Plant growth-promoting and heavy metal-resistant Priestia and Bacillus strains associated with pioneer plants from mine tailings.

Open mine tailings dams are extreme artificial environments containing sizeable potentially toxic elements (PTEs), including heavy metals (HMs), transition metals, and metalloids. Furthermore, these tailings have nutritional deficiencies, including assimilable phosphorus sources, organic carbon, and combined nitrogen, preventing plant colonization. Bacteria, that colonize these environments, have mechanisms to tolerate the selective pressures of PTEs. In this work, several Priestia megaterium (formerly Bacillus megaterium), Bacillus mojavensis, and Bacillus subtilis strains were isolated from bulk tailings, anthills, rhizosphere, and endosphere of pioneer plants from abandoned mine tailings in Zacatecas, Mexico. Bacillus spp. tolerated moderate HMs concentrations, produced siderophores and indole-3-acetic acid (IAA), solubilized phosphates, and reduced acetylene in the presence of HMs. The strains harbored different PIB-type ATPase genes encoding for efflux pumps and Cation Diffusion Facilitator (CDF) genes. Moreover, nifH and nifD nitrogenase genes were detected in P. megaterium and B. mojavensis genomic DNA. They showed similarity with sequences of the beta-Proteobacteria species, which may represent likely horizontal transfer events. These Bacillus species precede the colonization of mine tailings by plants. Their phenotypic and genotypic features could be essential in the natural recovery of the sites by reducing the oxidative stress of HMs, fixing nitrogen, solubilizing phosphate, and accumulating organic carbon. These traits of the strains reflect the adaptations of Bacillus species to the mine tailings environment and could contribute to the success of phytoremediation efforts.

Ammonia-Oligotrophic and Diazotrophic Heavy Metal-Resistant Serratia liquefaciens Strains from Pioneer Plants and Mine Tailings.

Mine tailings are man-made environments characterized by low levels of organic carbon and assimilable nitrogen, as well as moderate concentrations of heavy metals. For the introduction of nitrogen into these environments, a key role is played by ammonia-oligotrophic/diazotrophic heavy metal-resistant guilds. In mine tailings from Zacatecas, Mexico, Serratia liquefaciens was the dominant heterotrophic culturable species isolated in N-free media from bulk mine tailings as well as the rhizosphere, roots, and aerial parts of pioneer plants. S. liquefaciens strains proved to be a meta-population with high intraspecific genetic diversity and a potential to respond to these extreme conditions. The phenotypic and genotypic features of these strains reveal the potential adaptation of S. liquefaciens to oligotrophic and nitrogen-limited mine tailings with high concentrations of heavy metals. These features include ammonia-oligotrophic growth, nitrogen fixation, siderophore and indoleacetic acid production, phosphate solubilization, biofilm formation, moderate tolerance to heavy metals under conditions of diverse nitrogen availability, and the presence of zntA, amtB, and nifH genes. The acetylene reduction assay suggests low nitrogen-fixing activity. The nifH gene was harbored in a plasmid of ∼60 kb and probably was acquired by a horizontal gene transfer event from Klebsiella variicola.

Review of Topical Sodium Heparin 1000 IU/g Gel in Symptomatic Uncomplicated Superficial Thrombophlebitis.

Heparin, a mixture of sulfated polymorphic polysaccharides (glycosaminoglycan) chains of variable lengths and weights and a natural anticoagulant, is widely used in medical practice to prevent intravascular blood coagulation. Heparin has demonstrated antithrombotic and anti-inflammatory activity, and it is mostly administered systemically (intravenously or subcutaneously) for primary or secondary prevention of venous thromboembolism after surgical interventions, or immobilized patients, or on short-term antithrombotic therapy of patients with atrial fibrillation who must undergo treatment. However, since systemic administration of heparin could be, in certain cases, linked to an increased risk of bleeding, topical heparin is widely used for the prevention and treatment of local symptoms of peripheral vascular disorders, such as venous insufficiency, varicose veins, or superficial thrombophlebitis. This review summarizes the main safety and efficacy characteristics of the topical formulation of Heparin in Gel form (1000 International Units of Heparin/g Gel) currently in use, which has demonstrated an excellent efficacy and tolerability profile in reducing signs and symptoms of peripheral vascular disease, e.g., varicose syndromes and their complications, phlebothrombosis, thrombophlebitis, superficial periphlebitis, varicose ulcers, for post-operative varicophlebitis, sequelae of saphenectomy, for traumas and contusions, local edemas and infiltrates, subcutaneous hematoma and for traumatic affections of musculotendinous and capsuloligamentous apparatuses.

3,3'-(Ethane-1,2-di-yl)bis-(3,4-dihydro-2H-1,3-benzoxazine).

The title compound, C(18)H(20)N(2)O(2), was prepared by Mannich-type reaction of phenol, ethane-1,2-diamine and formaldehyde. The heterocyclic rings adopt half-chair conformations. The acyclic methyl-ene groups attached to the N atoms are in an axial position. In the crystal, weak C-H⋯O hydrogen bonds link the mol-ecules into dimers. These dimers are further connected via C-H⋯π contacts.

3,3'-(Ethane-1,2-diyl)bis(6-meth-oxy-3,4-dihydro-2H-1,3-benzoxazine) mono-hydrate.

The asymmetric unit of the title compound, C(20)H(24)N(2)O(4)·H(2)O, contains one half-organic mol-ecule (an inversion centre generates the other half of the mol-ecule) and a half-mol-ecule of water (the O atom has site symmetry 2). The near planarity of the fused-benzene ring is illustrated by the very small deviations of all the atoms from the plane [largest deviation = 0.0092 (11) Å. The six-membered N,O-containing ring adopts a half-chair conformation. The observed N-CH(2) and CH(2)-O bond lengths can be correlated to the manifestation of an anomeric effect in the N-CH(2)-O unit. In the crystal, the mol-ecules are connected into zigzag chains parallel to [001] through O-H⋯N hydrogen bonds formed between the oxazinic N atom and the solvent water mol-ecule. The chains are consolidated by C-H⋯O inter-actions.

3,3'-(Ethane-1,2-di-yl)bis-(6-methyl-3,4-dihydro-2H-1,3-benzoxazine).

The asymmetric unit of the title compound, C(20)H(24)N(2)O(2), contains one half-mol-ecule, which is completed by inversion symmetry. In the crystal, mol-ecular chains are formed through non-classical C-H⋯O hydrogen bonds, formed between axial H atoms of the oxazine ring and a O atom of a neighboring mol-ecule.

The Mexican giant maize of Jala landrace harbour plant-growth-promoting rhizospheric and endophytic bacteria.

The giant landrace of maize Jala is a native crop cultured in Nayarit and Jalisco States in the occident of México. In this study, after screening 374 rhizospheric and endophytic bacteria isolated from rhizospheric soil, root, and seed tissues of maize Jala, a total of 16 bacterial strains were selected for their plant-growth-promoting potential and identified by 16S rRNA phylogenetic analysis. The isolates exhibited different combinations of phenotypic traits, including solubilisation of phosphate from hydroxyapatite, production of a broad spectrum of siderophores such as cobalt, iron, molybdenum, vanadium, or zinc (Co2+, Fe3+, Mo2 +, V5+, Zn2+), and nitrogen fixation capabilities, which were detected in both rhizospheric and endophytic strains. Additional traits such as production of 1-aminocyclopropane-1-carboxylate deaminase and a high-rate production of Indoleacetic Acid were exclusively detected on endophytic isolates. Among the selected strains, the rhizospheric Burkholderia sp., and Klebsiella variicola, and the endophytic Pseudomonas protegens significantly improved the growth of maize plants in greenhouse assays and controlled the infection against Fusarium sp. 50 on fresh maize cobs. These results present the first deep approach on handling autochthonous microorganisms from native maize with a potential biotechnological application in sustainable agriculture as biofertilizers or biopesticides.

Demulsification of crude oil-in-water emulsions by means of fungal spores.

The present feature describes for the first time the application of spores from Aspergillus sp. IMPMS7 to break out crude oil-in-water emulsions (O/W). The fungal spores were isolated from marine sediments polluted with petroleum hydrocarbons. The spores exhibited the ability to destabilize different O/W emulsions prepared with medium, heavy or extra-heavy Mexican crude oils with specific gravities between 10.1 and 21.2°API. The isolated fungal spores showed a high hydrophobic power of 89.3 ± 1.9% and with 2 g of spores per liter of emulsion, the half-life for emulsion destabilization was roughly 3.5 and 0.7 h for extra-heavy and medium crude oil, respectively. Then, the kinetics of water separation and the breaking of the O/W emulsion prepared with heavy oil through a spectrofluorometric technique were studied. A decrease in the fluorescence ratio at 339 and 326 nm (I339/I326) was observed in emulsions treated with spores, which is similar to previously reported results using chemical demulsifiers.

Caracterización de un grupo de comités de ética en investigación en Colombia / Characterization of a Group of Research Ethics Committees in Colombia / Caracterização de um grupo de comitês de ética em pesquisa na Colômbia

Resumen En las últimas décadas, los ensayos clínicos controlados patrocinados por la industria farmacéutica han aumentado de manera considerable, lo cual ha llevado a que sea necesario un mayor control y acompañamiento por parte de las entidades reguladoras, y de los comités de ética, para garantizar el adecuado cumplimiento de las normas éticas establecidas y de las buenas prácticas clínicas en general. En Colombia, el Instituto Nacional de Vigilancia de Medicamentos y Alimentos (Invima), la entidad reguladora en el país, reglamenta y vigila el funcionamiento de la investigación clínica con medicamentos. En el 2008, esta entidad emitió la Resolución 2378, normatividad bajo la cual se establecen y regulan los diferentes actores de la investigación en Colombia, incluidos los comités de ética. Después de varios años de vigencia de esta norma, es necesario conocer si los comités de ética en investigación en Colombia funcionan de acuerdo con esta normativa, y determinar el estado de la implementación de lo solicitado en la regulación. Con este objetivo se diseñó una encuesta para ser respondida en forma voluntaria y se obtuvo respuesta de 25 de los 69 comités certificados en Colombia. El análisis fue posible en 22 de ellos cuya información estaba completa. En comparación con estudios anteriores, se observaron cambios favorables en el desarrollo y la organización de acuerdo con la norma actual propuesta.

Abstract In the last decades, controlled clinical trials sponsored by the pharmaceutical industry have increased considerably. This has led to the need for greater control and assistance by regulators and ethics committees to ensure appropriate compliance with established ethical standards and good clinical practices in general. In Colombia, the National Food and Drug Surveillance Institute (INVIMA), the regulator in the country, controls and monitors the operation of clinical research with drugs. In 2008, this entity issued Resolution 2378, which provides and regulates research actors in Colombia, including ethics committees. After being in force for several years, it is necessary to know whether research ethics committees in Colombia operate in accordance with this regulation and to determine the status of implementation of the requirements therein. For this purpose, a survey was designed to be voluntarily answered and a response was obtained from 25 of the 69 certified committees in Colombia. Twenty-two of them could be analyzed because their information was complete. Compared with previous studies, favorable changes in development and organization were observed in accordance with the current proposed regulation.

Resumo Nas últimas décadas, os ensaios clínicos controlados patrocinados pela indústria farmacêutica aumentaram consideravelmente, o que levou à necessidade de um maior controle e acompanhamento por entidades reguladoras e comitês de ética, para garantir o cumprimento adequado de normas éticas estabelecidas e boas práticas clínicas em geral. Na Colômbia, o Instituto Nacional de Vigilância de Medicamentos e Alimentos (Invima, na sigla em espanhol), órgão regulador no país, regulamenta e monitora o funcionamento da pesquisa clínica com medicamentos. Em 2008, essa entidade emitiu a Resolução 2378, que estabelece e regulamenta os diferentes atores da pesquisa na Colômbia, incluindo os comitês de ética. Depois de vários anos de vigência dessa norma, é necessário saber se os comitês de ética em pesquisa da Colômbia trabalham de acordo com este regulamento e determinar o estado da implementação do que é solicitado no regulamento. Com esse objetivo, uma pesquisa foi elaborada para ser respondida voluntariamente e uma resposta foi obtida de 25 dos 69 comitês certificados na Colômbia. A análise foi possível em 22 deles, cuja informação estava completa. Em comparação com estudos anteriores, mudanças favoráveis no desenvolvimento e organização foram observadas de acordo com a norma atual proposta.

Blended Learning y estilos de aprendizaje en estudiantes universitarios del área de la salud / Blended learning and learning styles in university students of the health areas

El presente artículo describe el desarrollo de un proceso de investigación que dio cuenta del favorecimiento de los estilos de aprendizaje como consecuencia de la interacción de estudiantes universitarios pertenecientes al área de la salud, a través de un ambiente blended learning diseñado desde una perspectiva de aprendizaje experiencial. La investigación se llevó a cabo en dos fases con un enfoque mixto. La primera, a través de una aproximación cuantitativa con un diseño descriptivo y transversal, cuyo propósito fue identificar los estilos de aprendizaje y su correlación con el rendimiento académico. La segunda fase, de corte cualitativo se desarrolló como un estudio de caso, cuyo objetivo fue analizar la percepción de satisfacción y las dificultades de los estudiantes con relación a la estrategia blended learning diseñada. Las conclusiones de la investigación hacen especial énfasis en las relaciones entre estilos de aprendizaje, rendimiento académico, satisfacción y factores que limitan el aprendizaje.

This article described the development of a research study that revealed the encouragement of learning styles as a result of the interaction among university students from a health area, through the blended learning environment designed from an experiential learning perspective. This research study had two phases: the first one was a quantitative approach based on a descriptive cross-sectional design to identify the learning styles and their correlation with academic performance. The second one was qualitative-oriented and developed as a case study to analyze the perception of satisfaction of and the difficulties faced by the students in relation to this blended learning strategy. The final conclusions made special emphasis on the relationships among the learning styles, the academic performance, the level of satisfaction and the factors restricting the learning process.

Patología benigna de laringe en docentes y cantantes / Benign diseases of larynx in teachers and singers

La disfonía es uno de los motivos de consulta más frecuente en docentes y cantantes, quienes presentan un índice alto de patología de voz. Son muy pocos los estudios en nuestro medio acercade la patología laríngea en la población descrita a pesar de conocerse su alta probabilidad de lesiones laríngeas. Objetivo: Describir las características estroboscópicas y factores de riesgoasociados en pacientes con abuso de voz (cantantes y docentes) que consultaron entre agosto de 2006 y noviembre de 2009 por disfonía crónica y se encontraron con lesiones benignas de laringe. Materiales y métodos: Se realizó un estudio de corte transversal, de tipo retrospectivo. Resultados:365 pacientes fueron incluidos en el estudio, 302 docentes y 63 cantantes. Se describen la distribución de género, la frecuencia fundamental, los hallazgos glóticos la periodicidad, la simetría, ondamucosa y factores de riesgo asociados. Conclusión: La frecuencia de presentación de patología laríngea en pacientes con abuso vocal, en nuestro medio es muy alta. Encontramos cambios asociados a RGE y los nódulos vocales como principales diagnósticos en este grupo de pacientes. De igualmanera es mayor la presencia de patología laríngea en personas con varios años de desarrollo de laprofesión. Factores como exposición a polvo de tiza, cigarrillo, estrés, falta de educación vocal, periodos prolongados de sobreesfuerzo vocal, llevan a un aumento en la presentación de este tipo de patología.

The dysphonia is one of the most common reasons for consultation on teachers and singers, who have a high index of voice pathology. There are very few studies in our country about laryngeal pathology in this population in spite of knowing their high probability of laryngeal lesions. Objective: Todescribe the stroboscopic features and associated risk factors in patients with voice abuse (singers and teachers) who consulted between August 2006 and November 2009 for chronic dysphonia and being found with benign lesions of the larynx. Materials and methods: We conducted a cross-sectional,retrospective study. Results: 365 patients were included in the study, 302 teachers and 63 singers. We describe the gender distribution, the fundamental frequency, the glottis findings, periodicity, symmetry, mucosal wave and associated risk factors. Conclusion: The frequency of laryngeal pathology insingers and teachers in our area is very high. We found changes associated with GERD and vocal nodules as primary diagnosis in this patient group. Similarly, we found that there is a greater presence of laryngeal pathology in people with several years of development of the profession. Factors such as chalk dust exposure, smoking, stress, lack of vocal education, prolonged periods of vocal overuse, leadto an increase in the presence of this type of pathology.