Characterization and optimization of polymer-polymer aqueous two-phase systems for the isolation and purification of CaCo2 cell-derived exosomes

Exosomes are cell-derived vesicles that present attractive characteristics such as nano size and unique structure for their use as drug delivery systems for drug therapy, biomarkers for prognostic, diagnostic and personalized treatments. So far, one of the major challenges for therapeutic applications of exosomes is the development of optimized isolation methods. In this context, aqueous two-phase systems (ATPS) have been used as an alternative method to isolate biological molecules and particles with promising expectations for exosomes. In this work, fractionation of exosomes obtained from CaCo2 cell line and culture media contaminants were individually performed in 20 polymer-polymer ATPS. The effect of design parameters such as polymer composition, molecular weight, and tie-line length (TLL) on polyethylene glycol (PEG)-Dextran, Dextran-Ficoll and PEG-Ficoll systems was studied. After partition analysis, 4 of the 20 systems presented the best exosome fractionation from contaminants under initial conditions, which were optimized via salt addition (NaCl) to a final concentration of 25 mM, to improve collection efficiency. The PEG 10,000 gmol-1 –Dextran 10,000 gmol-1 system at TLL 25% w/w with NaCl, showed the best potential isolation efficiency. Following this proposed strategy, an exosome purification factor of 2 in the top PEG-rich phase can be expected furtherly demonstrating that ATPS have the potential for the selective recovery of these promising nanovesicles

Effect of fermented, hardened, and dehulled of chickpea (Cicer arietinum) meals in digestibility and antinutrients in diets for tilapia (Oreochromis niloticus)

Among the most typical feed sources for tilapia, plants represent a low-cost source in substituting for traditional high-cost feed ingredients. Fermentation, hardening and dehulling are common grains processing techniques to make plant nutrients available and more digestible to fish. Apparent digestibility coefficients (ADC) of dry matter and protein, and antinutrients (phytic acid and tannins) in fermented, hardened and dehulled chickpea (Cicer arietinum) meals were determined for juvenile Nile tilapia (Oreochromis niloticus). The highest ADC was obtained with processed (fermented, hardened and dehulled) chickpea meals compared with non-processed. Results indicated that fermentation increased the protein content by 13.1%, decreased the content of ash and phytic acid (47.5 and 45%, respectively), and increased the ingredient apparent digestibility of dry matter (ADM) by 23.2%, and the ingredient apparent digestibility of protein (ADP) by 41.9%. Dehulling meal increased the protein (5.7%) and lipid (6.4%) content of chickpea grains; decreased fiber, ash and tannin content (75.3%, 19.1%, and 84.5%, respectively); and increased ADM by 12.8%, and ADP by 10.4%. We conclude that fermented, hardened and dehulled chickpea meals represent a potential alternative in diets for juvenile O. niloticus

Volcano Popocatepetl, Mexico: ULF geomagnetic anomalies observed at Tlamacas station during March?July, 2005

International audienceIn this paper the first results of ULF (Ultra Low Frequency) geomagnetic anomalies observed at Tlamacas station (Long. 261.37, Lat. 19.07) located at 4 km near the volcano Popocatepetl (active volcano, Long. 261.37, Lat. 19.02) for the period March?July, 2005 and their analysis are presented. The geomagnetic data were collected with a 3-axial fluxgate magnetometer designed at UCLA (University of California, Los Angeles, 1 Hz sampling rate frequency, GPS). Our analysis reveals some anomalies which are suspected to be generated by local volcanic origin: the EM background in the vicinity of the volcano is significantly noisier than in other reference stations; the sporadic strong noise-like geomagnetic activity observed in the H-component; locally generated geomagnetic pulsations (without preferred polarization) are detected only at Tlamacas station

Ultrasound-Assisted Melt Extrusion of Polymer Nanocomposites

A review of the latest developments in ultrasound-assisted melt extrusion of polymer nanocomposites is presented. In general, the application of ultrasound waves during melt extrusion of polymer in the presence of nanoparticles results in a more homogeneous dispersion of the nanoparticles in the polymer matrix. In spite of this, a lack of understanding in the field has hindered the development of this processing technique. Based on the analysis of literature on the field, key aspects are identified for a better understanding of the physical and chemical effects of ultrasound waves and the fabrication of polymer nanocomposites by means of melt extrusion

Bacteriophage Therapy: An Alternative for the Treatment of Staphylococcus aureus Infections in Animals and Animal Models

Staphylococcus aureus causes hospital-acquired (HA), community-acquired (CA) and companion animal and livestock-associated (LA) infections. Molecular epidemiology studies suggest that although host specificity may be associated with specific genetic lineages, recent human-to-animal and animal-to-human transmissions related to mobile genetic elements have been described. Gene transfers include virulence and antibiotic resistance genes, thus making it difficult to control multidrug resistance S. aureus infections. Bacteriophages (phages) and endolysins, the enzymes responsible for bacterial lysis by phages, are alternatives to the use of antibiotics for the control of S. aureus infections. In this work, we review current advances in the development of phage therapy and the study and design of recombinant endolysins to treat S. aureus infections. Preliminary results of bacteriophage isolation based on molecular epidemiology knowledge show that bacteriophages are specific of genetic lineages and that this strategy may be used as an approach to isolate and evaluate new bacteriophages for therapy

ESTUDIO DE UNA ANTENA DE MICROCINTA FRACTAL TIPO E PARA LA BANDA DE LOS 2.4 GHZ

ResumenEn este trabajo, se presenta el estudio experimental y por simulación de una antena de parche basada en la geometría fractal tipo E para operar en la banda libre de los 2.4 GHz. La estructura electromagnética de la antena diseñada se analiza utilizando el simulador HFSS de ANSI, mientras que el prototipo experimental se caracteriza utilizando un analizador de redes de 6.5 GHz acoplado a un equipo de medición de campo cercano para medir los parámetros importantes de esta antena. Considerando la geometría fractal tipo E de dos iteraciones, los resultados en las simulaciones muestran que la antena diseñada presenta una frecuencia de resonancia de 2.463 GHz con pérdidas por retorno cercanas a -50 dB y un ancho de banda de acoplamiento de 74 MHz. Los parámetros correspondientes en el prototipo experimental resultaron ser de 2.624 GHz, -17 dB y 100 MHz, respectivamente. Estos resultados demuestran la factibilidad de utilizar la antena de microcinta fractal tipo E para aplicaciones en las comunicaciones inalámbricas para la banda de los 2.4 GHz.Palabras Claves: ancho de banda de acoplamiento, antenas de banda ancha, antenas de microcinta, bandas sin licencia, geometría fractal tipo E. STUDY OF AN ANTENNA OF FRACTAL MICROCINTA TYPE E FOR THE BAND OF THE 2.4 GHZAbstractIn this paper, the simulation and experimental study of an E-shape fractal patch antenna for the unlicensed band of 2.4 GHz is presented. The electromagnetic structure of this antenna is analyzed using the High Frequency Structure Simulator HFSS of ANSY, while the experimental antenna prototype is characterized using a network analyzer of 6.5 GHz and a (near-field based) antenna pattern measurement equipment. Simulation results show that the designed antenna presents a resonant frequency of 2.463 GHz with return losses equal to -50 dB, and a coupling bandwidth of 74 MHz. On the other hand, the corresponding experimental parameters are 2.56 GHz, -17 dB, and 100 MHz, respectively. The study performed in this paper demonstrates the suitability of using the E-shape fractal patch antenna for wireless applications at the 2.4 GHz unlicensed band.Keywords: broadband antennas, coupling bandwidth, ISM frequency bands, patch antennas, type-E fractal geometry

Borderline Personality Disorder With Cocaine Dependence: Impulsivity, Emotional Dysregulation and Amygdala Functional Connectivity

Background: Borderline personality disorder is present in 19% of cocaine dependence cases; however, this dual pathology is poorly understood. We wished to characterize the dual pathology and find its functional connectivity correlates to better understand it.Methods: We recruited 69 participants divided into 4 groups: dual pathology (n = 20), cocaine dependence without borderline personality disorder (n = 19), borderline personality without cocaine dependence (n = 10) and healthy controls (n = 20). We used self-reported instruments to measure impulsivity and emotional dysregulation. We acquired resting state fMRI and performed seed-based analyses of the functional connectivity of bilateral amygdala.Results: Borderline personality disorder and cocaine dependence as factors had opposing effects in impulsivity and emotional dysregulation, as well as on functional connectivity between left amygdala and medial prefrontal cortex. On the other hand, in the functional connectivity between right amygdala and left insula, the effect of having both disorders was instead additive, reducing functional connectivity strength. The significant functional connectivity clusters were correlated with impulsivity and emotional dysregulation.Conclusions: In this study, we found that clinical scores of dual pathology patients were closer to those of borderline personality disorder without cocaine dependence than to those of cocaine dependence without borderline personality disorder, while amygdala-medial prefrontal cortex functional connectivity patterns in dual pathology patients were closer to healthy controls than expected