal nanoparticles, mainly copper, exhibit excellent inhibitory effect on Gram-positive and Gram-negative bacteria; therefore the exploration about the efficient, economical, and friendly environmental technics to synthesize inorganic nanoparticles is imperative. In this work a brief overview of the several methods is made including the comparison of the methods, mainly between sonochemical, microwave, and chemical routes. It allows determining the optimal parameters and technical conditions to synthesize copper nanoparticles with physical and chemical properties suitable for the oral bacterial inhibition

    Killing spectroscopy of closed timelike curves

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    We analyse the existence of closed timelike curves in spacetimes which possess an isometry. In particular we check which discrete quotients of such spaces lead to closed timelike curves. As a by-product of our analysis, we prove that the notion of existence or non-existence of closed timelike curves is a T-duality invariant notion, whenever the direction along which we apply such transformations is everywhere spacelike. Our formalism is straightforwardly applied to supersymmetric theories. We provide some new examples in the context of D-branes and generalized pp-waves.Comment: 1+35 pages, no figures; v2, new references added. Final version to appear in JHE

    Separate F-Type Plasmids Have Shaped the Evolution of the H30 Subclone of Escherichia coli Sequence Type 131.

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    The extraintestinal pathogenic Escherichia coli (ExPEC) H30 subclone of sequence type 131 (ST131-H30) has emerged abruptly as a dominant lineage of ExPEC responsible for human disease. The ST131-H30 lineage has been well described phylogenetically, yet its plasmid complement is not fully understood. Here, single-molecule, real-time sequencing was used to generate the complete plasmid sequences of ST131-H30 isolates and those belonging to other ST131 clades. Comparative analyses revealed separate F-type plasmids that have shaped the evolution of the main fluoroquinolone-resistant ST131-H30 clades. Specifically, an F1:A2:B20 plasmid is strongly associated with the H30R/C1 clade, whereas an F2:A1:B− plasmid is associated with the H30Rx/C2 clade. A series of plasmid gene losses, gains, and rearrangements involving IS26 likely led to the current plasmid complements within each ST131-H30 sublineage, which contain several overlapping gene clusters with putative functions in virulence and fitness, suggesting plasmid-mediated convergent evolution. Evidence suggests that the H30Rx/C2-associated F2:A1:B− plasmid type was present in strains ancestral to the acquisition of fluoroquinolone resistance and prior to the introduction of a multidrug resistance-encoding gene cassette harboring blaCTX-M-15. In vitro experiments indicated a host strain-independent low frequency of plasmid transfer, differential levels of plasmid stability even between closely related ST131-H30 strains, and possible epistasis for carriage of these plasmids within the H30R/Rx lineages. IMPORTANCE A clonal lineage of Escherichia coli known as ST131 has emerged as a dominating strain type causing extraintestinal infections in humans. The evolutionary history of ST131 E. coli is now well understood. However, the role of plasmids in ST131’s evolutionary history is poorly defined. This study utilized real-time, single-molecule sequencing to compare plasmids from various current and historical lineages of ST131. From this work, it was determined that a series of plasmid gains, losses, and recombinational events has led to the currently circulating plasmids of ST131 strains. These plasmids appear to have evolved to acquire similar gene clusters on multiple occasions, suggesting possible plasmid-mediated convergent evolution leading to evolutionary success. These plasmids also appear to be better suited to exist in specific strains of ST131 due to coadaptive mutations. Overall, a series of events has enabled the evolution of ST131 plasmids, possibly contributing to the lineage’s success

    Concepts in Animal Parasitology, Part 5: Ectoparasites

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    Part V: Ectoparasites, chapters 60-67, pages 732-841, in Concepts in Animal Parasitology. 2024. Scott L. Gardner and Sue Ann Gardner, editors. Zea Books, Lincoln, Nebraska, United States; part V doi: 10.32873/unl.dc.ciap075 Platyhelminthes Chapter 60: Monogenea (Class) by Griselda Pulido-Flores, pages 733-742 Chapter 61: Transversotremata (Suborder): Ectoparasitic Trematodes by Scott C. Cutmore and Thomas H. Cribb, pages 743-746 Hirudinia Chapter 62: Hirudinia (Class): Parasitic Leeches by Alejandro Oceguera-Figueroa and Sebastian Kvist, pages 747-755 Arthropoda Chapter 63: Siphonaptera (Order): Fleas by Marcela Lareschi, pages 756-770 Chapter 64: Phthiraptera (Order): Lice by Lajos Rózsa and Haylee J. Weaver, pages 771-789 Chapter 65: Triatominae (Subfamily): Kissing Bugs by numerous authors cited from open access sources, compiled by Sue Ann Gardner, pages 790-797 Chapter 66: Acari (Order): Ticks by Darci Moraes Barros-Battesti, Valeria Castilho Onofrio, and Filipe Dantas-Torres, pages 798-835 Chapter 67: Acari (Order): Mites by David Evans Walter, Gerald W. Krantz, and Evert E. Lindquist, pages 836-84

    Design Concepts of Polycarbonate-Based Intervertebral Lumbar Cages: Finite Element Analysis and Compression Testing

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    This work explores the viability of 3D printed intervertebral lumbar cages based on biocompatible polycarbonate (PC-ISO® material). Several design concepts are proposed for the generation of patient-specific intervertebral lumbar cages. The 3D printed material achieved compressive yield strength of 55 MPa under a specific combination of manufacturing parameters. The literature recommends a reference load of 4,000 N for design of intervertebral lumbar cages. Under compression testing conditions, the proposed design concepts withstand between 7,500 and 10,000 N of load before showing yielding. Although some stress concentration regions were found during analysis, the overall viability of the proposed design concepts was validated

    Fault kinematics in northern Central America and coupling along the subduction interface of the Cocos Plate, from GPS data in Chiapas (Mexico), Guatemala and El Salvador

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    International audienceNew GPS measurements in Chiapas (Mexico), Guatemala and El Salvador are used to constrain the fault kinematics in the North America (NA), Caribbean (CA) and Cocos (CO) plates triple junction area. The regional GPS velocity field is first analysed in terms of strain partitioning across the major volcano-tectonic structures, using elastic half-space modelling, then inverted through a block model. We show the dominant role of the Motagua Fault with respect to the Polochic Fault in the accommodation of the present-day deformation associated with the NA and CA relative motion. The NA/CA motion decreases from 18-22 mm yr−1 in eastern Guatemala to 14-20 mm yr−1 in central Guatemala (assuming a uniform locking depth of 14-28 km), down to a few millimetres per year in western Guatemala. As a consequence, the western tip of the CA Plate deforms internally, with ≃9 mm yr−1 of east-west extension (≃5 mm yr−1 across the Guatemala city graben alone). Up to 15 mm yr−1 of dextral motion can be accommodated across the volcanic arc in El Salvador and southeastern Guatemala. The arc seems to mark the northern boundary of an independent forearc sliver (AR), pinned to the NA plate. The inversion of the velocity field shows that a four-block (NA, CA, CO and AR) model, that combines relative block rotations with elastic deformation at the block boundaries, can account for most of the GPS observations and constrain the overall kinematics of the active structures. This regional modelling also evidences lateral variations of coupling at the CO subduction interface, with a fairly high-coupling (≃0.6) offshore Chiapas and low-coupling (≃0.25) offshore Guatemala and El Salvador

    PREVALENCIA DE Cryptosporidium parvum EN ESCOLARES DE SONORA, MEXICO

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    La criptosporidiosis es un problema de salud pública, afectando principalmente a personas inmunocomprometidas, niños y ancianos. Esta infección tiene diferentes factores causales y se le ha asociado con altas tasas de morbilidad en la población afectada. Criptosporidiosis es cosmopolita, pero su prevalencia es más alta en sociedades subdesarrollada aunque actualmente la misma se desconoce en México. El objetivo de este estudio fue determinar la prevalencia actual de Cryptosporidium parvum (C. parvum) en una subpoblación de escolares del municipio de Hermosillo, Sonora, México. Se usó ELISA para detectar antígenos fecales de C. parvum. Se invitó a participar a 720 escolares registrados oficialmente en tres primarias públicas. 175 niñas y 145 niños, de edades entre 6 a 13 años participaron voluntariamente durante septiembre a diciembre 2008. De los 320 escolares estudiados, 121 (37,8 %) mostraron infección por C. parvum. No se encontró diferencia en la prevalencia de criptosporidiosis entre sexos (p = 0,15), ni entre áreas suburbana y rural (p = 0,18). Se observó un aumento de la infección con la edad en este estudio. Criptosporidiosis quizá es un serio problema de salud pública en el estado de Sonora y se requieren estudios adicionales que lo confirmen para que las autoridades responsables puedan prevenir y controlar la infección
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