609 research outputs found
Bilateral adrenalectomy for asynchronous metastases of a malignant melanoma
Indexación: Web of Science; Scielo.Clinical case: We report a 70 years old male with a history of an ear lobe melanoma with was excised seven years ago, who had a bronchial relapse and required a right pneumonectomy. During a follow up abdominal CAT scan, a 9 cm tumor in the left adrenal gland was detected. The patient was operated, performing a left adrenalectomy and nephrectomy. The pathologic study confirmed the presence of a fusocellular melanoma. One year later, a right adrenal mass was detected and excised. The pathological study of the piece again confirmed a metastasis of a malignant melanoma. The patient died due to progression of the disease, 10 years after the adrenalectomy.
Key words: Adrenal metastases, laparoscopic adrenalectomy, melanoma.Objetivo: Presentar un caso de metástasis suprarrenal bilateral asincrónica de Melanoma cutáneo tratado con adrenalectomía laparoscópica bilateral. Caso clínico: Paciente de 70 años con antecedente de melanoma del pabellón auricular extirpado 7 años antes de su consulta urológica. Posteriormente, presenta una recidiva bronquial tratada con quimioterapia, radioterapia y neumonectomía derecha. En sus exámenes de seguimiento una Tomografía computada muestra el hallazgo incidental de una lesión tumoral de 9 cm en la glándula suprarrenal izquierda. Se realizó nefrectomía y adrenalectomía izquierda laparoscópica en bloque sin incidencias. El análisis histopatológico confirmó el hallazgo de una metástasis de melanoma fuso-celular. Un año después el paciente presenta un nuevo hallazgo incidental de un tumor de 3 cm en la glándula suprarrenal derecha, la cual fue tratada con adrenalectomía laparoscópica, y cuyo análisis histopatológico demostró metástasis de melanoma maligno. El paciente fallece por progresión de su enfermedad 10 años después de su cirugía suprarrenal. Conclusiones: En los pacientes con metástasis suprarrenal de melanoma, la adrenalectomía incrementa la supervivencia cáncer especifica en relación a los pacientes tratados sin cirugía. El abordaje laparoscópico constituye una alternativa terapéutica con menor morbilidad que la cirugía abierta en cirujanos con experiencia laparoscópica.
Palabras clave: Metástasis suprarrenal, adrenalectomía laparoscópica, melanoma.http://ref.scielo.org/mymgk
Stellar populations in the Carina region : The Galactic plane at l = 291°
Context. Previous studies of the Carina region have revealed its complexity and richness as well as a significant number of early-type stars. However, in many cases, these studies only concentrated on the central region (Trumpler 14/16) or were not homogeneous. This latter aspect, in particular, is crucial because very di erent ages and distances for key clusters have been claimed in recent years.
Aims. The aim of this work is to study in detail an area of the Galactic plane in Carina, eastward η Carina.We analyze the properties of di erent stellar populations and focus on a sample of open clusters and their population of young stellar objects and highly reddened early stars. We also studied the stellar mass distribution in these clusters and the possible scenario of their formation. Finally, we outline the Galactic spiral structure in this direction.
Methods. We obtained deep and homogeneous photometric data (UBVIKC) for six young open clusters: NGC 3752, Trumpler 18, NGC 3590, Hogg 10, 11, and 12, located in Carina at l ~ 291°, and their adjacent stellar fields, which we complemented with spectroscopic observations of a few selected targets. We also culled additional information from the literature, which includes stellar spectral classifications and near-infrared photometry from 2MASS.We finally developed a numerical code that allowed us to perform a homogeneous and systematic analysis of the data. Our results provide more reliable estimates of distances, color excesses, masses, and ages of the stellar populations in this direction.
Results. We estimate the basic parameters of the studied clusters and find that they identify two overdensities of young stellar populations located at about 1.8 kpc and 2.8 kpc, with EB-V ~ 0.1-0.6. We find evidence of pre-main-sequence populations inside them, with an apparent coeval stellar formation in the most conspicuous clusters. We also discuss apparent age and distance gradients in the direction NW-SE. We study the mass distributions of the covered clusters and several others in the region (which we took form the literature). They consistently show a canonical IMF slope (the Salpeter one). We discover and characterise an abnormally reddened massive stellar population, scattered between 6.6 and 11 kpc. Spectroscopic observations of ten stars of this latter population show that all selected targets were massive OB stars. Their location is consistent with the position of the Carina-Sagittarius spiral arm.Instituto de Astrofísica de La PlataFacultad de Ciencias Astronómicas y Geofísica
Description of analyzing power and (p,n) reaction by a global dispersive coupled-channel optical model potential
A global dispersive coupled-channel optical model potential is used to analyze the proton
elastic/inelastic analyzing power data and (p,n) data in order to investigate the prediction power of this potential. The numerical calculations show good agreement with available experimental data for proton elastic data and overall agreement for proton inelastic data. The results also showed that present global potential is approximately Lane-consistent, and can predict well the (p,n) cross sections
Dispersive optical model description of nucleon scattering on Pb and Bi isotopes
A recently derived dispersive optical model potential (DOMP) for 208Pb is extended to consider the nonlocality
in the real potential and the shell gap in the definition of the nuclear imaginary potentials near the Fermi energy.
The modified DOMP improves the simultaneous description of nucleon scattering on 208Pb and of the 208Pb
particle-hole bound states. This potential is shown to give a very good description of nucleon scattering data on
near-magic targets 206,207Pb and 209Bi.Science Challenge Projects TZ2018001 y TZ201800
Hydropower plant models: water supply system, turbine and governor : Model validation: on site tests and grid fault simulation
Several tests were conducted at Futaleufú hydropower plant to improve plant related models because studies carried out in the past did not predict the power plant behaviour during grid faults. New models were used to reproduce Futaleufú power plant behaviour during a grid fault happened on December 14, 2006.Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos (IITREE
Hydropower plant models: water supply system, turbine and governor : Model validation: on site tests and grid fault simulation
Several tests were conducted at Futaleufú hydropower plant to improve plant related models because studies carried out in the past did not predict the power plant behaviour during grid faults. New models were used to reproduce Futaleufú power plant behaviour during a grid fault happened on December 14, 2006.Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos (IITREE
Interaction between AVR reactive power control and high power AC-DC converter control as possible cause of instability
Two oscillatory episodes took place in the Argentinean power system at 22:20 and 22:50, June 7th, 2008. The first one started when a 40 MVAr capacitors bank was disconnected and the second one started when a 500 kV line was disconnected. Both oscillatory episodes produced great variation of active and reactive power in several 330 kV and 500 kV power system nodes. At first sight, these oscillations seemed inter-area electromechanical oscillations, but carried out studies suggest that this oscillatory behavior could be a consequence of interaction between Reactive Power Control of generators and the ac-dc Converter Control of high power loads.Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos (IITREE
Caracterización de la carga a través de la determinación del coeficiente de sensibilidad con la frecuencia y de las desviaciones estándar de la misma en el Sistema Argentino Interconectado
Se midieron y registraron una gran cantidad de transitorios de la frecuencia del sistema provocados por eventos conocidos como pérdida de generadores y carga y descarga de bombas de la estación generadora de bombeo de Río Grande ubicada en la provincia de Córdoba, Argentina. Además se registraron variaciones rápidas de la potencia de carga en distintos nodos de la red.
Con estas mediciones se procedió a estimar el coeficiente de sensibilidad de la carga a la frecuencia y a evaluar las desviaciones standard de las variaciones no previstas de la carga.
Para la estimación del coeficiente de sensibilidad de la carga a la frecuencial se simuló, a partir de los datos de operación en el momento del evento, el transitorio de frecuencia. Se determinó el valor del coeficiente como aquel que mejor ajuste la curva del transitorio real de frecuencia medido.
Para la caracterización estadística, a través de la desviación estándar de las variaciones de la carga, se utilizaron los registros rápidos de la potencia de carga y planillas de operación diarias. Se obtuvieron resultados primarios de desviaciones estándar correspondientes a diferentes duraciones de las variaciones y luego se los combinaron para obtener las desviaciones que deben considerarse para la determinación de cada tipo de reserva. Se analizaron diferentes casos según sea la estrategia de utilización de cada reserva.Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos (IITREE
Caracterización de la carga a través de la determinación del coeficiente de sensibilidad con la frecuencia y de las desviaciones estándar de la misma en el Sistema Argentino Interconectado
Se midieron y registraron una gran cantidad de transitorios de la frecuencia del sistema provocados por eventos conocidos como pérdida de generadores y carga y descarga de bombas de la estación generadora de bombeo de Río Grande ubicada en la provincia de Córdoba, Argentina. Además se registraron variaciones rápidas de la potencia de carga en distintos nodos de la red.
Con estas mediciones se procedió a estimar el coeficiente de sensibilidad de la carga a la frecuencia y a evaluar las desviaciones standard de las variaciones no previstas de la carga.
Para la estimación del coeficiente de sensibilidad de la carga a la frecuencial se simuló, a partir de los datos de operación en el momento del evento, el transitorio de frecuencia. Se determinó el valor del coeficiente como aquel que mejor ajuste la curva del transitorio real de frecuencia medido.
Para la caracterización estadística, a través de la desviación estándar de las variaciones de la carga, se utilizaron los registros rápidos de la potencia de carga y planillas de operación diarias. Se obtuvieron resultados primarios de desviaciones estándar correspondientes a diferentes duraciones de las variaciones y luego se los combinaron para obtener las desviaciones que deben considerarse para la determinación de cada tipo de reserva. Se analizaron diferentes casos según sea la estrategia de utilización de cada reserva.Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos (IITREE
Stellar populations in the Carina region : The Galactic plane at l = 291°
Context. Previous studies of the Carina region have revealed its complexity and richness as well as a significant number of early-type stars. However, in many cases, these studies only concentrated on the central region (Trumpler 14/16) or were not homogeneous. This latter aspect, in particular, is crucial because very di erent ages and distances for key clusters have been claimed in recent years.
Aims. The aim of this work is to study in detail an area of the Galactic plane in Carina, eastward η Carina.We analyze the properties of di erent stellar populations and focus on a sample of open clusters and their population of young stellar objects and highly reddened early stars. We also studied the stellar mass distribution in these clusters and the possible scenario of their formation. Finally, we outline the Galactic spiral structure in this direction.
Methods. We obtained deep and homogeneous photometric data (UBVIKC) for six young open clusters: NGC 3752, Trumpler 18, NGC 3590, Hogg 10, 11, and 12, located in Carina at l ~ 291°, and their adjacent stellar fields, which we complemented with spectroscopic observations of a few selected targets. We also culled additional information from the literature, which includes stellar spectral classifications and near-infrared photometry from 2MASS.We finally developed a numerical code that allowed us to perform a homogeneous and systematic analysis of the data. Our results provide more reliable estimates of distances, color excesses, masses, and ages of the stellar populations in this direction.
Results. We estimate the basic parameters of the studied clusters and find that they identify two overdensities of young stellar populations located at about 1.8 kpc and 2.8 kpc, with EB-V ~ 0.1-0.6. We find evidence of pre-main-sequence populations inside them, with an apparent coeval stellar formation in the most conspicuous clusters. We also discuss apparent age and distance gradients in the direction NW-SE. We study the mass distributions of the covered clusters and several others in the region (which we took form the literature). They consistently show a canonical IMF slope (the Salpeter one). We discover and characterise an abnormally reddened massive stellar population, scattered between 6.6 and 11 kpc. Spectroscopic observations of ten stars of this latter population show that all selected targets were massive OB stars. Their location is consistent with the position of the Carina-Sagittarius spiral arm.Instituto de Astrofísica de La PlataFacultad de Ciencias Astronómicas y Geofísica
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