Resumen El síndrome de la bolsa de orina púrpura es una condición clínica de prevalencia desconocida en Colombia debido al escaso reporte de casos a nivel nacional. Esta entidad se presenta exclusivamente en pacientes portadores de sonda vesical con factores de riesgo asociados como enfermedad renal crónica, patologías neurológicas, residentes de hogares geriátricos, sexo femenino, entre otros. La coloración púrpura de la orina se da en un ambiente urinario alcalino propiciado por bacterias específicas, en donde se genera una reacción de oxidación del indoxil sulfato en índigo e indirrubina por acción de las enzimas fosfatasas/sulfatasas de estos microorganismos, dichos pigmentos se mezclan generando la coloración púrpura en la bolsa urinaria. Se reporta el caso de un paciente masculino de 75 años con un cuadro clásico de síndrome de la bolsa urinaria púrpura, con el propósito de ampliar el conocimiento en la literatura nacional vigente. Adicionalmente, con esta publicación se busca que los profesionales de la salud comprendan los mecanismos fisiopatológicos por los cuales se produce esta entidad para saber abordarla apropiadamente.

Abstract Purple urine bag syndrome is a rare clinical condition, of unknown prevalence, with few reports published in our country that presents exclusively in catheterized patients with multiple risk factors, such as chronic kidney disease, neurological pathologies, residents of nursing homes and affects more females than males. The purple discoloration of urine is generated by indoxyl-sulfate degradation to indigo and indirubin lead by phosphatases/sulphatases enzymes produced by specific bacteria, associated to an alkaline urine environment, those two pigments combine which turns to purple discoloration appreciated in the urinary bag and catheter. The present case report is about a 75-year-old male, which appears with a classic clinical presentation. This case report has the objective, for health care workers, to remember the importance of basic care of urinary catheters, understand the underlying physiopathology and in consequence improve patient care.

Abstract Potato yield is strongly dependent on nitrogen fertilization, thus understanding the crop ecophysiological response is essential to improve the management of the agro-ecological resources. However, studies on biomass and nitrogen partitioning under different nitrogen fertilization are still limited for potato cultivars of the tropical Andes of Venezuela. The aim of this study was to determine the effects of nitrogen fertilization on patterns of biomass and nitrogen partitioning during the main phenologycal stages of cultivar Granola in Mérida, State of Mérida, Venezuela. The fertilization treatments (partitioning) were: Control treatment (0-N), 133 kg N ha-1 (133-N), and 400 kg N ha-1 (400-N). Experimental plots were set up in a randomized blocks design with three replications. Biomass and nitrogen levels were measured for each organ of the plant during the main phenological stages of the crop. The tuber yield performance and the total biomass were strongly influenced by nitrogen availability and the assimilatory biomass. Total biomass production as well as biomass and nitrogen partitioning to each plant organ followed the sequence fertilization rates: 400-N > 133-N > 0-N. However, biomass and nitrogen partitioning to the roots and stolons was higher in the treatment with limited nitrogen levels. Proportional changes among aboveground and belowground biomass are adaptive responses to nitrogen deficit; which in turn, are determining factors in crop production.

Resumen El rendimiento de la papa se ve fuertemente afectada por la fertilización nitrogenada, por lo que comprender las respuestas ecofisiológicas del cultivo es esencial para mejorar el manejo de los recursos agroecológicos. Sin embargo, los estudios sobre el fraccionamiento de biomasa y nitrógeno bajo diferentes tratamientos de fertilización nitrogenada aún son limitados para los cultivares de los Andes tropicales de Venezuela. El objetivo de este estudio fue determinar los efectos de la nutrición de nitrógeno en el patrón de fraccionameinto de biomasa y nitrógeno durante el cultivo de papa en Mérida, Estado Mérida, Venezuela. Se establecieron parcelas experimentales, con un diseño de bloques al azar y con tres tratamientos de fertilización para el cultivar “Granola”: sin nitrógeno (0-N), 133 kg N ha-1 (133-N), 400 kg N ha-1 (400-N). En las principales etapas fenológicas del cultivo, se midieron los niveles de biomasa y nitrógeno para cada órgano. El rendimiento de los tubérculos y la biomasa total están fuertemente influenciados por la disponibilidad de nitrógeno y biomasa asimilatória. La producción total de biomasa, así como el fraccionamiento de biomasa y nitrógeno en cada órgano, mostraron la siguiente secuencia: 400-N> 133-N> 0-N. Sin embargo, la partición de biomasa y nitrógeno a las raíces y estolones fue mayor en el tratamiento con niveles limitados de nitrógeno. Los cambios proporcionales entre la biomasa aérea y subterránea son respuestas adaptativas a las condiciones de déficit de nitrógeno, que, a su vez, son factores determinantes en la producción del cultivo.

Phase transition and viscosity behavior of emulsified systems were studied after modifying their physicochemical formulation. Effects of concentration and nature of salts and n-alcohols, and water/oil relation on the rheological properties of emulsions were also studied. Pre-equilibrated systems were emulsified according to an agitation procedure, and the viscosity (cP) was measured at different shear rates ranging from 1 to 300 s-1. The phase behavior, as well as the emulsion type based on electrolytic conductivity, was observed. Several interpretations of the flow and viscosity curves of emulsions were made through the estimation of rheological parameters such as consistency index "k" and behavior index "n".

The phase behavior of an alcohol polyethoxylated surfactant with decane and dodecane oil phase varying the water proportion from 5 to 90% to determine compositions in which the formation of liquid crystals and microemulsions ocurred was investigated. Pseudoternary phase diagrams were built to represent the regions of liquid crystals, biphases and microemulsions. Polarized light optical microscopy was used for the analysis and characterization of the separate phases. The micrographs obtained showed characteristics of hexagonal and lamellar phases of liquid crystal, isotropic phases, microemulsions and vesicles. This study is important to propose hypothesis regarding the factors determining the formation and stability of phases composed by surfactant/oil/water systems.

The use of fatty acids (FAs) as amphiphiles is very important because they have a behaving similar to surfactants. The formulation for the preferential partition of these species was studied by varying the amount of salt at constant acid concentration. As the salt concentration increases, a Winsor I→III→II transition is observed for all the systems studied. Furthermore, the electrolyte concentration required to obtain the optimum formulation varies inversely with the chain length of the acid. The partition coefficient of the surfactant allows one to obtain thermodynamic information on the acid transfer process between the phases of the system.

El objetivo del presente trabajo fue medir los cambios séricos en las enzimas ALT, AST, FA, CK-TOTAL Y LDH inducidos por veneno de Crotalus durissus cumanensis en ratones balb/c que fueron inoculados con veneno crudo a una dosis de 0,75 mg proteínas/kg vía intraperitoneal, y los controles con solución fisiológica. Las muestras fueron obtenidas a diferentes intervalos de tiempo post inyección (1; 3; 6; 12 y 24 h) y se determinó la actividad de las enzimas: Alanina Aminotransferasa (ALT), Aspartato Aminotransferasa (AST), Fosfatasa Alcalina (FA), Creatina cinasa-total (CK-total) y Lactato Deshidrogenasa (LDH). Se observó diferencia significativa (P<0,05) en las ALT a partir de 1h post inyección hasta la 6h y (P<0,01) desde la 12h a las 24h con un valor máximo de 181 U/L a las 24h. La AST presentó un aumento significativo entre las 1h y las 24h, y entre las 3h y 12h alcanzando un máximo de 1066,8 U/L a las 6h, mientras que en la FA esta diferencia se observó desde la 12h a las 24h con un máximo de 201,6 U/L a las 12h. La CK- Total comienza a incrementarse a partir de la 1h post inyección, pero este incremento es significativo (P<0,01) desde las 6h hasta las 24h. La enzima LDH no presenta diferencias significativas en la 1h post inyección, sin embargo, experimenta un aumento significativo (P<0,01) desde la 3h y se mantiene a las 24h con un valor máximo 1390,2 U/L. El incremento de ALT, AST, y FA sugiere daño hepático. Los resultados obtenidos en la determinación de la CK-total y LDH pudieran indicar un daño de la musculatura del tejido cardíaco y/o esquelético en las primeras 24h de exposición al veneno de Crotalus durissus cumanensis.

The objective of the present work was to measure the serum changes in the enzymes ALT, AST, AF, TOTAL-CK and LDH induced by the venom of Crotalus durissus cumanensis in Balb/C mice which been inoculated with crude venom in a doses of 0.75 mg/kg by intraperitoneal way, and the control with physiological solution. The samples were obtained at different intervals post-injection (1, 3, 6, 12 and 24 h) and was determinated the activity of the enzymes: Alanine Aminotransferase (ALT), Aspatate Aminotransferase (AST) and Alkaline Phosphatase (AF); Total Creatin Kinase (TCK) and Lactate Deshidrogenase (LDH). There was significant difference (P<0.05) in the ALT since the 1h post-injection to the 6h and high significant (P<0.01) since the 12h to the 24h with a maximum value of 181 U/L at the 24h, the AST show a significant rise between the 1h and the 24h, higher significant between 3h and 12h reaching a maximum of 1066,8 U/L at the 6h, while the AF this difference was observed since the 12h to the 24h; with a maximum of 201,6 U/L. The Total-CK begin to rise since the 1h post-injection, but this increase is higher significant (P<0.01) since the 6h to the 24h. The enzyme LDH didn’t show significant difference at the 1h post-injection, however it show a rise higher significant (P<0.01) since the 3h a keep at the 24h with a maximum value 1390.2 U/L. The rise of ALT, AST and AF in this study suggests hepatic injury. The results obtained in the determination of the TOTAL-CK and LDH may indicated an injury at the cardiac and/or skeletal muscle at the first 24 hours after the exposure to the Crotalus durissus cumanensis venom.

Los crudos pesados presentan problemas en la deshidratación debido a la presencia de emulsiones estables, con un contenido de agua mayor a 1%. En este trabajo se propone la aplicación del calentamiento con radiación microondas (CMW) para favorecer la separación del agua emulsionada en un crudo pesado, como método alternativo al calentamiento convencional estándar (CCE). Los resultados obtenidos mostraron que ambos métodos son efectivos para la deshidratación del crudo ya que el contenido de agua fue menor de 1,0%, no obstante, la metodología aplicada en el método termoquímico empleando CMW requirió de menor tiempo de análisis comparado con el CCE, ventaja importante en la disminución de costos y en los análisis de campo en la industria petrolera.

The heavy crude oil presents problems in the dehydration due to the presence stable emulsions, with water content more than to 1.0%. In this work is proposed the application of microwaves heating (MWH) to favor the separation of emulsioned water in this crude oil, as alternative method to the standard conventional heating (SCH). The obtained results showed that both methods are effective for the crude oil dehydration since the content of water was smaller than 1.0%, nevertheless, the applied methodology in the thermal chemical methods using MWH required lower analysis time compared with the SCH, important advantage for the decrease of production costs and in the field analyses in the oil industry.

Las emulsiones de crudo en agua se han utilizado para producir y transportar hidrocarburos pesados. En estudios anteriores se determinó que las emulsiones de crudo en agua preparadas con mezclas de surfactantes no-iónicos y aniónicos son más estables y menos viscosas que las emulsiones preparadas con un único surfactante, y que adicionando aminas de cadena corta se logra incrementar la estabilidad de dichas emulsiones. En este artículo se discute el efecto de aminas alifáticas de cadena corta en la estabilidad y las propiedades reológicas de emulsiones de crudo pesado en agua, preparadas a una relación crudo/agua 70/30. Se utilizaron surfactantes no-iónicos polietoxilados, tanto individualmente como mezclados con un surfactante aniónico del tipo aril benceno sulfonato. Se emplearon como co-surfactantes aminas alifáticas de 2, 4 y 6 átomos de carbono, tanto de cadena lineal como ramificada. Los resultados mostraron que las aminas primarias de cadena lineal producen emulsiones más estables y con mayor viscosidad que las emulsiones preparadas con aminas secundarias o terciarias de igual número de átomos de carbono. Se concluyó que las aminas alifáticas cortas son excelentes co-surfactantes, ya que estabilizan las emulsiones formadas en el sistema surfactante-agua-crudo.

The crude oil in water emulsions have been used to produce and to transport heavy hydrocarbons. More stability and less viscosity than the emulsions prepared with an only surfactant was obtained for the crude oil in water emulsions prepared with non-ionic and anionic surfactant mixtures, in previous studies. The stability of these emulsions could be increased, adding short chain amines. In this work, the effect of aliphatic short chain amines in the stability and the rheological properties of heavy crude oil in water emulsions, prepared at crude oil/water relationship of 70/30, is discussed. Polyethoxylated non-ionic surfactants were used, individually or in a mixture with an anionic surfactant of aryl benzene sulfonate type. Aliphatic short chain amines of 2, 4 and 6 atoms of carbon were used as co-surfactants, so much of lineal chain and ramified chain. The results showed that the primary amines of lineal chain produce more stable emulsions and with more viscosity that the emulsions prepared with secondary or tertiary amines of the same number of atoms of carbon. It was concluded that aliphatic short chain amines are excellent co-surfactants, because they stabilize micelles formed inside the system surfactant-water-crude oil.

En el presente trabajo se evaluaron formulaciones para emulsionar crudo pesado en agua, a una relación crudo/agua 70/30. Se utilizaron surfactantes no-iónicos y aniónicos, mientras que aminas de cadena corta se emplearon como co-surfactantes. Se evaluaron la estabilidad, la viscosidad, la conductividad, el tamaño promedio de gota y la distribución de tamaño promedio de gota. Se obtuvieron emulsiones estables para sistemas simples y múltiples, cuyas viscosidades son considerablemente menores a la viscosidad original del crudo, todas de fase externa agua y con una amplia zona de inversión. El tamaño mínimo promedio de gota obtenido fue de 23 mm, con distribuciones polidispersas, tanto unimodales como bimodales. Se concluyó que las mezclas de surfactantes no-iónicos y aniónicos originan una sinergia positiva incrementando la estabilidad de las emulsiones de crudo en agua, y que las aminas de cadena corta son excelentes co-surfactantes, ya que estabilizan las micelas formadas dentro del sistema surfactante-agua-crudo

In the present work, formulations to emulsify heavy crude oil in water, at crude oil/water relationship of 70/30, were evaluated. Non-ionic and anionic surfactants were used with amines of short chain as co-surfactants. Stability, viscosity, conductivity, drop size and size distribution, were evaluated. Stable emulsions were obtained with simple and multiple systems which smaller viscosities than the original crude oil, all them with external phases of water and “extended inversion zone”. The minimum drop size obtained was of 23 µm, with polydisperses distributions, unimodals and bimodals. It was concluded that non-ionic and anionic surfactants mixtures originate a positive synergy, increasing the stability of the crude oil emulsions, and as well as that short chain amines are excellent co-surfactants, because they stabilize micelles formed inside the surfactant-water-crude oil system

Diferentes fracciones de un crudo pesado soportado en alúmina neutra, ácida y básica, se aislaron aplicando extracción Soxhlet utilizando como solventes acetonitrilo, metanol, n-heptano, tolueno y tetrahidrofurano. Los surfactantes naturales (SN) de las fracciones con alúmina neutra se extrajeron usando mezclas de aceite y agua a diferentes pH. Las fracciones y SN aislados se caracterizaron utilizando espectrometría UV-Visible, infrarrojo, tensiometría y cromatografía de permeación de geles (GPC). Los resultados indicaron que la mayor cantidad de SN se obtuvo a pH 8 con una proporción agua/aceite 30:70. Utilizando tetrahidrofurano se logró extraer los SN retenidos en las alúminas ácida y básica con una recuperación entre 5 y 7%, las cuales fueron mayores a las obtenidas por la extracción líquido-líquido (entre 3 y 4%).

Different fractions of a heavy crude oil supported in neutral, acid and basic alumina, were isolated by Soxhlet extraction using solvent such as acetonitrile, methanol, n-heptane, toluene and tetrahydrofuran. The natural surfactants (SN) of the neutral fractions were extracted using mixtures of oil and water at different pH. The extracted fractions and isolated SN were characterized using UV-VIS and IR spectroscopy, tensiometry and gel permeation chromatography. The results indicate that the largest SN amount is obtained at pH 8 with a water/oil 30:70 ratio. Using tetrahydrofuran it was possible to extract the SN retained in the acid and basic alumina with a recovery between 5 and 7%, i.e. values similar to those obtained by liquid-liquid extraction (between 3 and 4%).