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Synthesis and characterization of nanoparticulate silica with organized multimodal porous structure impregnated with 12-phosphotungstic acid for its use in heterogeneous catalysis

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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

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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

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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

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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

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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.

Efecto de distintos sistemas de producción y formas de sujeción sobre las pérdidas poscosecha en acelga (Beta Vulgaris I. Var. Cicla I.)

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Efecto de distintos sistemas de producción y formas de sujeción sobre las pérdidas poscosecha en acelga (Beta Vulgaris I. Var. Cicla I.); Effect of different production systems and fastening methods on postharvest losses in swiss chard (Beta Vulgaris l. Var. Cicla l.) Grasso, Rodolfo Oscar; Rotondo, Rosana; Ortiz Mackinson, Mauricio Pablo; Mondino, María Cristina; Calani, Paula Andrea; Balaban, David Mario; Vita Larrieu, Eduardo Alberto; Torres, Patricia Susana El trabajo se realizó en la FCA-UNR en otoño, invierno y primavera, con el objetivo de evaluar el efecto de los sistemas de producción, forma de sujeción y días de almacenamiento sobre el rendimiento y las pérdidas poscosecha. El ensayo se realizó teniendo en cuenta tres factores: 1) sistemas de producción: invernadero (I), media sombra (MS), manta flotante (MF) y campo (C), 2) formas de sujeción: manojo (A) y granel (G) y 3) días de almacenamiento. Las variables medidas fueron: rendimiento, materia seca, pérdida de peso por descarte y por agua e índice de color. En las tres épocas, I obtuvo el mayor rendimiento y menor contenido de materia seca. I y MF obtuvieron las menores pérdidas de peso por descarte en otoño; en invierno y otoño aumentan con los días de almacenamiento. I y MF registraron las menores pérdidas de peso por agua en otoño en los días 3 y 6 de almacenamiento. La acelga mostró una tendencia hacia el verde amarillento en MF en otoño, C en invierno e I en primavera, en todos los días de almacenamiento.; This work, carried out in the College of Agricultural Sciences, UNR, in autumn, winter and spring with the objective of evaluating the effect the effect evaluates the effect of production systems, fastening methods and days of storage on yield and postharvest losses on Swiss chard along three seasons. The trial was carried out taking into account three factors: 1) Production systems: greenhouse (I), shade cloth (MS), frost protection fleece fabric (MF), and open field (C); 2) fastening method: bunches (A) and no fastening (G); 3) storage days. The variables measured were: yield, dry matter, weight loss by discarding, weight loss by water, and color index. In all three seasons, I obtained the highest yield and lowest dry matter content. I and MF obtained the least weight loss by discarding in autumn; in winter and autumn they increase with the days of storage. I and MF recorded the lowest weight losses per water in autumn on days 3 and 6 of storage. Chard showed a tendency towards yellowish green in MF in autumn, C in winter and I in spring, in all days of storage.

Longitudinal cognitive and biomarker changes in dominantly inherited Alzheimer disease

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Longitudinal cognitive and biomarker changes in dominantly inherited Alzheimer disease McDade, Eric; Wang, Guoqiao; Gordon, Brian A.; Hassenstab, Jason; Benzinger, Tammie L. S.; Buckles, Virginia; Fagan, Anne M.; Holtzman, David M.; Cairns, Nigel J.; Goate, Alison M.; Marcus, Daniel S.; Morris, John C.; Paumier, Katrina; Xiong, Chengjie; Allegri, Ricardo Francisco; Berman, Sarah B.; Klunk, William; Noble, James; Ringman, John; Ghetti, Bernardino; Farlow, Martin; Sperling, Reisa A.; Chhatwal, Jasmeer; Salloway, Stephen; Graff Radford, Neill R.; Schofield, Peter R.; Masters, Colin; Rossor, Martin N.; Fox, Nick C.; Levin, Johannes; Jucker, Mathias; Bateman, Randall J. Objective To assess the onset, sequence, and rate of progression of comprehensive biomarker and clinical measures across the spectrum of Alzheimer disease (AD) using the Dominantly Inherited Alzheimer Network (DIAN) study and compare these to cross-sectional estimates. Methods We conducted longitudinal clinical, cognitive, CSF, and neuroimaging assessments (mean of 2.7 [±1.1] visits) in 217 DIAN participants. Linear mixed effects models were used to assess changes in each measure relative to individuals' estimated years to symptom onset and to compare mutation carriers and noncarriers. Results Longitudinal β-amyloid measures changed first (starting 25 years before estimated symptom onset), followed by declines in measures of cortical metabolism (approximately 7-10 years later), then cognition and hippocampal atrophy (approximately 20 years later). There were significant differences in the estimates of CSF p-tau181 and tau, with elevations from crosssectional estimates preceding longitudinal estimates by over 10 years; further, longitudinal estimates identified a significant decline in CSF p-tau181 near symptom onset as opposed to continued elevations. Conclusion These longitudinal estimates clarify the sequence and temporal dynamics of presymptomatic pathologic changes in autosomal dominant AD, information critical to a better understanding of the disease. The pattern of biomarker changes identified here also suggests that once β-amyloidosis begins, additional pathologies may begin to develop less than 10 years later, but more than 15 years before symptom onset, an important consideration for interventions meant to alter the disease course.

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