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

New objects in old structures: The Iron Age hoard of the Palacio III megalithic funerary complex (Almadén de la Plata, Seville, Spain)

Cultural contact, exchange and interaction feature high in the list of challenging topics of current research on European Prehistory. Not far off is the issue of the changing role of monuments in the making and maintaining of key cultural devices such as memory and identity. Addressing both these highly-debated issues from a science-based perspective, in this paper we look at an unusual case study set in southern Iberia and illustrate how these archaeological questions can benefit from robust materials-science approaches.We present the contextual, morphological and analytical study of an exceptional Early Iron Age hoard composed of a number of different (and mostly exotic) materials such as amber, quartz, silver and ceramic. This hoard, found under the fallen orthostat of a megalithic structure built at least 2000 years earlier, throws new light on long-distance exchange networks and the effect they could have had on the cultural identities and social relations of local Iberian Early Iron Age communities. Moreover, the archaeometric study reveals how diverse and distant the sources of these item are (Northern Europe to Eastern and Western Mediterranean raw materials, as well as local and eastern technologies), therefore raising questions concerning the social mechanisms used to establish change and resistance in contexts of colonial encounter

Crónica del Plantel Sor Juna Inés de la Cruz frente a la pandemia del Covid-19

El semestre se desarrollaba, “aparentemente normal”, estábamos en el mes de marzo de 2019, ya había noticias de que, en China, específicamente en la ciudad de Wuhan, provincia de Hubei (31 de diciembre de 2019), habían informado de 27 casos de un tipo de neumonía de etiología desconocida, y siete de estos casos eran severos, la infección llegó a China. El número de infectados creció a miles (9,692), miles de ellos enfermaron de gravedad. Para el mes de enero de 2020, se hablaba de un virus llamado Covid-19 y ese mismo mes se reportó la primera muerte por este virus

The state of international collaboration for health systems research: what do publications tell?

AIM: International collaboration for health system development has been identified as a critical input to meet pressing global health needs. North-South collaboration has the potential to benefit both parties, while South-South collaboration offers promise to strengthen capacity rapidly and efficiently across developing countries. There is an emerging trend to analyze the fruits of such collaboration. This paper builds on this trend by applying an innovative concept-based bibliometric method to identify the international scope of collaboration within the field of health policy and systems research. Two key questions are addressed: to what extent are papers comparing developing countries as against reporting on single country studies? To what extent are papers in either case being produced by researchers within their respective countries or through North-South or South-South collaboration? METHODS: A total of 8,751 papers published in Medline between 1999 and 2003 with data on health systems and policies in developing countries were identified and content-analyzed using an innovative concept-based search technology. A sample of 13% of papers was used to identify the corresponding institution and countries covered. The sampled data was then analyzed by income group. RESULTS: Papers with an international, cross-country focus account for only 10% of the total. Just over a third of all papers are led by upper middle income country authors, closely followed by authors from high income countries. Just under half of all papers target low income countries. Cross-country papers are led mostly by institutions in high income countries, with 74% of the total. Only seven countries concentrate 60% of the papers led by developing country institutions. Institutions in the United States and the United Kingdom concentrate between them as many as 68% of the papers led by high income countries. Only 11% of all single-country papers and 21% of multi-country studies are the product of South-South collaboration. Health Financing is the topic with the greatest international scope, with 26% of all papers in the topic. Topics such as Costing and Cost Effectiveness, Finance, Sector Analysis and Insurance, regardless of their national or international scope, are led in 38% to 54% of cases by high income authors. CONCLUSION: While there is modest health systems research capacity in many developing countries for single country studies, capacity is severely limited for multi-country studies. While North-South collaboration is important, the number of international studies is still very limited to produce the kind of knowledge required to learn from experiences across countries. The fact that lead institutions as well as study countries are concentrated in a handful of mostly middle income countries attests to great disparities in research capacity. However, disparities in research capacity and interest are also evident in the North. It is urgent to build cross-country research capacity including appropriate forms of South-South and North-South collaboration

Antioksidativna aktivnost ferementiranih i nefermentiranih esktrakata iz otpada nastalog pri proizvodnji kave

Coffee pulp contains natural antioxidants like hydroxycinnamic acids, most of which are covalently linked to the cell wall. These compounds can be released by fermentation or enzymatic processes. In this study, the antioxidant properties of fermented and nonfermented coffee pulp have been evaluated. Coffee pulp was fermented by solid-state fermentation using the fungus Aspergillus tamarii. Fermented and nonfermented samples of coffee pulp were extracted with aqueous methanol followed by alkaline hydrolysis. In both cases, the total polyphenol concentration was quantified by Folin-Ciocalteu method, then hydroxycinnamic acids were concentrated using ethyl acetate and quantified by HPLC. The antioxidant properties of samples were determined by radical monocation of 2,2’-azinobis-( 3-ethylbenzothiazoline-6-sulphonic acid) [ABTS]·+: the antioxidant activity was determined by kinetic parameters known as ED50, tED50 and antiradical efficiency (AE). Fermented extracts containing free hydroxycinnamic acids showed better antiradical activity against [ABTS]·+ than the other nonfermented ones. There were no significant differences in the total content of polyphenols in fermented and nonfermented coffee pulp, but the content of total hydroxycinnamic acids was higher in the nonfermented coffee pulp extracts (47.1 g/kg) than in the fermented coffee pulp (30.9 g/kg). Nevertheless, the fermentation process increased the fraction of free hydroxycinnamic acids (47 %) and consequently decreased those covalently linked to the cell wall. The results of the antioxidant activity assays could be explained by the presence of free hydroxycinnamic acids. Fermented coffee pulp assays showed that free hydroxycinnamic acids were metabolised by A. tamarii. This study shows the potential of using coffee pulp as a natural source of antioxidants.Otpad nastao pri proizvodnji kave sadržava prirodne antioksidanse, kao što su hidroksicinamične kiseline, od kojih je većina kovalentno vezana za staničnu stijenku. Takvi se spojevi mogu osloboditi fermentacijom ili pomoću enzima. U ovom su radu istražena antioksidativna svojstva fermentiranih i nefermentiranih esktrakata, pri čemu je fermentacija provedena s pomoću plijesni Aspergillus tamarii na čvrstoj podlozi od otpada nastalog pri proizvodnji kave. Fermentirani i nefermentirani spojevi esktrahirani su vodenom otopinom metanola, nakon čega je provedena njihova alkalna hidroliza. U oba je slučaja koncentracija ukupnih polifenola određena Folin-Ciocalteu metodom, a zatim su hidroksicinamične kiseline koncentrirane pomoću etil acetata i analizirane HPLC-om. Antioksidativna su svojstva uzoraka, tj. vrijednosti ED50 i tED50 te antiradikalni učinak, određena pomoću radikala 2,2\u27-azinobis(3-etilbenzotiazolin-6-sulfonske kiseline) [ABTS].+. Fermentirani su ekstrakti sadržavali slobodne hidroksicinamične kiseline i imali su bolju antioksidativnu aktivnost s obzirom na [ABTS].+ od nefermentiranih ekstrakata. Nije bilo bitne razlike u koncentracijama ukupnih polifenola u fermentiranim i nefermentiranim ekstraktima, ali je udio hidroksicinamičnih kiselina bio veći u nefermentiranim (47,1 g/kg) nego u fermentiranim ekstraktima (30,9 g/kg). Fermentacija je povećala udjel slobodnih (na 47 %), a smanjila udjel vezanih hidroksicinamičnih kiselina. Zaključeno je da je antioksidativna aktivnost ekstrakata ovisila o udjelu slobodnih hidroksicinamičnih kiselina, koji se povećao nakon fermentacije otpada nastalog pri proizvodnji kave s pomoću A. tamarii. Time je potvrđeno da se postupak može primijeniti za ekstrakciju prirodnih antioksidanasa

Molecular and biochemical characterization of extracellular tannin acyl hydrolase activity from a Mexican isolate of Aspergillus niger

"Microbial tannase, a hydrolysable tannin-degrading enzyme, is extensively used in manufacture of instant tea, beer, wine, and gallic acid. Aspergillus niger strain, obtained from a Mexican tannery wastewaters rich in gallic acid [Quebracho Phenolics-rich Tannery Wastewaters, (QPTW)], displayed a good growth and tannase activity in a minimal medium added with 1% (w/v) QPTW (Kr= 0.451 mm.h-1). Using PCR and RACE 3´ and 5´methodologies, a complete cDNA of a tannase was cloned from this isolate.Nucleotide sequence of complete cDNA was of 4690 bp with a complete ORF of 1833 bp encoding 611 amino acids. Transcriptionalinduction was observed in mineral medium added with carbon sources as tannic acid alone (1 and 10 g/l), as well as mix of glucose(1 and 10 g/l) and tannic acid (1 g/l) in the media. However, neither glucose (1 and 10 g/l) and sucrose (1 and 10 g/l) nor (+)-catechin(1 and 10 g/l) as sole carbon sources displayed gene induction in in vitro assays. A. niger-GTO is a new strain with interesting characteristics for industrial tannase production purposes.

Comparison of 1-repetition-maximum performance across 3 weightlifting overhead pressing exercises and sport groups

Objective: This study aimed to (I) compare the one repetition maximum (1RM) performance between the push press (PP), push jerk (PJ) and split jerk (SJ), and (II) explore these differences between weightlifters, CrossFit® athletes and a mixed group of athletes. Method: Forty-six resistance trained male (age: 28.8 ± 6.4 years; height: 180.0 ± 6.0 cm; body mass: 84.1 ± 10.2 kg; weightlifting training experience: 3.64 ± 3.14 years) participated in this study. The 1RM performance of the PP, PJ and SJ were assessed during the same session in a sequential order (i.e. combined 1RM assessment method). Thirty-six participants were re-tested to determine between-session reliability of the 1RM values. Results: Intraclass correlation coefficients (ICC) and associated 95% confidence intervals showed a high between-session reliability for the PP (ICC = 0.98 [0.95-0.99]), PJ (ICC = 0.99 [0.98-1.00]) and SJ (ICC = 0.99 [0.98-1.00]). There was a significant main effect of exercise (2 = 0.662) and exercise x group interaction (2 = 0.066) on the 1RM performance (p<0.0001), while the main effect of group did not reach statistical significance (p=0.072). Conclusion: This study provides evidence that the weightlifting overhead pressing derivatives impact the 1RM performance. In addition, the interaction of exercise and sport group was caused by the higher differences in the 1RM performance between-exercises for weightlifters compared to CrossFit® and a mixed group of athletes. Therefore, strength and conditioning professionals should be aware that the differences in 1RM performance between weightlifting overhead pressing derivatives may be affected by the sport group