Two Roads Converging: Mitochondria and Inflammatory Signaling

As the complexity of cellular signaling in inflammatory response emerges, it is increasingly clear that mitochondria are directly involved in, and in some cases are even required for, activation of inflammatory response. As a bioenergetic organellar network, mitochondria dynamically modulate their organization and function in response to cellular signaling cues and metabolic demand. The NLRP3 inflammasome, a caspase-activating multifactor scaffolding assembly, is directly activated by mitochondrial factors and functional parameters. Mitochondria are also heavily implicated as downstream targets of inflammation in a variety of tissues. Elevated inflammation and cytokine-mediated damage to mitochondria are implicated in the pathogenesis of disparate conditions such as Type 2 diabetes and autism spectrum disorders. Recent findings indicate that mitochondrial factors are released as extracellular mediators of inflammatory response. Here, we discuss the mechanistic interaction of mitochondria in inflammatory signaling, as well as the implications for inflammatory mitochondrial damage as a causative force in highly prevalent human diseases

Análisis de los riesgos que pueden generar las firmas transnacionales de auditoría ante la institución de la Revisoría Fiscal en un contexto nacional de implementación de normas internacionales.

En Colombia se ha implementado desde 1990 el modelo económico del libre comercio y la financiarización siguiendo una estrategia neoliberal. En el marco de ese modelo agenciado por las organizaciones que componen la Arquitectura Financiera Internacional se propone la modificación a las funciones y demás características intrínsecas de la institución privada auxiliar de control del Estado: la Revisoría Fiscal. Utilizando una metodología de tipo descriptivo, con un enfoque principalmente cualitativo y un método inductivo-deductivo, se analizó la historia de la Institución y su caracterización, además de los intereses y las organizaciones de la Arquitectura Financiera Internacional que apalancan la consolidación de los estándares internacionales de Contabilidad y Auditoría, así como el nivel de la concentración del mercado en las BIG4 y sus posibles causas, lo anterior para determinar el impacto que tienen en la Revisoría Fiscal. Concluyendo que los estándares internacionales contribuyen desde las construcciones de información financiera y la laxitud del control al apalancamiento del modelo económico y político imperante a la par de facilitar la concentración del mercado por parte de las BIG4; y es por ello que se proponen modificar las funciones, principios, técnicas y alcance de la Revisoría Fiscal, contenidas en el Código de Comercio entre otras normas, para equipararlas a las de la auditoría afectando con ello el control y la confianza pública.PregradoCONTADOR(A) PÚBLIC

Fabrication and Characterization of Centrifugally Spun Poly(acrylic acid) Nanofibers

The production of poly(acrylic acid) (PAA) nanofibers by the centrifugal spinning of PAA solutions in water is reported. The effect of the spinneret rotational speed and concentration of PAA solutions on the diameter of nanofibers and on their quality (assessed by the absence of beads) is discussed. The main physical properties of PAA such as glass-transition temperature (Tg) are studied in detail and compared to the feature of the as-received homopolymer. It is shown that the glass-transition temperature of the bulk PAA and PAA nanofibers (as measured by differential scanning calorimetry) depends on the heating rate according to a Williams–Landel–Ferry-like equation. Raman spectroscopy data provided additional information about the differences between the as-received polymer and the nanofibers. Preliminary results on antibacterial properties of the PAA nanofibers are reported

Texas Sour Orange Juice Used in Scaffolds for Tissue Engineering

Fine fibers of polyhydroxybutyrate (PHB), a biopolymer, were developed via a centrifugal spinning technique. The developed fibers have an average diameter of 1.8 µm. Texas sour orange juice (SOJ) was applied as a natural antibacterial agent and infiltrated within the fibrous membranes. The antibacterial activity against common Gram-positive and Gram-negative bacteria (Staphylococcus aureus and Escherichia coli, respectively) was evaluated as well as cell adhesion and viability. The PHB/SOJ scaffolds showed antibacterial activity of up to 152% and 71% against S. aureus and E. coli, respectively. The cell studies revealed a suitable environment for cell growth and cell attachment. The outcome of this study opens up new opportunities for fabrication of fibrous materials for biomedical applications having multifunctional properties while using natural agents

Fabrication of cellulose fine fiber based membranes embedded with silver nanoparticles via Forcespinning

This study presents the successful development of cellulose fiber based membranes embedded with silver nanoparticles. These fine fiber membranes were developed utilizing the Forcespinning (FS) technique followed by alkaline hydrolysis treatment. The fiber morphology, homogeneity and yield were optimized by varying spinning parameters such as polymer concentration and angular velocity of the spinnerets. The structure, thermal and mechanical properties, and water absorption capability of the developed membranes were investigated. The cellulose acetate (CA) present in the membrane was converted to cellulose in the presence of embedded silver nanoparticles by alkaline hydrolysis. The silver nanoparticles embedded cellulose membrane exhibits outstanding water absorption capacity with fast uptake rate. Its high porosity, three-dimensional network structure with wellinterconnected pores, as well as the intrinsically highly hydrophilic nature of cellulose material greatly favor its potential application as wound dressings. The antimicrobial activity was evaluated by the disk diffusion method. The composite membranes exhibit excellent antimicrobial activity against Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa, and Gram-positive Staphylococcus aureus, owing to the slow and sustained release of embedded silver nanoparticles

Forcespun polyvinylpyrrolidone/copper and polyethylene oxide/copper composite fibers and their use as antibacterial agents

Copper nanoparticles (CuNPs) embedded in polyvinylpyrrolidone (PVP) and polyethylene oxide (PEO) fiber-matrices were prepared through centrifugal spinning of PVP/ethanol and PEO/aqueous solutions, respectively. The prime focus of the current study is to investigate the antibacterial activity of composite fibers against Escherichia coli (E. coli) and Bacillus cereus (B. cereus) bacteria. During the fiber formation, the centrifugal spinning parameters such as spinneret rotational speed, spinneret to collector distance, and relative humidity were carefully chosen to obtain long and continuous fibers. The structural and morphological analyses of both composite fibers were investigated using scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and thermogravimetric analysis. In the antibacterial test, PVP/Cu and PEO/Cu composite fibrous membranes exhibited inhibition efficiency of 99.98% and 99.99% against E. coli and B. cereus bacteria, respectively. Basically, CuNPs were well embedded in the fibrous membrane at the nanoscale level, which facilitated the inhibition of bacterial functions through the inactivation of the chemical structure of the cells. Such an effective antibacterial agent obtained from forcespun composite fibers could be promising candidates for biomedical applications

Development of antimicrobial chitosan based nanofiber dressings for wound healing applications

Objective(s): Chitosan based composite fine fibers were successfully produced via a centrifugal spinning technology. This study evaluates the ability of the composites to function as scaffolds for cell growth while maintaining an antibacterial activity. Materials and Methods: Two sets of chitosan fiber composites were prepared, one filled with anti-microbial silver nanoparticles and another one with cinnamaldeyhde. Chitosan powder was dissolved in trifluoroacetic acid and dichloromethane followed by addition of the fillers. The fiber output was optimized by configuring the polymer weight concentration (7, 8, and 9 w/w% chitosan) and applied angular velocity (6000-9000 RPM) within the spinning process. Results: Scanning electron microscopy revealed fiber diameters ranging from 800-1500 nm. Cinnamaldehyde and silver nanoparticles helped to improve and control the anti-bacterial activity. Through a verified cell counting method and disk diffusion method, it was proven that the chitosan based composite fibers possess an enhanced anti-bacterial/microbial activity against gram-positive Staphylococcus aureus. Both composite systems showed anti-bacterial activity, inhibition zones fluctuating between 5 to 10 mm were observed depending on the size of the fiber mat and no bacteria was found within the mats. The developed fiber scaffolds were found to be noncytotoxic serving as effective three-dimensional substrates for cell adhesion and viability. Conclusion: These results provide potential to use these scaffolds in wound healing and tissue regeneration applications

Texas Sour Orange Juice Used in Scaffolds for Tissue Engineering

Fine fibers of polyhydroxybutyrate (PHB), a biopolymer, were developed via a centrifugal spinning technique. The developed fibers have an average diameter of 1.8 µm. Texas sour orange juice (SOJ) was applied as a natural antibacterial agent and infiltrated within the fibrous membranes. The antibacterial activity against common Gram-positive and Gram-negative bacteria (Staphylococcus aureus and Escherichia coli, respectively) was evaluated as well as cell adhesion and viability. The PHB/SOJ scaffolds showed antibacterial activity of up to 152% and 71% against S. aureus and E. coli, respectively. The cell studies revealed a suitable environment for cell growth and cell attachment. The outcome of this study opens up new opportunities for fabrication of fibrous materials for biomedical applications having multifunctional properties while using natural agents