Development and validation of a methodology for quantifying parts-per-billion levels of arsine and phosphine in nitrogen, hydrogen and liquefied petroleum gas using a variable pressure sampler coupled to gas chromatography-mass spectrometry.

The reliable determination of arsine (AsH3) and phosphine (PH3) in hydrogen (H2), nitrogen (N2) and liquefied petroleum gas (LPG) is of great importance because of its drastic effects on the efficiency of catalysts, as well as the strict regulations associated with health, safety and environmental issues. It is challenging for an analyst to determine the parts per billion of AsH3 and PH3 in H2, N2, and LPG at low and high pressures without collection procedures using adsorption, desorption, and dissolution techniques. To overcome this analytical need an analytical methodology was developed, employing a variable pressure sampler (VPS) coupled to a gas chromatograph (GC) with mass spectrometry (MS) for the identification and quantification of traces of AsH3 and PH3. The instrumentation, tubing and accessories of the VPS were made of passivated steel to avoid losses from absorption of AsH3 and PH3 in the steel which would generate significant analytical problems. The VPS had a homogeneous heating block that prevented analyte losses from condensation. With the VPS, 24 AsH3 and PH3 standards were prepared between 0.005 and 0.1 mg kg-1 in balance of H2, N2 and LPG. The separation and quantification of the analytes was achieved with an improved GC with 4 valves and 5 columns in series that guaranteed the elimination of impurities. The proposed method was optimized in VPS and GC-MS and then validated showing highly accaptable linearity (r2 > 0.9999), detection limits (<0.0009 mg kg-1), limits of quantification (<0.003 mg kg-1), intra-day and inter-day precision and accuracy (<1.14% and ≤3.0% respectively), recovery for the standard addition (86-109%), P values> 0.05 for the test Student's t paired who evaluated the effect of the matrix on pressure and concentration. The speed of analysis was high (<5.2 min). The method was applied to real samples, showing values between 0.005 and 0.1 mg kg-1 and an effect on the efficiency of the Ziegler Natta catalyst between 5 and 56%.

Quantification and elimination of substituted synthetic phenols and volatile organic compounds in the wastewater treatment plant during the production of industrial scale polypropylene.

Substituted synthetic phenols and VOC as industrial waste in water and gases from a polypropylene (PP) production plant were the focus of this research. The scope of the study included two levels of the process which were: extrusion and desorber. A total of 264 samples were taken of the liquid and gas affluent and effluent. Waste water and residual gases were collected during the processing of 6 grades of PP with melt flow index of 25, 20, 15, 10, 2 and 1. The monitoring programs were carried out over the course of a year and the samples were taken at different times in order to evaluate the stability and magnitude of a possible environmental impact of the process. Five phenols were identified in the wastewater and a total of 41 VOCs were found in the gas sample. The selection of these phenols was based principally on their high consumption given the need to improve the thermo-oxidative properties of the PP. For the study of the VOC, a new methodology was developed permitting simultaneous analysis by GC-MS/PDHID/FID combining 7 valves, 8 columns and 3 detectors. In the past the wastewaters were treated with solid phase extraction cartridges and the substituted phenols were analyzed by HPLC with DAD. In the VOCs 7 alkanes, 8 alkenes, 2 alkynes, 7 alcohols, 4 ketones, 2 carboxylic acids, 4 permanent gases, 4 sulfides and 3 thiols were detected. The 5 phenols identified were Irganox 1076, DTF, Etanox 330, Irganox 1010 and Cyanox 1790, and the highest concentrations of each one of these were identified in wastewater from the cutting of pellets with values of 380, 366, 396, 331 y 330 ppm respectively. The wastewater from the desorber showed the highest values for Irganox 1076 and DTF with maximum levels of 250 and 213 ppm respectively. These maximum values were obtained after processing the PP with a melt flow index of 25. The grades with fluidity of 1 and 2 generated the least migration of these phenols to the wastewater. The two industrial wastewater samples were transported to the wastewater treatment plant where the Irganox 1076 and the DTF were completely eliminated in the treatment process. The concentrations of Irganox 1010, Cyanox 1790 and Ethanox 330 were reduced over 90%.

Nuevos marcadores mitocondriales mejoran la filogenia de la tortuga carey Eretmochelys imbricata (Testudines: Cheloniidae) / New mitochondrial markers improve the phylogeny of the hawksbill turtle Eretmochelys imbricata (Testudines: Cheloniidae)

Las tortugas marinas (Cheloniidae) son un grupo de siete especies originadas en el cretaceo. Analisis de secuencias parciales de DNA mitocondrial han revelado inconsistencias filogeneticas dentro de este grupo de quelonios. Sin embargo, estos marcadores mitocondriales han permitido entender y dilucidar la composicion de las poblaciones en areas de forrajeo, habitos reproductivos, inferencias de patrones de migracion y tambien definir las unidades de manejo en el mundo, con el fin de proponer planes de manejo y conservacion. El objetivo de este estudio fue evaluar la posicion de la tortuga carey E. imbricata dentro de la familia Cheloniidae y la filogenia de las tortugas marinas utilizando genes mitocondriales codificantes de proteinas, genes ribosomicos y el genoma mitocondrial completo de la tortuga carey anidante del Caribe colombiano, al compararlo con las otras seis especies de tortugas marinas disponibles en GenBank. Se utilizaron cuatro metodos de inferencias filogeneticas: Neighbor-Joining (NJ), Maxima Verosimilitud (ML), Maxima Parsimonia (MP) e Inferencia Bayesiana (IB). Los arboles NJ, ML, MP e IB mostraron que ND2, COX1, 16S ARNr, ND5, 12S ARNr, ND4, COX3 y ND1 son los marcadores que presentan una mejor resolucion filogenetica con sustentos bootstrap entre 89,0% y 99,98%. Los genes ATP6, ATP8, COX2, ND3, ND4L y ND5 presentaron politomias y establecieron relaciones filogeneticas equivocadas. El analisis con el mitogenoma completo presento arboles altamente sustentados (bootstrap de 98,0%) en comparacion con el analisis con marcadores individuales. Los arboles obtenidos con el gen ND2 e IB resolvieron con buen sustento las relaciones evolutivas entre las especies comparadas, consolidandose la posicion de E. imbricata dentro de la tribu Carettini con probabilidad posterior de 0,98-1,0. Los marcadores ND2, ND5, ND4, COX3 y ND1 no han sido utilizados en trabajos previos y representan una nueva alternativa para explicar la filogenia en este grupo de reptiles marinos. En el presente caso utilizando mitogenomas completos se obtuvieron arboles robustos y altamente sustentados.

The sea turtles (Cheloniidae) are a group of seven species of cretaceous origin. Analyses of partial mitochondrial sequences have revealed phylogenetic inconsistences within this group. Nevertheless, these mitochondrial markers have allowed us to understand, explain and clarify population composition in areas of foraging, reproductive habits, inferences of migration patterns and, also, to define management units in the world, in order to trace conservation and monitoring plans. In this study, four methods were evaluated and compared for phylogenetic inference (Neighbor-Joining-NJ, Maximum Likelihood-ML, Maximum Parsimony-MP and Bayesian inference-BI) by using coding genes, ribosomal genes and full mitogenomes of the hawksbill, E. imbricata, and other six species of sea turtles obtained from GenBank. The sequences were analyzed independently and jointly to identify the method and marker that better explain the phylogenetic relationships among this group of reptiles. The NJ, ML, MP and BI trees showed that ND2, COX1, 16S rRNA, ND5, 12S rRNA, ND4 and COX3 are the markers that give phylogenetic trees with better resolution and support, with bootstrap values ranging from 89.0% to 99.98%. ATP6, ATP8, COX2, ND1, ND3, ND5 and ND4L genes presented polytomies. The analysis with full mitogenome often provides highly supported trees (bootstrap 98.0%) compared with single marker analysis. Trees obtained with the BI method and the ND2 gene is the one that better resolved the evolutionary relationships among the species, consolidating the position of E. imbricata within the Carettini tribe with a value of posterior probability of 0.98-1.0. The markers ND2, ND4, ND5 and COIII, not used in previous works, represent a new alternative to explain the phylogeny in this group of marine reptiles. In the present study, a complete mitogenome analysis produced robust and highly supported trees.

Detección molecular de potyvirus en hojas y minibulbillos de ajo, Allium sativum, asociados a un programa de producción de semilla limpia / Molecular detection of potyvirus in leaves and small bulbs of garlic, Allium sativum, associated a clean seed production program

El ajo (Allium sativum L) se reproduce vegetativamente utilizando bulbillos, condición que favorece la propagación de enfermedades, especialmente bacterias, hongos y virus que afectan la calidad y el rendimiento del cultivo. Por este motivo se implementó la identificación molecular por RT-PCR de los potyvirus LYSV y OYDV en el sistema de producción de semilla limpia de ajo en tres clones nacionales. En la fase de producción de semilla limpia mediante micropropagación, se estandarizó el establecimiento de meristemos de ajo. La presencia de potyvirus se analizó en 586 plántulas mediante ELISA y en 70 por RT-PCR. Para la RT-PCR se extrajo ARN a partir de microbulbillos y hojas de plántulas, obteniéndose 1.7 a 226 ng/microlitro de ARN y se sintetizó entre 35 a 50 ng de cADN. Los resultados obtenidos mostraron que el protocolo de desinfección produjo una viabilidad del 73.6%. El análisis ELISA presentó un saneamiento del 96.1% de las plántulas a potyvirus, mientras que con RT-PCR se identificó la presencia de LYSV en el 8.6% de las muestras evaluadas. El virus del enanismo amarrillo de la cebolla (OYDV) no fue detectado en ninguna de las muestras. Los resultados muestran que el cultivo in vitro de meristemos de ajo es una excelente alternativa para la producción de semilla, mostrando un 92% de eficiencia. Además, validan el diagnóstico eficiente del potyvirus LYSV en hojas y microbulbillos de ajo.

Garlic (Allium sativum L), reproduces vegetatively using bulbils, condition that favors the spread of diseases, especially bacteria, fungi and viruses, which affect the quality and crop yield. For this reason, the molecular identification by RT-PCR of potyvirus: LYSV and OYDV in the production system of clean seed garlic of three national clones were implemented. In the production phase of clean seed was establishing garlic meristems micropropagation. Potyvirus presence in 586 seedlings was analyzed by ELISA and for RT-PCR in 70. RNA was extracted from leaves and small bulbs, yielding 1.7 to 226 ng/μl, and with this RNA, between 35 to 50 ng of cDNA. The results showed that the disinfection protocol produced a 73.6% viability of plants. ELISA analysis showed 96% sanitation of seedling to potyvirus, whereas, Leek Yellow Strip Virus, LYSV was identified in 8.6% of samples used RT-PCR methodology. Onion yellow dwarf virus (OYDV) was not detected in any sample. The results show that the in vitro culture of meristem of garlic, is an excellent alternative for seed production, showing a 92% efficiency. Moreover, efficient diagnostics of LYSV potyvirus was validated in leaves and small bulbs of garlic.

[3 cases of diffuse lymphangioleiomyomatosis of the lung]. / A propósito de tres casos de linfangioleiomiomatosis pulmonar difusa.

Three new cases of diffuse pulmonary lymphangioleiomyomatosis are presented. Case number 1 is a female patient who presented repeated pneumotorax and dyspnea without evidence by CT scan and gynecological ultrasound of extrathoracic lesions. This patient did not respond to medroxiprogesterone and died 5 years after the initial diagnosis having suffered chronic, severe, global respiratory failure for 4 years. Case number 2 is a female patient who presented dyspnea, chyloptysis and chylothorax, with iliac, paraaortic and mediastinic lymphangioleiomyomas. The last time she was seen, she was still alive after 6 years without treatment. Case number 3 presented lymphangioleiomyomatosis associated to undifferentiated breast carcinoma. The evolution was apparently slow probably because it was diagnosed 14 years after menopause, and died due to a relapse of the neoplasia. All three patients had radiographic images and respiratory functional studies characteristic of this disease and diagnosis was confirmed by biopsy. The literature is reviewed.