Establishment of cell suspension cultures of prosopis laevigata (humb. & bonpl. ex willd) m.c. johnst to determine the effect of zinc on the uptake and accumulation of lead

In vitro studies indicate that Prosopis laevigata can be considered a potential hyperaccumulator of lead. Likewise, lead uptake has been related to protein transporters for zinc. In this work presents a protocol for the establishment of cell suspension culture to determine the effect of zinc on the uptake and accumulation of lead. A bioassay with Pb2+/Zn2+ (0.0, 0.5, and 1.0 mM) was carried out on cell suspension cultures derived from callus induced in half-strength Murashige and Skoog (MS) medium added with 6.8 pM 2,4-dichlorophenoxyacetic acid (2,4-D) with 4.5 pM kinetin (KIN). Cells showed significant tolerance to growth (GR>60%) at all concentrations and combinations of Pb and Zn (0.0, 0.5 and 1.0 mM). When the Pb with or without Zn were added to the culture medium, the cells showed the highest accumulation efficiency for non-essential (lead) metal over essential (zinc) metal (BF values for Pb » BF values for Zn; 2-33 times). Scanning electron micrographs evidenced the accumulation of Pb in the cells walls. These results provide insights about the tolerance and accumulation mechanisms of Pb occurring in P. laevigata

Acumulación simultánea de múltiples metales pesados por cultivos in vitro de plántulas de Prosopis laevigata

Se investigó la capacidad de plántulas de Prosopis laevigata para tolerar y acumular de forma simultánea hasta 4 metales pesados (cromo, níquel, cadmio y plomo), bajo condiciones de cultivo in vitro.Experiments were conducted to investigate the capability of Prosopis laevigata to individually or simultaneously uptake four heavy metals (HM; Cr, Ni, Cd, and Pb). To this end, P. laevigata seedlings were cultured during 50 days on modified MS medium supplemented with 30 g L−1 of sucrose and added with 1, 2, 3 or 4 HM (50 mg L−1 of each HM). When the four HM were added simultaneously, the medium was supplemented with or without ethylenediaminetetracetic acid (EDTA). In the MS media contained only one HM, the seedlings tolerance to HM was as follows: Pb≥Cr>Ni≥Cd. The accumulation of HM from higher to lower concentration in shoots was Pb≥Ni>Cd>>Cr and in roots Cr>>Pb>>Ni>Cd. When the media contained more than one HM, the accumulation in shoots was the highest for Ni and the lowest for Pb, whether EDTA was added or not. EDTA supplementation increased 61, 39, 22, and 3 fold uptake of Cr, Ni, Pb, and Cd in roots, respectively

Crosslinked Chitosan Films Supplemented with <i>Randia</i> sp. Fruit Extract

This work proposes the development of a polymer film made up of affordable components for its use as a healthcare material. Chitosan, itaconic acid, and Randia capitata fruit extract (Mexican variation) are the unique ingredients of this biomaterial prospect. Chitosan (from crustacean chitin) is crosslinked with itaconic acid, and in situ added R. capitata fruit extract in a one-pot reaction carried out in water as the sole solvent. Structurally, the film formed is an ionically crosslinked composite characterized by IR spectroscopy and thermal analysis (DSC and TGA); cell viability was also performed in vitro using fibroblasts BALB/3T3. Dry and swollen films were analyzed to determine affinity and stability in water. This chitosan-based hydrogel is designed as a wound dressing due to the combined properties of the chitosan with R. capitata fruit extract, which has potential as bioactive material due to its properties in epithelial regeneration

Anammox activity of sludge coming from wetland monocots (typha sp.): kinetic study actividad anammox

The anaerobic ammonium oxidation (anammox) activity was evaluated using sludge obtained from the rhizome of Typha sp., found in a natural wetland localized in the J´ose Antonio ´ Alzate dam, Toluca Valley,Mexico. Five NO2 -N concentrations (15, 30, 50, 70 and 100 mg/L) were evaluated and the ammonium remained constant at 100 10 mg N/L. All cultures presented a lag phase in the ammonium consumption. Nevertheless, after the phase lag the ammonium oxidation was linked to nitrite reduction, producing N2. The nitrite consumption eciencies for the concentrations evaluated from 15 to 50 mg/L of NO2 -N were above 95%, while the ammonium consumption eciency increased from 14 to 48%. In experiments with 70 and 100 mg/L of NO2 -N, nitrite consumption eciencies were 74 and 58% respectively. The higher nitrite concentrations tested inhibited the anammox process since the specific rates diminished at 0.51 and 0.44 mg NO2-N/g VSS d respectively. This study provides new and useful information about the anammox activity in sludges coming from wetlands, and these can be used as potential inoculum to treat wastewaters into anammox reactors, or in constructed wetlands

Micropropagation of Buddleja cordata and the content of verbascoside and total phenols with antioxidant activity of the regenerated plantlets

Buddleja cordata is a medicinal plant distributed in Mexican territory that is characterized for producing phenolic compounds possessing antioxidant activity. It was evaluated the type of morphogenetic responses induced by plant growth regulators. Furthermore, the content of verbascoside and total phenols was determined, as well as the antioxidant activity in regenerated plantlets. The greatest shoot proliferation (29.2 shoots per explant) was achieved in the stem-nodes that were grown in a half-strength Murashige and Skoog medium containing 4.44 µM N6-benzyladenine. The greatest shoot heights of 4.3 and 4.7 cm (statistically not different) were obtained with gibberellic acid at 4.34 and 8.67 µM, respectively. The highest percentage of rooting (89.4%) occurred with 2.45 µM indole-3-butyric acid with 20.3 roots per shoot and an average root length of 4.4 cm. Of the rooted shoots, 91.7% were able to survive after 30 days of acclimatization. The verbascoside (1.0 mg g-1) and total phenols (24.8 mg of gallic acid equivalents g-1) content was related to antioxidant activity of the regenerated plantlets. The micropropagation of B. cordata might represent an alternative about massive production and depict the basis of the establishment of commercial crops and genetic studies

Acid hydrolysis of composites based on corn starch and trimethylene glycol as plasticizer

Corn starch-based films with trimethyilene glycol (1,3-propanediol) as plasticizer were prepared with the castingtechnique and subject to acid hydrolysis (HCl 1.0 M) at 20 oC. The film degradation was monitored by changes in surfacemorphology, crystallinity, thermal properties and surface wettability. In the first two days, the hydrolysis showed lowadvance to subsequently exhibit a huge increase of the reaction rate. It suggested that surface erosion is the main mechanisminvolved in the film degradation. XRD showed the presence of poly-1,3-propanediol, attributed to condensation reactionof plasticizer in acidic conditions. Thermal analysis showed two endothermic peaks at 110-120 oC attributed to meltingof crystallized amylopectin and to a lesser extent co-crystallized amylose and amylopectin. The temperature of thesepeaks was not affected by hydrolysis time, supporting the idea that hydrolysis reactions are constrained to the film surface.Contact angle measurements indicated a significant decrease of hydrophobicity caused by fractionation of starch chains

Demandasol

Se desarrolla un proyecto de innovación educativa que pretende trabajar sobre las energías renovables y el medio ambiente, demandando un uso de las energías renovables, especialmente la energía solar, concienciando sobre el ahorro energético y exigiendo el cuidado del medio natural en general de la Tierra, y concretamente por la Sierra de la Demanda. Aprovechando la instalación en le centro de un conjunto de placas solares cubriendo así sus necesidades energéticas, se propone un proyecto de innovación educativa que genere materiales y recursos novedosos y prácticos sobre las energías renovables. El proyecto tiene diversos objetivos: establecer un sistema de trabajo que permita al alumnado encargarse de la gestión, mantenimiento, recogida y publicación de los datos obtenidos de las placas solares; elaborar un cuaderno de campo en el que se registren los datos diarios derivaos de la gestión de las placas solares; establecer los tratamiento adecuados a los datos obtenidos: elaborar diversos materiales didácticos; trabajar en el aula con el alumnado las actividades elaboradas; integrar las actividades en la programación anual de cada uno de los departamentos; proporcionar alas diferentes áreas implicadas recursos metodológicos para el tratamiento de sus materias; crear una página Web y publicar los resultados en ella; realizar visitas con los alumnos y alumnas a diferentes centrales de producción de energía; fomentar el trabajo en equipo; sensibilizar a los miembros de la comunidad educativa sobre la necesidad del ahorro energético, el reciclaje y el respeto del medio ambiente, avanzando hacia un modelo de centro energéticamente autosuficiente. El proyecto se aborda desde todas las asignaturas impartidas en el centro, distribuyendo el trabajo y ámbito de actuación en cuatro grupos: de ciencias, de letras, de idiomas y un grupo mixto.Castilla y LeónConsejería de Educación. Dirección General de Universidades e Investigación; Monasterio de Nuestra Señora de Prado, Autovía Puente Colgante s. n.; 47071 Valladolid; +34983411881; +34983411939ES

Contemporary use of cefazolin for MSSA infective endocarditis: analysis of a national prospective cohort

Objectives: This study aimed to assess the real use of cefazolin for methicillin-susceptible Staphylococcus aureus (MSSA) infective endocarditis (IE) in the Spanish National Endocarditis Database (GAMES) and to compare it with antistaphylococcal penicillin (ASP). Methods: Prospective cohort study with retrospective analysis of a cohort of MSSA IE treated with cloxacillin and/or cefazolin. Outcomes assessed were relapse; intra-hospital, overall, and endocarditis-related mortality; and adverse events. Risk of renal toxicity with each treatment was evaluated separately. Results: We included 631 IE episodes caused by MSSA treated with cloxacillin and/or cefazolin. Antibiotic treatment was cloxacillin, cefazolin, or both in 537 (85%), 57 (9%), and 37 (6%) episodes, respectively. Patients treated with cefazolin had significantly higher rates of comorbidities (median Charlson Index 7, P <0.01) and previous renal failure (57.9%, P <0.01). Patients treated with cloxacillin presented higher rates of septic shock (25%, P = 0.033) and new-onset or worsening renal failure (47.3%, P = 0.024) with significantly higher rates of in-hospital mortality (38.5%, P = 0.017). One-year IE-related mortality and rate of relapses were similar between treatment groups. None of the treatments were identified as risk or protective factors. Conclusion: Our results suggest that cefazolin is a valuable option for the treatment of MSSA IE, without differences in 1-year mortality or relapses compared with cloxacillin, and might be considered equally effective