Efficient production of fatty acid methyl esters by a wastewater-isolated microalgae-yeast co-culture.

Improving the competitiveness of biodiesel production by microalgae cultures requires the application of several strategies to obtain a high content of lipids, rapid biomass growth and a capacity to adapt to different kinds of environment, with the aim of using non-renewable nutrient sources. Therefore, the use of an individual indigenous microalgae strain or a consortium from natural or anthropogenic sites is now considered an alternative for biofuel production. This study examined the temporal behaviour of secondary metabolites produced by a native microalgae and yeast consortium isolated from wastewater, which was characterized by a genetic identification method based on the MiSeq system. The predominant species in the consortium was Scenedesmus obliquus, representing 68% of the organisms. In addition, the consortium contained a number of yeast species, including Candida pimensis (43%), Arthroderma vanbreuseghemii (23%), Diaporthe aspalathi/Diaporthe meridionalis (25%) and Hericium americanum (3%). This indigenous co-culture of microalgae and yeast showed biomass productivity of 0.06 g l-1 day-1, with a content of 30% (w/w) carbohydrates, 4% (w/w) proteins and 55% (w/w) lipids. Transesterification of the extracted lipids produced fatty acid methyl esters (FAMEs), which were analysed by gas chromatography (GC). The FAMEs included methyl pentadecanoate (1.90%), cis-10-pentanedecanoic acid methyl ester (1.36%), methyl palmitate (2.64%), methyl palmitoleate (21.36%), methyl oleate (64.95%), methyl linolenate (3.83%) and methyl linolelaidate (3.95%). This composition was relevant for biodiesel production based on the co-culture of indigenous microalgae and yeast consortia.

[Concentration of titanium in respiratory tissue obtained from autopsies in Mexico city residents]. / Concentración de titanio en tejido respiratorio obtenido de autopsias en residentes de la ciudad de México.

OBJETIVOS.: To quantify the levels of titanium (Ti) in respiratory tissue obtained by autopsy in people who resided in Mexico City. MATERIALS AND METHODS.: An exploratory study was conducted in which 216 samples of respiratory tissue from pulmonary lobes and peribronchial lymph nodes were obtained from legal medical autopsies of 36 corpses with a minimum of two years of residence in Mexico City. Histopathological analyses of the samples were performed and the Ti existing in them was quantified by induction plasma coupled to atomic absorption spectrophotometry. RESULTS.: The amount of Ti in respiratory tissue was distributed between 0 micrograms of Ti in dry tissue (µg Ti/g ts) and 39.7 µg Ti/g ts; the presence of Ti was identified as distributed in up to six times a higher quantity in the lymph nodes than in pulmonary lobes. Cluster analysis showed that the sample consisted of four groups of individuals grouped according to the amount and distribution of Ti in the lower respiratory tract, age, body mass index, place and time of residence in Mexico City. CONCLUSIONS: . Due to the distribution pattern observed, Ti found in respiratory tissue samples may come from urban air; the amount of Ti in conjunction with other elements may be the cause of respiratory pathologies.

OBJETIVOS.: Cuantificar la cantidad de titanio (Ti) en tejido respiratorio obtenidas por autopsia en personas que residieron en la Ciudad de México. MATERIALES Y MÉTODOS.: Se realizó un estudio exploratorio en el cual se obtuvieron 216 muestras de tejido respiratorio de lóbulos pulmonares y nódulos linfáticos peribronquiales, procedentes de autopsias médico legales de 36 cadáveres con antecedente de haber residido un mínimo de dos años en la Ciudad de México. Se realizaron análisis histopatológicos de las muestras y se cuantificó el Ti existente en ellas mediante plasma de inducción acoplado a la espectrofotometría de absorción atómica. RESULTADOS.: La cantidad de Ti en tejido respiratorio se distribuyó entre 0 microgramos de Ti en tejido seco (µg Ti/g ts) y 39,7 µg Ti/g ts, se identificó la presencia de Ti distribuido hasta en seis veces mayor cantidad en los nódulos linfáticos que en lóbulos pulmonares. El análisis de conglomerados mostró que la muestra estaba conformada por cuatro grupos de individuos agrupados de acuerdo a la cantidad y distribución del Ti en el tracto respiratorio bajo, a la edad, índice de masa corporal, lugar y tiempo de residencia en la ciudad de México. CONCLUSIONES.: Debido al patrón de distribución observado el Ti encontrado en las muestras de tejido respiratorio podría provenir del aire urbano, la cantidad de Ti en conjunto con otros elementos podría ser causante de patologías respiratorias.

Concentración de titanio en tejido respiratorio obtenido de autopsias en residentes de la ciudad de México / Concentration of titanium in respiratory tissue obtained from autopsies in Mexico city residents

RESUMEN Objetivos. Cuantificar la cantidad de titanio (Ti) en tejido respiratorio obtenidas por autopsia en personas que residieron en la Ciudad de México. Materiales y métodos. Se realizó un estudio exploratorio en el cual se obtuvieron 216 muestras de tejido respiratorio de lóbulos pulmonares y nódulos linfáticos peribronquiales, procedentes de autopsias médico legales de 36 cadáveres con antecedente de haber residido un mínimo de dos años en la Ciudad de México. Se realizaron análisis histopatológicos de las muestras y se cuantificó el Ti existente en ellas mediante plasma de inducción acoplado a la espectrofotometría de absorción atómica. Resultados. La cantidad de Ti en tejido respiratorio se distribuyó entre 0 microgramos de Ti en tejido seco (µg Ti/g ts) y 39,7 µg Ti/g ts, se identificó la presencia de Ti distribuido hasta en seis veces mayor cantidad en los nódulos linfáticos que en lóbulos pulmonares. El análisis de conglomerados mostró que la muestra estaba conformada por cuatro grupos de individuos agrupados de acuerdo a la cantidad y distribución del Ti en el tracto respiratorio bajo, a la edad, índice de masa corporal, lugar y tiempo de residencia en la ciudad de México. Conclusiones. Debido al patrón de distribución observado el Ti encontrado en las muestras de tejido respiratorio podría provenir del aire urbano, la cantidad de Ti en conjunto con otros elementos podría ser causante de patologías respiratorias.

ABSTRACT Objetivos. To quantify the levels of titanium (Ti) in respiratory tissue obtained by autopsy in people who resided in Mexico City. Materials and Methods. An exploratory study was conducted in which 216 samples of respiratory tissue from pulmonary lobes and peribronchial lymph nodes were obtained from legal medical autopsies of 36 corpses with a minimum of two years of residence in Mexico City. Histopathological analyses of the samples were performed and the Ti existing in them was quantified by induction plasma coupled to atomic absorption spectrophotometry. Results. The amount of Ti in respiratory tissue was distributed between 0 micrograms of Ti in dry tissue (µg Ti/g ts) and 39.7 µg Ti/g ts; the presence of Ti was identified as distributed in up to six times a higher quantity in the lymph nodes than in pulmonary lobes. Cluster analysis showed that the sample consisted of four groups of individuals grouped according to the amount and distribution of Ti in the lower respiratory tract, age, body mass index, place and time of residence in Mexico City. Conclusions . Due to the distribution pattern observed, Ti found in respiratory tissue samples may come from urban air; the amount of Ti in conjunction with other elements may be the cause of respiratory pathologies.

Effects of prone positioning on lung protection in patients with acute respiratory distress syndrome.

RATIONALE: Positive end-expiratory pressure (PEEP) and prone positioning may induce lung recruitment and affect alveolar dynamics in acute respiratory distress syndrome (ARDS). Whether there is interdependence between the effects of PEEP and prone positioning on these variables is unknown. OBJECTIVES: To determine the effects of high PEEP and prone positioning on lung recruitment, cyclic recruitment/derecruitment, and tidal hyperinflation and how these effects are influenced by lung recruitability. METHODS: Mechanically ventilated patients (Vt 6 ml/kg ideal body weight) underwent whole-lung computed tomography (CT) during breath-holding sessions at airway pressures of 5, 15, and 45 cm H2O and Cine-CTs on a fixed thoracic transverse slice at PEEP 5 and 15 cm H2O. CT images were repeated in supine and prone positioning. A recruitment maneuver at 45 cm H2O was performed before each PEEP change. Lung recruitability was defined as the difference in percentage of nonaerated tissue between 5 and 45 cm H2O. Cyclic recruitment/de-recruitment and tidal hyperinflation were determined as tidal changes in percentage of nonaerated and hyperinflated tissue, respectively. MEASUREMENTS AND MAIN RESULTS: Twenty-four patients with ARDS were included. Increasing PEEP from 5 to 15 cm H2O decreased nonaerated tissue (501 ± 201 to 322 ± 132 grams; P < 0.001) and increased tidal-hyperinflation (0.41 ± 0.26 to 0.57 ± 0.30%; P = 0.004) in supine. Prone positioning further decreased nonaerated tissue (322 ± 132 to 290 ± 141 grams; P = 0.028) and reduced tidal hyperinflation observed at PEEP 15 in supine patients (0.57 ± 0.30 to 0.41 ± 0.22%). Cyclic recruitment/de-recruitment only decreased when high PEEP and prone positioning were applied together (4.1 ± 1.9 to 2.9 ± 0.9%; P = 0.003), particularly in patients with high lung recruitability. CONCLUSIONS: Prone positioning enhances lung recruitment and decreases alveolar instability and hyperinflation observed at high PEEP in patients with ARDS.

[Aluminium in the lower respiratory tract of people living in México City]. / Aluminio en el Tracto Respiratorio Bajo de Residentes de la Ciudad de México.

OBJECTIVE: Investigating the presence of aluminium (Al) and respiratory pathologies in the lower respiratory tract of people who had lived in Mexico City for a minimum of two years. METHODS: 250 respiratory tissue samples were obtained from pulmonary lobes, lymph nodes, bronchial and hilum regions during 36 individuals' autopsies. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used for quantifying Al; the samples has been previously dried, ground and digested. RESULTS: 13 different pathologies were identified but only three of them (pulmonary emphysema, bronchitis and anthracosis) were correlated with the presence of Al, an element being distributed in very variable concentrations (range: 2.7 to 836.1 micrograms of Al per gram of dry tissue (ì g Al/g ts)). The amount of Al found in lobes, bronchial and hilum regions was much smaller than that found in lymph nodes; such difference was statistically significant. Multivariate analysis by conglomerates revealed that the sample consisted of three classes of individuals, grouped according to the amount and distribution of Al in the lower respiratory tract, age, time spent living in Mexico City and the presence of pathologies. CONCLUSIONS: The Al found in the lower respiratory tract of residents of Mexico City would thus seem to have come from the air. The amount of Al and its distribution pattern depended on the time and place of residence and can lead to respiratory illness.

Aluminio en el tracto respiratorio bajo de residentes de la Ciudad de México / Aluminium in the lower respiratory tract of people living in México City

Objetivo Se investigó la presencia de aluminio (Al) y de patologías respiratorias en el tracto respiratorio bajo de personas que habían residido en Ciudad de México por un tiempo mínimo de dos años. Métodos Se obtuvo 250 muestras de tejido respiratorio (lóbulos pulmonares, nódulo linfático peribronquial, bronquios e hilio), durante la autopsia médico legal de 36 individuos. Para la cuantificación de Al se utilizó plasma de inducción acoplado (ICP -OES) a la espectrofotometría de absorción atómica previo a lo cual las muestras fueron sometidas a un proceso de secado, trituración y digestión. Resultados Se identificaron 13 diferentes patologías, solo tres de ellas: enfisema pulmonar, bronquitis y antracosis, se correlacionan con la presencia de Al, elemento distribuido en concentraciones muy variables (rango:2,7 a 836,1 microgramos de Al por gramo de tejido seco (ì g Al/g ts). En lóbulos, bronquios e hilio la cantidad de Al encontrada fue mucho menor que la encontrada en nódulos peribronquiales, siendo la diferencia estadísticamente significativa. El análisis multivariado por conglomerados mostró que la muestra estaba conformada por tres clases de individuos, agrupados de acuerdo a la cantidad y distribución del Al en el tracto respiratorio bajo, a la edad, tiempo de residencia en la ciudad de México y presencia de patologías. Conclusión Se postula que el Al encontrado en el tracto respiratorio bajo de residentes de ciudad de México proviene del aire; la cantidad y el patrón de distribución dependen del tiempo y del lugar de residencia y al depositarse puede provocar enfermedades respiratorias.

Objective Investigating the presence of aluminium (Al) and respiratory pathologies in the lower respiratory tract of people who had lived in Mexico City for a minimum of two years. Methods 250 respiratory tissue samples were obtained from pulmonary lobes, lymph nodes, bronchial and hilum regions during 36 individuals' autopsies. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used for quantifying Al; the samples has been previously dried, ground and digested. Results 13 different pathologies were identified but only three of them (pulmonary emphysema, bronchitis and anthracosis) were correlated with the presence of Al, an element being distributed in very variable concentrations (range: 2,7 to 836,1 micrograms of Al per gram of dry tissue (ì g Al/g ts)). The amount of Al found in lobes, bronchial and hilum regions was much smaller than that found in lymph nodes; such difference was statistically significant. Multivariate analysis by conglomerates revealed that the sample consisted of three classes of individuals, grouped according to the amount and distribution of Al in the lower respiratory tract, age, time spent living in Mexico City and the presence of pathologies. Conclusions The Al found in the lower respiratory tract of residents of Mexico City would thus seem to have come from the air. The amount of Al and its distribution pattern depended on the time and place of residence and can lead to respiratory illness.