Parabolic megadunes in a subtropical Quaternary inland dune field, southwestern Pampas, Argentina Tripaldi, Alfonsina; Mehl, Adriana Ester; Zárate, Marcelo Arístides The Utracán paleo-dune field (La Pampa Province, Argentina, southern South America) was examined by remote sensing, morphometric analyses and field surveys as a case study of complex megadunes of inland deserts. The paleo-dune field is within the Utracán-Argentino valley, one of the transverse valleys of La Pampa Province excavated into a regional structural plain. Similar paleo-dune fields occur within these valleys. Utracán dunes are mostly stabilized by grasses, deeply disturbed by cattle grazing and agriculture. The paleo-dune field is formed by complex parabolic megadunes with superimposed dunes. Parabolic megadunes present lengths of trailing arms of 3.3–12.9 km, widths between them of 2–2.9 km and heights of 7–38 m. The position of the dune noses at the northeastern tip of the bedform and measured SW-NE orientation of arms indicate a mean transport direction to azimuth 68.2°. Above the parabolic arms, and isolated in the paleo-dune field, there are compound blowout dunes (clusters of several blowouts forming a larger bedform). They show the depositional lobes to the NE, with a measured mean transport direction to azimuth 58.1°. The SW-NE longitudinal length varies between 324 and 1302 m and the NW-SE transverse length between 114 and 622 m. Other parabolic arms show low (<3 m) barchanoid dunes, with crest lengths of 48–811 m, a mean crest spacing of 74 m and a transport direction to azimuth 28.2°. The paleo-dune field also shows smaller, simple parabolic and blowout dunes. We hypothesize that the parabolic and blowout dunes are the basic bedforms that emerged under the boundary conditions of the Utracán dune field, related to a high sediment supply coupled with a partial vegetation cover, in a valley that provided accommodation space by means of well-defined depression and wind deceleration due to a change in the longitudinal valley slope direction. The west-to-east spatial progression of dune morphologies along the Utracán-Argentino valley, the general transport direction of dunes to the NE, and the petrographic sand composition allow us the infer that the transverse valleys of La Pampa Province worked as sand transport pathways. These pathways transferred fine to very fine sand from the eastern Andean piedmont to the Pampean plain, likely during the Quaternary.

Neuroprotective effects of Flaveria bidentis and Lippia salsa extracts on SH-SY5Y cells Cavallaro, Valeria; Baier, Carlos Javier; Murray, María Gabriela; Estevez Braun, Ana; Murray, Ana Paula Halophyte plants have to survive in a hostile environment by developing adaptive responses. One of these strategies is the production of several protective molecules which make these plants an interesting source of bioactive compounds. Significant acetylcholinesterase inhibition was observed for ethanolic extracts obtained from Lippia salsa Griseb. (Verbenaceae) and Flaveria bidentis (L.) Kuntze (Asteraceae), two plants that are widely distributed in the salt marsh Salitral de la Vidriera. These results encouraged us to further study the active constituents and the potential neuroprotective properties of these plants. The flavonoids luteolin (1) and apigenin (2) were identified as the active components of L. salsa, while 6-methoxykaempferol-3-sulfate (3) was obtained from F. bidentis. In addition, we investigated the cytotoxicity, cellular protection against K+-depolarization and antioxidant activity in SH-SY5Y neuroblastoma cells for these extracts and compound 3. Results demonstrated that beyond acting as acetylcholinesterase inhibitors, they also exhibited neuroprotective effects against KCl-induced-Ca2 + overload and oxidative stress.

Iodine-Catalyzed Iso-Nazarov Cyclization of Conjugated Dienals for the Synthesis of 2-Cyclopentenones Marsili, Lucía A.; Pergomet, Jorgelina Leonor; Gandon, Vincent; Riveira, Martín Jorge Molecular iodine was identified as an efficient catalyst for the cycloisomerization of conjugated dienals to substituted 2-cyclopentenones. DFT calculations suggested an unexpected concerted character for this cyclization.

Online third-order liquid chromatographic data with native and photoinduced fluorescence detection for the quantitation of organic pollutants in environmental water Pellegrino Vidal, Rocio; Olivieri, Alejandro Cesar; Ibañez, Gabriela Alejandra; Escandar, Graciela Monica Third-order liquid chromatographic data were generated online for the simultaneous quantitation of six organic environmental pollutants. The employed strategy consists in reducing the linear flow rate at the column outlet. A postcolumn UV reactor and a fluorimetric detector allowed to properly record both photoinduced and native excitation-emission fluorescence matrices (EEPIFMs and EEFMs, respectively). The obtained third-order liquid chromatography data were chemometrically processed with the multivariate curve resolution-alternating least-squares model. The sensitivity of the overall analytical method was enhanced by a very simple solid-phase extraction with C18 membranes, to be able to successfully apply it to natural water samples tested as real matrices. Favorable detection limits for the investigated pollutants, ranging from 0.02 to 0.27 ng mL-1, were attained, with relative prediction errors between 2 and 7%. Since the studied samples contain uncalibrated interferents, the applied strategy achieves the second-order advantage. Implications regarding the potential achievement of the third-order advantage are discussed.

Educación en tiempos de la Confederación Argentina; Education in times of the Argentine Confederation Bustamante Vismara, José Manuel Laureano Este análisis indaga en dos facetas de la política educativa desarrollada bajo el gobierno de la Confederación Argentina en la década de 1850. Por un lado se recuperan rasgos del proyecto alberdiano, sus modulaciones al formularse el artículo quinto de la constitución de 1853, así como las notas introducidas por la reforma de 1860. Luego se estudian aspectos fiscales y educativos de ese gobierno. Con este propósito se atiende a legajos de órdenes de pago del Departamento de Justicia, Culto e Instrucción Pública durante el período comprendido entre 1856 y 1860.; This paper searches two facets of the educational policy developed under the government of the Argentine Confederation in the 1850s. On one hand, traces of the Alberdian project are recovered, their modulations in the formulation of the fifth article of the constitution of 1853, as well as the notes introduced by the reform of 1860. Later we study fiscal and educational aspects of that government; the payment orders of the Department of Justicia, Culto e Instrucción Pública during the period between 1856 and 1860 are analyzed for that purpose.

Ni-based catalysts obtained from perovskites oxides for ethanol steam reforming Aguero, Fabiola Nerina; Alonso, José Antonio; Fernández Díaz, Maria Teresa; Cadus, Luis Eduardo Perovskites as host structures of cations were used in order to generate in situ active and stable catalysts for ethanol steam reforming. For this purpose, La1-xMgxAl1-yNiyO3 (x = 0.1; y= 0, 0.1, 0.2, 0.3) perovskites were synthetized by the citrate method. Ni segregation is evident for a substitution level higher than 0.2. The segregation of Ni as NiO generated species interacts with different metal-support after the reduction step. The y= 0.1 catalyst presents the highest H2 yield value about 85% during reaction time, with low mean values of CH4 and CO selectivities of 3.4% and 11%, respectively and a low carbon formation. The better performance of y= 0.1 catalyst could be attributed to the minor proportion of segregated phases, thus a controlled expulsion of Ni is successfully reached.

Approaches for phosphorus removal with calcium hydroxide and floating macrophytes in a mesocosm experiment: impacts on plankton structure Frau, Diego; Spies, Mariana; Battauz, Yamila Soledad; Medrano, Jonathan; Sinistro, Rodrigo Cultural eutrophication has promoted theapplication of several mitigation strategies in the last50 years. In this study we tested the combined effectsof two techniques: calcium hydroxide [(Ca(OH)2),lime] and a free-floating macrophyte (Salvinia rotundifoliaWilld) to examine the soluble reactive phosphorusremoval capability and the effects on plankton(phytoplankton and zooplankton) structure in a in situlake mesocosms experiment. The experiment lasted10 days (n = 12, 500 l each) with a control and threetreatments (lime (CH), plants (FM), and thecombination of both (CH ? FM)). Samples of severalphysical and chemical variables (including nutrients)and phytoplankton were taken at the beginning, 2 daysafter, 4 days, and 10 days (end of the experiment).Zooplankton was sampled at the beginning and at theend. The highest depletion effect of soluble reactivephosphorus (SRP) was observed in presence of lime.Phytoplankton biovolume was highly and negativelyaffected in lime treatments (CH and CH ? FM).Zooplankton changed from Rotifera to Cladocera andCopepoda in presence of macrophytes. We concludethat lime ? plants reduces more effectively SRP,phytoplankton biovolume and promotes herbivorouszooplankton development; becoming by this way, in asuitable mitigation strategy to be explored in futurefield manipulation studies.

Socio-environmental patterns associated with cancer mortality: A study based on a quality of life approach Pou, Sonia Alejandra; Diaz, Maria del Pilar; Velázquez, Guillermo Ángel Background: With 18.6% of total deaths due to malignant tumors in 2016, cancer is the second leading death cause in Argentina. While there is a broad consensus on common risk factors at the individual cancer level, those operating at a contextual level have been poorly studied in developing countries. The objective of our study was to identify socio-environmental patterns in Argentina (2010), emphasizing quality of life, and to explore their associations with the spatial distribution of cancer mortality in the country. Methods: The study was conducted in 525 geographical divisions nested into 24 provinces. Sex-specific crude and age-standardized mortality rates (ASMR) for cancer (2009-2011 period) were calculated. Empirically derived socio-environmental patterns were identified through principal-component factor analysis on a selected set of variables: an urban scale and 29 indicators of a quality of life index in Argentina for 2010. Two-level Poisson regression models were used to estimate associations between the ASMR and the continuous factor scores for socio-environmental patterns as covariates. A random intercept was included to account for spatial variability in the ASMR distribution using Stata software. Results: Four socio-environmental patterns were identified, termed "Contexts with urban-related resources or cultural capital", "Socioeconomically prosperous contexts", "Environments with anthropic exposures" and "Plains region" (cumulative explained variance=57%). High mortality rates were found in counties characterized by socioeconomically prosperous contexts (RR=1.025 in women; 1.088 in men) and plain landscapes (RR=1.057 and 1.117, respectively). Counties featuring urban or cultural resources demonstrated increased mortality in women (RR=1.015, 95%CI=1.005-1.025), whereas rising rates associated with environments having anthropic exposures (RR=1.008, 95%CI=1.001-1.016) were observed only for men. Conclusion: This study identified four characteristic socio-environmental patterns in Argentina which incorporate features of quality of life, accounting to some extent for the differential burden of cancer mortality in this country.

Metabolic stress and shell thinning in Pomacea canaliculata (Caenogastropoda, Ampullaridae) in rice agroecosystems of Argentina Attademo, Andres Maximiliano; Tamburi, Nicolas Eduardo; Peltzer, Paola; Lajmanovich, Rafael Carlos; Martinuzzi, Candela Soledad Pomacea canaliculata is a freshwater snail native to South America that has become a serious pest of rice crops. Insecticides are used to control other pests in paddy fields and P. canaliculata is collaterally exposed. Here a P. canaliculata population from a rice field (RF) where the insecticides bifenthrin and imidacloprid (IMC) were applied was compared with a reference site (RS). The activities of three metabolic endpoints, namely acetylcholinesterase (AChE), carboxylesterase (CbE) and glutathione-S-transferase (GST) were measured to test metabolic stress. Intestine and midgut-gland of snails after 7 and 30 days of insecticide application were studied. A possible effect of IMC on shell thickness was also explored. The results indicate an inhibition of CbE and GST activities in the intestine of RF snails relative to RS snails at 7 days, while AChE and GST increased in the intestine after 30 days of IMC exposure. GST in the midgut-gland of RF snails was inhibited with respect to RS snails at 7 and 30 days, whereas CbE increased at 30 days in RF snails. Thinner shells with lower proportion of ash content were observed in snails from RF. Exposure to pesticides exerts neurotoxic resistance and oxidative stress in P. canaliculata and is probably responsible for the alteration in the shell development.

Formalin-ethyl acetate concentration, FLOTAC Pellet and anal swab techniques for the diagnosis of intestinal parasites Cociancic, Paola; Rinaldi, Laura; Zonta, Maria Lorena; Navone, Graciela Teresa The aim of this study was to compare formalin-ethyl acetate concentration and FLOTAC Pellet techniques for the diagnosis of intestinal parasites in human stool samples. The anal swab method was used for the specific detection of Enterobius vermicularis. The study was performed in children and youth from Puerto Madryn (South Argentina). A total of 174 individuals were examined using the formalin-ethyl acetate concentration technique (FECT), the FLOTAC Pellet technique with saturated sodium chloride and zinc sulphate flotation solutions and anal swabs. The performance of copromicroscopic techniques was evaluated according to sensitivity, negative predictive value and Kappa index. Overall, 39.1% of the individuals were parasitised. The most prevalent species was Blastocystis sp. (19%) followed by E. vermicularis (17.8%), Giardia lamblia (6.3%), Entamoeba coli (5.7%), Hymenolepis nana and Endolimax nana (1.1%). The FECT was the most sensitive technique for Blastocystis sp., G. lamblia and E. coli infections, whereas FLOTAC Pellet techniques were the most sensitive for H. nana diagnosis. Anal swabs detected the highest percentage of E. vermicularis infection. This was the first time that the FLOTAC Pellet technique was used to detect intestinal parasites in humans. The FECT continues to be a reliable method for detecting protozoa and the FLOTAC Pellet technique gains importance in the diagnosis of helminths. Anal swab test remains the method of choice for the detection of E. vermicularis. However, when comparing techniques, key factors as preservation methods, preservation times and flotation solutions should be taken into account.

Antifungal and antimycotoxigenic metabolites from native plants of northwest Argentina: isolation, identification and potential for control of Aspergillus species Gómez, Analia de Los Angeles; Terán Baptista, Zareath Pamela; Mandova ,Tzvetelina; Barouti,Angeliki; Kritsanida, Marina; Grougnet Raphael; Vattuone, Marta Amelia; Sampietro, Diego Alejandro Extracts from aerial parts of Prosopis ruscifolia, Bidens pilosa, Cercidium praecox and Phoradendron liga were assayed against toxigenic Aspergillus species. They were obtained by sequential extraction of the aerial parts with hexane (fHex), dichloromethane (fDCM), ethyl acetate (fEtOAc) and methanol (fMeOH). The fMeOH from P. ruscifolia showed the highest antifungal spectrum (MIC = 750–1500 µg mL−1; MID = 50–200 µg; DI = 1.7–3.0 mm). Indolizidine alkaloids (juliflorine and juliprosine) and tryptamine were identified with strong (MIC = 188 µg mL−1) and moderate antifungal activities (MIC = 750 µg mL−1), respectively, towards A. parasiticus and A. flavus. The fMeOH, the indolizidine alkaloids and tryptamine synergized the fungitoxic effect of potassium sorbate and propiconazole. They completely suppressed the biosynthesis of aflatoxins at concentrations of 47, 94 and 375 µg mL−1, respectively. Our results indicate that fMeOH and its identified alkaloids are promisory additives of commercial antifungals and are antiaflatoxigenic agents at concentrations below of those required for complete suppression of fungal growth.

Intraplate seismicity recorded by a local network in the Neuquén Basin, Argentina Correa Otto, Sebastian Ariel; Nacif Suvire, Silvina Valeria; Pesce, Agustina; Nacif, Andres Antonio; Gianni, Guido Martin; Furlani, Renzo; Gimenez, Mario Ernesto; Ruiz, Juan Francisco Intraplate seismicity in the Southern Central Andes has been mostly documented to the north of 35°S, while similar phenomenon south of these latitudes is not known so far. In order to contribute to this issue, we analysed seismicity in the Andean back-arc region between 38°S and 39°S through a seismological experiment using a local broadband seismic network in the Neuquén Basin. In this study, we aim to determine the background (base) seismicity of the region, and integrate the results with gravimetric data and previous geological knowledge to identify potential sources of the seismic activity. In addition to low-grade seismicity we recorded a Ml = 3.78 strike-slip earthquake ∼ 100 km west of Neuquén city on November 19, 2015. Seismicity location could be controlled by thermo-mechanical properties of the lithosphere linked to the previous tectonic evolution. On the other hand, the triggering factor could be related to E-W Andean stress-field or to human-induced activity.

Different nest predator guild associated with egg size in the Patagonian temperate forest Vazquez, Miriam Soledad; Rodriguez Cabal, Mariano Alberto; Gonzalez, Daniela Vanesa; Pacheco, Gabriel S.; Amico, Guillermo Cesar Capsule: Studies of nest predation using artificial nests need to consider the effect of egg size on the types of predator that are detected. Aims: To estimate the nest predation rate in the Patagonian temperate forest and evaluate the influence of egg size on predator guild. Methods: On different plant species, we placed 108 nests each containing eggs of either Atlantic Canary Serinus canaria or Common Quail Coturnix coturnix, and a model clay egg of equal size to the real egg. Nest predators were identified from the marks left on the clay eggs or by videos recorded using camera traps. Results: 86% of the nests were predated. Birds, mainly Chimango Caracara Milvago chimango, were the main nest predators. A marsupial, the Monito del Monte Dromiciops gliroides, and rodents also contributed to nest predation. Nest predation rates were similar for both egg sizes but the nest predator guild was different. Birds and rodents preyed on both eggs but the Monito del Monte consumed mainly small eggs. Conclusion: Egg size did not influence the rate of nest predation but, instead, affected the nest predator guild. Consequently, in order to avoid underestimating the impacts of small predators, egg size should be considered in studies of nest predation.

Análisis de eficiencia en sistemas de cómputo de alta performance reconfigurables Morales, Martín; Kunysz, Eduardo Jose; Osio, Jorge Rafael; Rapallini, Jose Antonio El objetivo de este trabajo, es presentar la arquitectura y características de un sistema para el estudio de las nuevas técnicas de procesamiento paralelo en el desarrollo de sistemas de cómputo de aplicaciones específicas de altas prestaciones. Como opción en la optimización de rendimiento y reducción en los consumos energéticos se propone una alternativa que representa un nuevo paradigma en el desarrollo de supercomputadoras. Dicha alternativa, viene de la mano de tecnologías de arreglos de compuertas lógicas formando parte del cómputo de alta performance reconfigurable (HPCR).; The purpouse of this project is to introduce the architectures and characteristics for new technics of high performance computing paralleling process. As an option of optimization, performance and high energy efficient is propose a new paradigm in supercomputers design. This alternative has came with logic array technology as a part of high performance reconfigurable computer (HPRC).

Ciencia y comunicación: Una experiencia de producción audiovisual en el marco de políticas públicas inclusivas en Argentina; Ciência e comunicação: Uma experiência de produção audiovisual no âmbito das políticas públicas inclusivas na Argentina; Science and Communication: An Experience with an Audiovisual Production within the Framework of Inclusive Public Policies in Argentina Chaparro, Maria Gabriela; Conforti, María Eugenia; Giacomasso, Maria Vanesa En este trabajo se analiza la creación de un material audiovisual de divulgación científica posibilitado por una serie de políticas públicas llevadas a cabo en la última década en Argentina. El objetivo central del artículo es mostrar la relación ineludible entre la agenda del Estado en materia de comunicación, ciencia y tecnología, y la efectivización de proyectos de comunicación de contenidos científicos. La experiencia que aquí se presenta consiste en la producción de una miniserie televisiva realizada con recursos de una universidad pública del interior del país, que aborda temas de arqueología e historia de la región pampeana e incluye diversas voces vinculadas con la identidad local.; Este trabalho analisa a criação de um material audiovisual de divulgação científica, possibilitado por uma série de políticas públicas desenvolvidas na última década na Argentina. O objetivo central do artigo é mostrar a relação incontornável entre a agenda do Estado em termos de comunicação, ciência e tecnologia, e a efetivação de projetos de comunicação de conteúdos científicos. A experiência aqui apresentada está relacionada à produção de uma minissérie de televisão realizada com recursos de uma universidade pública do interior do país, que aborda temas de arqueologia e história da região dos pampas e inclui várias vozes relacionadas à identidade local.; This paper analyses the creation of a science popularization audiovisual work made possible by a series of public policies carried out in the last decade in Argentina. Its central objective is to show the unavoidable relationship between the State’s agenda with regard to communication, science and technology, and the implementation of projects for communicating scientific content. The experience that is here presented is the production of a television miniseries made with resources from a public university from the interior of the country. This miniseries addresses subjects related to archaeology and history from the Pampas region and includes diverse voices connected to its local identity.

Synthesis and characterization of nanoparticulate silica with organized multimodal porous structure impregnated with 12-phosphotungstic acid for its use in heterogeneous catalysis Morales, María Dolores; Frenzel, Romina Alejandra; Romanelli, Gustavo Pablo; Pizzio, Luis Rene Mesoporous silica (MESSI) nanoparticles with ordered mesoporous frameworks were successfully obtained using the triblock copolymer P123 as the mesoporous template and agar as micropore former. The agar/TEOS ratio influences the specific surface area (SBET) and the micropore area (SMIC). The SBET values increase with the increment of the agar/TEOS ratio used in the synthesis. SAXS (small angle X-ray scattering) patterns and TEM (transmission electron microscopy) images of MESSI samples reveal the presence of a 2D hexagonal mesopore array. The study of all the materials impregnated with PTA by 31P NMR and FT-IR confirmed the existence of undegraded [H3-XPW12O40](3−X)− and [PW12O40]3− anions interacting with the ≡Si-OH2 + groups. The potentiometric titration results show that the MESSI-2PTA solids present very strong acid sites and that both the acid strength and the number of sites increase with the increment of the PTA amount in the samples. The performance of MESSI-2PTA materials as catalysts in the solvent-free synthesis of a series of substituted 3H-1,5-benzodiazepines was evaluated. The yields achieved were high, without formation of by-products resulting from competitive reactions or decomposition products, so the prepared materials are highly selective and reusable catalysts.

Alpha 1 adrenergic receptor-mediated inflammatory responses in human testicular peritubular cells Rossi, Soledad Paola; Walenta, Lena; Rey Ares, Veronica; Köhn, Frank-Michael; Ulrich Schwarzer, J.; Welter, Harald; Calandra, Ricardo Saul; Frungieri, Monica Beatriz; Mayerhofer, Artur Stress activates the sympathetic nervous system and is linked to impaired fertility in man. We hypothesized that catecholamines by acting on testicular cells have a role in these events, possibly by fostering an inflammatory environment. The cells of the wall of seminiferous tubules, human testicular peritubular cells (HTPCs), express adrenergic receptors (ADRs) α1B, α1D, β1 and β2. A selective α1-ADR agonist, phenylephrine, increased intracellular Ca 2+ -levels in cultured HTPCs and induced COX-2, IL-6 and MCP-1 mRNA expression without affecting IL-1β mRNA. These changes were paralleled by a significant increase in the secretion of IL-6 and MCP-1. Epinephrine was also effective, but salbutamol, a selective β2-ADR agonist was not. Our results suggest that stress-associated elevation of catecholamines may be able to promote inflammatory events by targeting peritubular cells in the human testis. Blockage of α1-ADRs may therefore be a novel way to interfere with stress-related impairment of male reproductive functions.

Polymer functionalized nanoparticles in liquid crystals: Combining PDLCs with LC nanocomposites Allie, Safiya; Hegoburu, Ignacio; Shin, Min Jeong; Jung, Jung Young; Toader, Violeta; Rey, Alejandro D.; Soulé, Ezequiel Rodolfo; Reven, Linda Liquid crystal (LC)-polymer blends are important stimuli responsive materials already employed in a wide range of applications whereas nanoparticle (NP)-LC blends are an emerging class of nanocomposites. Polymer ligands offer the advantages of synthetic simplicity along with chemical and molecular weight tunability. Here we compare the phase behavior of 5CB blended with poly(ethylene oxide) (PEO) and with gold NPs functionalized with thiolated PEO (AuNP-PEO) as a function of PEO concentration by DSC, POM and 13C NMR spectroscopy. Both PEO and the AuNP-PEO form uniform dispersions in isotropic 5CB and phase separate below the I-N phase transition temperature. Above the PEO crystallization temperature, the PEO/5CB blends show the expected biphasic state of PEO rich-isotropic liquid co-existing with PEO-poor nematic droplets. At PEO concentrations above 10 wt%, nematic 5CB nucleates with PEO crystallization. Both PEO and AuNP-PEO induce homeotropic alignment of the 5CB matrix immediately below TNI. The AuNP-PEO/5CB blends form thermally reversible cellular networks similar to AuNPs functionalized with low molecular weight mesogenic ligands. A thermodynamic model to account for the observed phase behavior is presented.

Self-assembly of a drop pattern from a two-dimensional grid of nanometric metallic filaments Cuellar Berrio, Ingrith Paola; Ravazzoli, Pablo Damián; Diez, Javier Alberto; Gonzalez, Alejandro Guillermo; Roberts, Nicholas A.; Fowlkes, Jason D.; Rack, Philip D.; Kondic, Lou We report experiments, modeling, and numerical simulations of the self-assembly of particle patterns obtained from a nanometric metallic square grid. Initially, nickel filaments of rectangular cross section are patterned on a SiO2 flat surface, and then they are melted by laser irradiation with ∼18-ns pulses. During this time, the liquefied metal dewets the substrate, leading to a linear array of drops along each side of the squares. The experimental data provide a series of SEM images of the resultant morphology as a function of the number of laser pulses or cumulative liquid lifetime. These data are analyzed in terms of fluid mechanical models that account for mass conservation and consider flow evolution with the aim to predict the final number of drops resulting from each side of the square. The aspect ratio, δ, between the square sides' lengths and their widths is an essential parameter of the problem. Our models allow us to predict the δ intervals within which a certain final number of drops are expected. The comparison with experimental data shows a good agreement with the model that explicitly considers the Stokes flow developed in the filaments neck region that lead to breakup points. Also, numerical simulations that solve the Navier-Stokes equations along with slip boundary condition at the contact lines are implemented to describe the dynamics of the problem.

Efficient production of glycosylated and non-glycosylated mycobacterium tuberculosis antigen 85B fused to PVX coat protein in Nicotiana benthamiana plants González, Pablo A.; Puccio, Franco Damián; Zelada, Alicia Mercedes The development of alternative subunit based-vaccines against tuberculosis is necessary due to variable efficiency and some security concerns of the BCG vaccine. The aim of this work was evaluate the production of the Mycobacterium tuberculosis Ag85B antigen fused to Potato Virus X Coat Protein (PVX-CP) by transient expression in Nicotiana benthamiana for subunit-based tuberculosis vaccine formulation. A codon-optimized M. tuberculosis Ag85B gene was fused to PVX-CP and expressed both as a full length precursor and as a mature version lacking the leader peptide. Signal peptides of N. tabacum genes were added to precursor and mature Ag85B-CP to compare the efficiency of cytoplasmic and apoplastic expression. Constructs were agroinfiltrated into N. benthamiana leaves and the yield and integrity of recombinant proteins were analysed. Glycosylation status was determined by treatment with peptide N-glycosidase F. The highest amounts of fusion protein were obtained by expressing mature Ag85B lacking its leader sequence directed to the apoplast, which reached a yield of 100 mg of antigen per kg of fresh leaf. Glycosylated and non-glycosylated fusion proteins were obtained in the apoplastic and cytoplasmic space, respectively. We showed the feasibility of producing Ag85B-CP protein in N. benthamiana leaves for application as a subunit vaccine and demonstrated the importance of expressing mature Ag85B to increase yield and to avoid the production of degraded protein fragments unsuitable for a pharmaceutical product.