Saponinas antifúngicas de Swartzia langsdorffii

Chromatographic fractionation of the EtOH extract from the leaves of Swartzia langsdorffii afforded the pentacyclic triterpenes oleanolic acid and lupeol, and two saponins: oleanolic acid 3-sophoroside and the new ester 3-O-b-D-(6'-methyl)-glucopyranosyl-28-O-b-D-glucopyranosyl-oleanate. Their structures were elucidated from spectral data, including 2D NMR and HRESIMS experiments. Antifungal activity of all isolated compounds was evaluated, using phytopathogens Cladosporium cladosporioides and C. sphaerospermum, and human pathogens Candida albicans, C. krusei, C. parapsilosis and Cryptococcus neoformans.

Rendimento térmico e emissões de contaminantes atmosféricos de gasolinas formuladas com etanol, MBTE e TAEE

The specific consumption and carbon monoxide (CO) and nitrogen oxide (NO) emissions from gasolines formulated with ethanol, methyl tert-butyl ether (MTBE) and tert-amyl ethyl ether (TAEE) were evaluated in the rich, stoichiometric and lean-burn regions during the operation of an Otto-cycle engine. The use of ethanol as an additive presented high specific consumption, while gasoline formulated with TAEE showed low specific consumption with the engine operating under lean-burn conditions. The ethers evaluated here presented a low percentage of CO in the rich-burn region when compared with ethanol.

El Burnout percibido o sensación de estar quemado en profesionales sanitarios: prevalencia y factores asociados

Depending on the various models explaining the burnout syndrome, different questionnaires have been developed to asses this topic, the most widely-used is the Maslach Burnout Inventory (MBI). Moreover, in trying to asses this syndrome in a faster and more practical way, several authors have developed other instruments with fewer items. The present investigation aims: 1. Study the prevalence of burnout syndrome perceived using a simple measure of self-reported burnout, and to analyse its association with the scales of MBI. 2. Study demographic and work conditions associated with the perceived burnout. 3. Relate the burnout to personal and work evaluations. The sample consist of 6150 health professionals in Latin America (mainly from Argentina but with representation from Mexico, Ecuador, Peru, Colombia, Uruguay, Guatemala and Spain, among others. The mean age of the sample was 42.4 years, 52.7% were males. They were supplied with an online questionnaire through the health web page ”Intramed” in order to measure characteristics, perceptions and professional opinions. The MBI and a simple question to assess perceptions of burnout (Do you feel burnt out ?) was also included. The results indicated that 36.3% of the sample has the perception of “burnt out” or burnout . The perceived burnout is closely related to emotional exhaustion and is independent of depersonalisation. The burnout is associated with the perceived sense of personal and family deterioration due to working conditions, and the idea of abandoning the profession

Retroalimentación docencia-asistencia-docencia: estudio sobre burnout en enfermeras de salud mental como estrategia de innovación y calidad docente

El síndrome de burnout se considera una vulnerabilidad en las profesiones de ayuda. La escasez de publicaciones sobre esta formación, orientó la creación de una asignatura optativa en el Grado de Enfermería de la Universidad de Barcelona (UB) en el curso 2009-2010. Igualmente, produjo interés por explorar esta temática en enfermeras asistenciales de salud mental cuya disciplina aborda la gestión del estrés. Se presenta un estudio descriptivo, transversal y de correlación, en una cohorte de 73 enfermeras que trabajaban en servicios asistenciales de salud mental en el año 2011. Los objetivos pretenden identificar si la muestra estudiada presenta afectación del síndrome de burnout y relacionar los resultados con las estrategias que dichas enfermeras declaran utilizar para hacer frente a las emociones negativas atribuidas a su trabajo. El instrumento empleado es el Maslach Burnout Inventory (MBI), una pregunta abierta y variables sociodemográficas y de salud. Los resultados indican que presentó burnout el 2,7% de la muestra estudiada junto con un nivel medio de despersonalización. Además presentan baja realización personal quienes trabajaban en unidades de enfermos crónicos. El cansancio emocional resulto mayor en mujeres que en hombres y esta presente en personal con contrato fijo y en quienes causaron baja en los dos últimos años. En general, se observa falta de formación y apoyo formal para gestionar el estrés en la muestra estudiada. Se concluye que la formación sobre burnout en el Grado de Enfermería, podría favorecer la gestión del estrés y prevenir su cronicidad hacia la desmotivación y el absentismo laboral.

Retroalimentación docencia-asistencia-docencia: estudio sobre burnout en enfermeras de salud mental como estrategia de innovación y calidad docente

El síndrome de burnout se considera una vulnerabilidad en las profesiones de ayuda. La escasez de publicaciones sobre esta formación, orientó la creación de una asignatura optativa en el Grado de Enfermería de la Universidad de Barcelona (UB) en el curso 2009-2010. Igualmente, produjo interés por explorar esta temática en enfermeras asistenciales de salud mental cuya disciplina aborda la gestión del estrés. Se presenta un estudio descriptivo, transversal y de correlación, en una cohorte de 73 enfermeras que trabajaban en servicios asistenciales de salud mental en el año 2011. Los objetivos pretenden identificar si la muestra estudiada presenta afectación del síndrome de burnout y relacionar los resultados con las estrategias que dichas enfermeras declaran utilizar para hacer frente a las emociones negativas atribuidas a su trabajo. El instrumento empleado es el Maslach Burnout Inventory (MBI), una pregunta abierta y variables sociodemográficas y de salud. Los resultados indican que presentó burnout el 2,7% de la muestra estudiada junto con un nivel medio de despersonalización. Además presentan baja realización personal quienes trabajaban en unidades de enfermos crónicos. El cansancio emocional resulto mayor en mujeres que en hombres y esta presente en personal con contrato fijo y en quienes causaron baja en los dos últimos años. En general, se observa falta de formación y apoyo formal para gestionar el estrés en la muestra estudiada. Se concluye que la formación sobre burnout en el Grado de Enfermería, podría favorecer la gestión del estrés y prevenir su cronicidad hacia la desmotivación y el absentismo laboral.

Kurkistus matemaatikon olan yli

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A brief introduction to molecular orbital theory of simple polyatomic molecules for undergraduate chemistry students

A simple, four-step method for better introducing undergraduate students to the fundamentals of molecular orbital (MO) theory of the polyatomic molecules H2O, NH3, BH3 and SiH4 using group theory is reported. These molecules serve to illustrate the concept of ligand group orbitals (LGOs) and subsequent construction of MO energy diagrams on the basis of molecular symmetry requirements.

Tropical biodiversity: has it been a potential source of secondary metabolites useful for medicinal chemistry?

The use of natural products has definitely been the most successful strategy in the discovery of novel medicines. Secondary metabolites from terrestrial and marine organisms have found considerable use in the treatment of numerous diseases and have been considered lead molecules both in their natural form and as templates for medicinal chemistry. This paper seeks to show the great value of secondary metabolites and emphasize the rich chemical diversity of Brazilian biodiversity. This natural chemical library remains understudied, but can be a useful source of new secondary metabolites with potential application as templates for drug discovery.

Brazilian vodkas have undetectable levels of ethyl carbamate

While in Europe vodka is mainly derived from potatoes or cereals, a large proportion of Brazilian vodka is likely obtained from sugarcane, which contains ethyl carbamate (EC) precursors. EC, in addition to several other contaminants and congeners, were investigated in 32 samples of Brazilian vodka. All samples complied with the Brazilian regulations for congeners and contaminants, having EC content below 0.01 mg/L (detection limit). These results are probably related to the processing of vodka, in particular the use of extractive and rectifying stainless steel distillation columns, which allow the production of high strength spirits with low levels of congeners and contaminants.

Formulation and characterization of poloxamer 407®: thermoreversible gel containing polymeric microparticles and hyaluronic acid

The influence of the composition and preparation method on the sol-gel transition temperature (Tsol-gel) and rheological response of poloxamer-based formulations was determined. Manual and more complex mechanical stirring were found to provide similar results. In addition, a linear dependence of Tsol-gel on the poloxamer content was observed in the range of concentrations analyzed, and a Poloxamer 407® concentration of 18% was selected. The addition of hyaluronic acid did not lead to significant changes in the Tsol-gel values. In contrast, the addition of microparticles caused a reduction in Tsol-gel without a significant reduction in gel strength, and pseudoplastic characteristics were observed, indicating that a thermoreversible gel was obtained with a rheology suitable for application in the treatment of burn wounds.

Metabolômica, uma abordagem otimizada para exploração da biodiversidade brasileira: estado da arte, perspectivas e desafios

Brazilian biodiversity is a colossal source of secondary metabolites with remarkable structural features, which are valuable in further biodiscovery studies. In order to fully understand the relations and interactions of a living system with its surroundings, efforts in natural product chemistry are directed toward the challenge of detecting and identifying all the molecular components present in complex samples. It is plausible that this endeavor was born out of recent technological sophistication in secondary metabolite identification with sensitive spectroscopic instruments (MS and NMR) and higher resolving power of chromatographic systems, which allow a decrease in the amount of required sample and time to acquire data. Nevertheless, the escalation of data acquired in these analyses must be sorted with statistical and multi-way tools in order to select key information. Chromatography is also of paramount importance, more so when selected compounds need to be isolated for further investigation. However, in the course of pursuing a "greener" environment, new policies, with an aim to decrease the use of energy and solvents, are being developed and incorporated into analytical methods. Metabolomics could be an effective tool to answer questions on how living organisms in our huge biodiversity work and interact with their surroundings while also being strategic to the development of high value bio-derived products, such as phytotherapeutics and nutraceuticals. The incorporation of proper phytotherapeutics in the so-called Brazilian Unified Health System is considered an important factor for the urgent improvement and expansion of the Brazilian national health system. Furthermore, this approach could have a positive impact on the international interest toward scientific research developed in Brazil as well as the development of high value bio-derived products, which appear as an interesting economic opportunity in national and global markets. Thus, this study attempts to highlight the recent advances in analytical tools used in detection of secondary metabolites, which can be useful as bioproducts. It also emphasizes the potential avenues to be explored in Brazilian biodiversity, known for its rich chemical diversity.

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Synthesis and characterization of activated carbon fibers from Kevlar

Kevlar [poly (p-phenilylene terephtalamide)], was used as a precursor in the preparation of activated carbon fibers. For this intention, physical and chemical activations were carried out. Activated fibers were physically prepared from the carbonization of the Kevlar and its later activation with CO2 and steam of water, by the other hand; the chemically activated fibers were obtained by means of the impregnation of the material with phosphoric acid and their later carbonization. Different conditions were used and preliminary analyses of the precursor were taken into account (TGA-DTA / IR). The resulting fibers were characterized by N2 (77K) adsorption, infrared spectroscopy, SEM, and immersion calorimetry. Yields and Burn off were also evaluated. The results shows that if you want to synthesize activated carbon fibers from Kevlar strong conditions respect to the commonly used such as water steam, high phosphoric acid concentrations and methods of impregnation are the ones who allows the development of optimal surface areas and pore volumes.

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