435 resultados para Synechocystis PCC 6803
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A polyhydroxybutyrate (PHB) producing cyanobacteria was converted through hydrothermal liquefaction (HTL) into propylene and a bio-oil suitable for advanced biofuel production. HTL of model compounds demonstrated that in contrast to proteins and carbohydrates, no synergistic effects were detected when converting PHB in the presence of algae. Subsequently, Synechocystis cf. salina, which had accumulated 7.5wt% PHB was converted via HTL (15% dry weight loading, 340°C). The reaction gave an overall propylene yield of 2.6%, higher than that obtained from the model compounds, in addition to a bio-oil with a low nitrogen content of 4.6%. No propylene was recovered from the alternative non-PHB producing cyanobacterial strains screened, suggesting that PHB is the source of propylene. PHB producing microorganisms could therefore be used as a feedstock for a biorefinery to produce polypropylene and advanced biofuels, with the level of propylene being proportional to the accumulated amount of PHB.
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OBJECTIVE: To compare the overall performance of specially trained neonatal nurses acting autonomously, unsupervised, and without a protocol with specialist registrars when weaning neonates from mechanical ventilation.
DESIGN: Prospective, randomized, controlled trial.
SETTING: A single neonatal intensive care unit.
PATIENTS: Neonates requiring conventional mechanical ventilation (n = 50).
INTERVENTIONS: Infants on conventional ventilation were randomly assigned to receive either nurse-led (n = 25) or registrar-led (n = 23) weaning. A total of 48 infants completed the study (two infants in the registrar group were excluded when their parents withdrew consent).
MEASUREMENTS AND MAIN RESULTS: The main outcome measure, median weaning time, was 1200 mins (95% confidence interval [CI], 621-1779 mins) in the nurse group and 3015 mins (95% CI, 2650-3380 mins) in the registrar group (p = .0458). The median time from treatment assignment to the first ventilator change was 60 mins (95% CI, 52-68 mins) in the nurse group and 120 mins (95% CI, 103-137 mins) in the registrar group (p = .35). On average, the nurses made ventilator changes every 4.5 hrs (95% CI, 2.9-6 hrs) and the registrars every 7.2 hrs (95% CI, 5.4-9 hrs; p = .003). The median number (range) of backward steps taken per infant was 0 (0-5 steps) in the nurse group and 1 (0-5 steps) in the registrar group (p = .019).
CONCLUSIONS: The findings of this study suggest that additional domains of neonatal critical care could be reviewed for their potential transfer to appropriately prepared nurses.
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The purpose of this project was to evaluate the location and quantities of debonding in selected portland cement concrete (PCC) overlays. The project entailed an infrared thermographic survey and a ground penetrating radar survey of the PCC overlays to locate areas of debonding between the overlays and the original pavement. An infrared scanner is capable of locating these areas because of the temperature differential which is established between bonded and debonded areas under certain environmental conditions. A conventional video inspection of the top surface of the pavement was also completed in conjunction with the infrared thermographic survey to record the visual condition of the pavement surface. The ground penetrating radar system is capable of locating areas of debonding by detecting return wave forms generated by changes in the dielectric properties at the PCC overlay original pavement interface. This report consists of two parts; a text and a set of plan sheets. The text summarizes the procedures, analyses and conclusions of the investigation. The plan sheets locate specific areas of debonding, as identified through field observations.
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Portland cement concrete (PCC) pavement undergoes repeated environmental load-related deflection resulting from temperature and moisture variations across the pavement depth. This phenomenon, referred to as PCC pavement curling and warping, has been known and studied since the mid-1920s. Slab curvature can be further magnified under repeated traffic loads and may ultimately lead to fatigue failures, including top-down and bottom-up transverse, longitudinal, and corner cracking. It is therefore important to measure the “true” degree of curling and warping in PCC pavements, not only for quality control (QC) and quality assurance (QA) purposes, but also to achieve a better understanding of its relationship to long-term pavement performance. In order to better understand the curling and warping behavior of PCC pavements in Iowa and provide recommendations to mitigate curling and warping deflections, field investigations were performed at six existing sites during the late fall of 2015. These sites included PCC pavements with various ages, slab shapes, mix design aspects, and environmental conditions during construction. A stationary light detection and ranging (LiDAR) device was used to scan the slab surfaces. The degree of curling and warping along the longitudinal, transverse, and diagonal directions was calculated for the selected slabs based on the point clouds acquired using LiDAR. The results and findings are correlated to variations in pavement performance, mix design, pavement design, and construction details at each site. Recommendations regarding how to minimize curling and warping are provided based on a literature review and this field study. Some examples of using point cloud data to build three-dimensional (3D) models of the overall curvature of the slab shape are presented to show the feasibility of using this 3D analysis method for curling and warping analysis.
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Common people and books seem to be opposed terms. On the one hand books are usually the symbol of culture; on the other hand the culture of the Volk did not used to be a literate one. This article reviews the relation between both terms from the 16th to the 19th Century and shows that it is not possible to separate both terms, because the different ways of appropriation allow people to 'read' books in many different ways.
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La higiene de los alimentos para el consumo humano es un derecho que tienen todas las personas, pues esto les evita daños a la salud. La incidencia de las enfermedades por transmisión alimentaria ha ido en aumento, y pueden llevar en muchos casos incluso hasta la muerte. Asimismo, hay efectos negativos en el deterioro de los alimentos, significan costos y pérdidas económicas para los países. Estas son razones por las que se deben tener sistemas que aseguren la higiene de los alimentos. Los riesgos alimentarios pueden ser de tipo microbiológico, residuos de plaguicidas, utilización inadecuada de los aditivos alimentarios, contaminantes químicos, incluidas las toxinas biológicas, adulteraciones. Así también se pueden incluir organismos genéticamente modificados, alérgenos, residuos de medicamentos veterinarios y hormonas. Por estas razones, es necesario un control eficaz de la higiene para evitar las enfermedades y por el daño en alimentos a la economía de un país. Cada vez que un consumidor paga por un alimento, bien sea para consumo inmediato o para un proceso de cocción y luego ser ingerido, espera que lo puede consumir sin ningún peligro, ya que confía en que las autoridades sanitarias encargadas en cada uno de los eslabones de la cadena alimenticia (Finca, Planta, Expendio, Comercio, Transporte) han desarrollado actividades que le den la garantía al consumidor de pagar por el producto e ingerirlo sin pensar en que afectará su salud. Hoy en día, se observa, como sigue en aumento los índices de Enfermedades Transmitidas por Alimentos (ETA´s), mientras que, los esfuerzos por disminuir e identificar las fallas en el aseguramiento de la inocuidad de los alimentos en todo el proceso son insuficientes. El Gobierno de Nicaragua, ha tomado conciencia y se está preparando para los próximos desafíos que presentará el comercio mundial en cuanto a garantizar productos de alta calidad e inocuidad. Por lo tanto, el MAG para mejorar y asegurar la inocuidad de los productos de origen animal y vegetal se ha basado en la implementación del sistema HACCP cuyo enfoque principal es la seguridad alimentaria y nutricional, en conjunto con la implementación de los programas prerrequisitos como son las Buenas Prácticas Agrícolas (BPA), Buenas Prácticas de manufactura (BPM), Programas de Operación y Sanitización (SOP's).(Picado, 2002).El objetivo del presente estudio de caso fue: Contrastar la aplicación de las normas Sistemas de Análisis de Peligro y Puntos Críticos de Control (HACCP) en el periodo 2014 – 2015, en el MATADERO NICA BEEF PACKERS S.A, que funciona en el municipio de Condega, Departamento de Estelí, Nicaragua. Para alcanzar el objetivo se aplicó una metodología comparativa entre un estudio anterior y las nuevas realidades generadas en la empresa, apoyándonos para tal efecto de técnicas e instrumentos aplicados por la ciencia como son: la entrevista, la observación, el análisis documental, y programas de aplicación Microsoft Word y Excel 2010, las que fueron utilizadas pertinentemente en su momento, permitiendo el procesamiento de datos y su posterior análisis. El punto de partida de este proceso investigativo fue la búsqueda de información relacionada al objeto de estudio, determinándose los tres puntos críticos de control y las variables que influyen en el fenómeno estudiado.. Las variables tomadas en cuenta fueron: Buenas prácticas de manufacturación, Procedimientos operativos estandarizados de Higiene, Análisis de riesgos, identificación y control de puntos críticos (HACCP). En lo concerniente a la primer variable las buenas prácticas de manufactura que realiza el personal de la empresa, se cumplen en un 91 % en ambos estudios, destacándose en forma ascendente las condiciones de edificio con el 94% y el personal con 93%; la segunda variable referida a los Procedimientos Operacionales Estándares (POE), se cumplen en un 88.65 %, ubicándose en un lugar privilegiado la salud de los trabajadores al tener 99% de cumplimiento. En promedio estos prerrequisitos generales se cumplen en un 89.82 %. La tercera variable las acciones correctivas de los PCC del sistema HACCP presentaron un 95.22% de cumplimiento, mostrando así que los equipos de trabajo de la empresa tienen un alto grado de conocimiento y la práctica requerida para las labores que realizan; en esta última sobresale el PCC N°2 que en cuanto a intervención antimicrobiano tuvo el 100% de cumplimiento, y un rango aceptable en la concentración de la solución de ácido orgánico de 1.5 a 2% y pH entre 3 y 4.4 unidades después del rociado,. En el PCC N°3 relacionada a la etapa de enfriamiento, se está cumpliendo con las normas establecidas en el reglamento HACCP, manteniendo temperatura de canales ≤ 8.33333 Grados Celsius, y 24 horas de refrigeración, impidiendo todas estas aplicaciones el desarrollo de bacterias patógenas.
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The work presented herein covers a broad range of research topics and so, in the interest of clarity, has been presented in a portfolio format. Accordingly, each chapter consists of its own introductory material prior to presentation of the key results garnered, this is then proceeded by a short discussion on their significance. In the first chapter, a methodology to facilitate the resolution and qualitative assessment of very large inorganic polyoxometalates was designed and implemented employing ion-mobility mass spectrometry. Furthermore, the potential of this technique for ‘mapping’ the conformational space occupied by this class of materials was demonstrated. These claims are then substantiated by the development of a tuneable, polyoxometalate-based calibration protocol that provided the necessary platform for quantitative assessments of similarly large, but unknown, polyoxometalate species. In addition, whilst addressing a major limitation of travelling wave ion mobility, this result also highlighted the potential of this technique for solution-phase cluster discovery. The second chapter reports on the application of a biophotovoltaic electrochemical cell for characterising the electrogenic activity inherent to a number of mutant Synechocystis strains. The intention was to determine the key components in the photosynthetic electron transport chain responsible for extracellular electron transfer. This would help to address the significant lack of mechanistic understanding in this field. Finally, in the third chapter, the design and fabrication of a low-cost, highly modular, continuous cell culture system is presented. To demonstrate the advantages and suitability of this platform for experimental evolution investigations, an exploration into the photophysiological response to gradual iron limitation, in both the ancestral wild type and a randomly generated mutant library population, was undertaken. Furthermore, coupling random mutagenesis to continuous culture in this way is shown to constitute a novel source of genetic variation that is open to further investigation.
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A doença cérebro-cardiovascular é uma realidade com taxas de prevalência preocupantes, onde a Hipertensão Arterial (HTA) apresenta-se como fator de risco primário no desenvolvimento daquela. Assim a adesão à terapêutica farmacológica da HTA é um fator importante para a redução da morbilidade e mortalidade associada às doenças cérebro-cardiovasculares, como o Enfarte Agudo do Miocárdio. A Enfermagem torna-se, assim, a ciência da saúde com bastante enfoque na promoção da saúde e prevenção de complicações em saúde. O objetivo compreende a identificação das estratégias utilizadas pela equipa multidisciplinar na promoção da adesão à terapêutica farmacológica, da pessoa com HTA em ambulatório, e como as mesmas se refletem na prática de cuidados. Nesta Revisão Sistemática da Literatura a formulação da questão de pesquisa está orientada pelo acrónimo PCC, envolvendo os seus constituintes: População – Pessoa com HTA; Conceito – Adesão à terapêutica farmacológica; Contexto – Ambulatório. Estabeleceram-se como critérios de inclusão Pessoas adultas com mais de 18 anos, com HTA diagnosticada, sob tratamento farmacológico, que não se encontrem internadas em unidades hospitalares. Tipos de Estudos primários, publicados na língua portuguesa, inglesa e espanhola num período estabelecido entre janeiro de 2005 e fevereiro de 2016 e que investigam o impacto de intervenções da equipa multidisciplinar de saúde, na adesão à terapêutica farmacológica da HTA. Os estudos apresentam como resultados a efetiva diminuição da TA e aumento da AT farmacológica em que são definidas como estratégias a Melhoria de atitudes e crenças sobre a saúde, Aceitação da intervenção como apoio com relevância à alteração de comportamentos em saúde e à melhoria da adesão à terapêutica e respeito individual e de cuidados individualizados, com impacto na melhoria da adesão à terapêutica.
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El Salvador viene experimentando año con año cambios producto de la Reforma Educativa, y como parte de ese proceso se ha implementado la construcción del Proyecto Curricular de Centro (PCC) y del Proyecto Educativo Institucional (PEI ) siendo dentro de este ultimo donde se pueden encontrar Proyectos Complementarios y en estos surgen las “Tertulias Literarias dentro del Centro Escolar España”. Este proyecto nace como una iniciativa por combatir la apatía a la lectura, y tratar de hacer del Proceso de Enseñanza Aprendizaje un camino ameno e interesante para las alumnas de esta institución educativa. Todo proceso de cambio esta sometido a una diversidad de aspectos tanto positivos como negativos, es decir, factores a su favor o en su contra, y estos contribuirán o entorpecerán el proceso de transformación que se pretenda implementar. Así también dentro de estos, factores, se pueden encontrar las personas mismas que por la complejidad del comportamiento humano muchas veces se pueden tener inconvenientes en cualquier proceso de transformación. Para el caso especifico, de la presente investigación al hablar de transformación se habla de los cambios a operar en la rutina diaria que desarrollan los/as profesores / as, es decir, innovar, buscar una manera diferente de hacer las cosas con el objetivo de generar aprendizajes significativos en las alumnas del Centro Escolar objeto de la presente investigación.
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In recent years marine biotechnology has revealed a crucial role in the future of bioindustry. Among the many marine resources, cyanobacteria have shown great potential in the production of bioactive compounds with diverse applicability. The pharmacological potential of these organisms has been one of the most explored areas in particular its antibacterial, antifungal and anticancer potential. This work was based on the assessment of potential anticancer compound E13010 F 5.4 isolated from marine cyanobacteria strain Synechocystis salina LEGE 06099. Thus the aim of this work was to explore molecular and biochemical mechanisms underlying the bioactivity detected in human cancer cells, specifically in lines RKO colon carcinoma and HT-29. The isolation of the compound was performed from biomass obtained by large-scale culture. To obtain the compound fractionation was carried and confirmation and isolation performed by Nuclear Magnetic Resonance (NMR), Thin Layer Chromatography (TLC) and High-Performance Liquid Chromatography (HPLC). Cell viability assays were performed based on reduction of 3- (4,5-dimetiltiaziol-2-yl) -2,5-diphenyltetrazolium bromide (MTT) to assess the cytotoxic potential of the compound. From the battery of cell lines RKO (colon carcinoma), HT-29 (colorectal adenocarcinoma), MG-63 (osteosarcoma) and T47D (breast carcinoma) the cell lines RKO and HT-29 were selected for elucidation of mechanisms of cytotoxicity. For the elucidation of the mechanisms involved in cytotoxicity the cell lines RKO and HT29 were exposed to the compound. A genomic approach based in the mRNA expression of genes involved in apoptosis and cell cycle by Real-Time PCR and a proteomic approach based on the separation of proteins by two-dimensional electrophoresis (2DGE) was performed. For mRNA expression were selected the genes RPL8, HPRT1, VDAC, SHMT2, CCNE, CCNB1, P21CIP, BCL-2 and BAD and for proteomics isoelectric focussing between 3 – 10 and molecular weight of 19 – 117 kDa separated by polyacrylamide gels (2DGE). The MTT results confirmed the reduction of the cell viability. The RT-PCR results for the expression of genes studied were not yet fully elucidative. For the cell line RKO there was a significant reduction in the expression of the gene P21CIP, and a tendency for reduction in the BAD gene expression and for increased expression of gene CCNB1, pointing to an effort for cell proliferation. In HT-29 cell line, there was a tendency for increase in the expression of P21CIP and BAD, which may explain the reduction in cell viability. The 2DGE results indicate proteomic patterns with differentially altered spots in the treated and control cells with both qualitative and quantitative differences, and differences in response between the RKO and HT-29 cell lines.
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The response regulator RpaB (regulator of phycobilisome associated B), part of an essential two-component system conserved in cyanobacteria that responds to multiple environmental signals, has recently been implicated in the control of cell dimensions and of circadian rhythms of gene expression in the model cyanobacterium Synechococcus elongatus PCC 7942. However, little is known of the molecular mechanisms that underlie RpaB functions. In this study we show that the regulation of phenotypes by RpaB is intimately connected with the activity of RpaA (regulator of phycobilisome associated A), the master regulator of circadian transcription patterns. RpaB affects RpaA activity both through control of gene expression, a function requiring an intact effector domain, and via altering RpaA phosphorylation, a function mediated through the N-terminal receiver domain of RpaB. Thus, both phosphorylation cross-talk and coregulation of target genes play a role in the genetic interactions between the RpaA and RpaB pathways. In addition, RpaB∼P levels appear critical for survival under light:dark cycles, conditions in which RpaB phosphorylation is environmentally driven independent of the circadian clock. We propose that the complex regulatory interactions between the essential and environmentally sensitive NblS-RpaB system and the SasA-RpaA clock output system integrate relevant extra- and intracellular signals to the circadian clock.
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El VI Congreso del Partido Comunista de Cuba introdujo una nueva agenda económica que el Gobierno llama la actualización del modelo socialista. Muchos piensan que en esencia se trata de una serie de reformas y reducen su importancia a su dimensión económica. Esta monografía busca explicar la actualización aplicando el análisis de sistemas-mundo de Immanuel Wallerstein, aportando una interpretación no convencional del fenómeno. Se puntualizará en las variables de poder y en los actores políticos que han determinado la nueva política económica: el Partido Comunista de Cuba (PCC) y las Fuerzas Armadas Revolucionarias (FAR). Ambos conforman lo que Wallerstein denomina un movimiento antisitémico. El argumento principal es que el movimiento ha puesto en marcha las reformas buscando fortalecer el Estado y así garantizar su supervivencia al consolidar su posición como el competidor único del poder estatal. Como se verá, estas metas han llevado al movimiento a sacrificar parte de su naturaleza antisistémica.
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We report an efficient methodology for the direct oxidative esterification of primary alcohols to diether-esters using pyridinium chlorochromate (PCC). Numerous studies were carried out to probe the reaction mechanism and at the same time optimize the reaction conditions. The reaction could be conducted with 1 equivalent of PCC and 1 equivalent of BF3 center dot OEt2. Indications based on literature precedent were that the reaction may proceed via a sequential alcohol oxidation to the aldehyde followed by a putative Cr or boron catalyzed Claisen-Tishchenko-type reaction. Using this efficient methodology, we synthesized a family of novel diether-esters in very good yields; some of these molecules were subsequently tested against both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). In addition, we also disclose a new synthetic strategy for the synthesis of lactam macrocycles with potential biological activity. This methodology included the regioselective borylation of the ester substrate and a subsequent Suzuki-Miyaura coupling to obtain the desired lactam macrocycle.
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O presente trabalho teve como objetivo determinar a produtividade agrícola e a qualidade tecnológica do caldo das variedades da cana-de-açúcar, submetidas a diferentes regimes hídricos. O delineamento experimental foi em blocos ao acaso com três repetições em parcelas subdivididas, com três variedades RB855156, RB835486 e RB867515 (parcela), e sete regimes hídricos correspondendo a 0, 7, 17, 36, 46, 75 e 100% da ETc (subparcela). Foram avaliadas as características de produção: comprimento do entrenó (CE), peso do colmo (PC), número de perfilhos por hectare e produtividade; e tecnológicos do caldo: ºBrix do caldo, Pol do caldo (Teor de sacarose), pureza (PZA), AR (teor de açúcares redutores do caldo), ARC (açúcares redutores da cana), fibras, Pol da cana (PCC), açúcares totais recuperáveis (ATR) e o valor da megagrama da cana (VMgC). O máximo de produtividade da cana-de-açúcar foi de 182,31 Mg ha-1 registrado com irrigação equivalente a 69,01% da ETc; A cana-de-açúcar cultivada com irrigação equivalente a 75% da ETc não proporcionou diferença significativa para a qualidade industrial das variedades testadas em relação ao cultivo em sequeiro (0% da ETc). Não houve diferença significativa para os valores do teor de açúcares redutores (AR), açúcares redutores da cana (ARC) e a pureza do caldo (PZA) entre as variedades. ABSTRACT: This work aimed to determine the agricultural productivity and the technological quality of the juice of the sugarcane varieties, which were submitted to different hydrological regimes. The experimental design was made in randomized blocks with three repetitions in subdivided plots, with three varieties: RB855156, RB835486 and RB867515 (plot), and seven hydrological regimes corresponding to 0, 7, 17, 36, 46, 75 and 100% of ETc (subplot). The following production characteristics were evaluated: length of internode (LI), stem weight (SW), number of tillers per hectare and productivity; and technological components of the juice: ºBrix of the juice, Pol of the juice (sucrose levels), purity (PTY), RS (amount of reducing sugars of the juice), RSC (reducing sugars of the sugarcane plant), fibers, Pol of the sugarcane plant (CPP), total retrievable sugars (TRS) and the value of the sugarcane megagram (Mg). The maximum productivity of sugarcane was 182.31 Mg ha-1, which was registered with irrigation equivalent to 69.01% of ETc. The sugarcane cultivated with irrigation equivalent to 75% of ETc did not provide significant difference for the industrial quality of varieties tested in relation to the non-irrigated cultivation (0% of ETc). There was no significant difference for the values of reducing sugars (RS), the reducing sugars of the sugarcane plant (RSC) and the juice purity (PTY) among varieties.
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O objetivo desse trabalho foi avaliar dois métodos de laboratório para a determinação da condutividade hidráulica do solo saturada (Ko) conhecidos como Permeâmetro de carga constante (PCC) e Permeâmetro de carga decrescente (PCD), com o intuito de verificar sua aplicabilidade e variabilidade em solos amazônicos.