Ru0·Ru n+/Al2O3 as a Versatile Catalyst in the Isomerization of Allyl Alcohol.

This study focuses on examining the isomerization of allyl alcohol using ruthenium (Ru) supported on alumina as a heterogeneous catalyst. The synthesized Ru/Al solids were characterized by various characterization techniques. The content of Ru was estimated by the energy dispersive x-ray technique. The x-ray diffraction (XRD) confirmed the presence of phases in the support and active species in the catalysts. The surface area of the support after Ru impregnation and the pore volume were determined by nitrogen physisorption. The analysis of programmed temperature (TPR and TPO) shows different redox sites which is confirmed by XPS. The catalytic results suggest a dependence on the amount of available metallic Ru, as well as the importance of the continuous regeneration of the metal using H2 to achieve a good conversion of the allyl alcohol. For comparison purposes, the commercial Ru on alumina 5% (CAS 908142) was used. The results show up to 68% alcohol conversion and 27% yield of the isomerization product using Ru(1,5.4h)/Al catalyst in comparison with 86% conversion and 39% yield of the isomerization product using CAS 908142. In contrast, our catalysts always presented higher TOF values (149-160) in comparison with CAS 908142 (101).

Trauma esplénico cerrado: predictores de la falla del manejo no operatorio / Blunt splenic trauma: predictors of failure of nonoperative management

Introducción. El manejo no operatorio del trauma esplénico cerrado es el método preferencial para la preservación esplénica; sin embargo, los criterios para decidir qué pacientes pueden ser manejados sin cirugía sigue siendo materia de debate. El objetivo de este estudio fue describir las características generales de estos pacientes, los resultados del manejo no operatorio y explorar los factores asociados a su falla. Métodos. Es un estudio descriptivo de los pacientes con diagnóstico de trauma esplénico cerrado, admitidos a un centro de atención de alta complejidad, durante el periodo comprendido entre enero de 2003 y marzo de 2009. Los pacientes se clasificaron en dos grupos: manejo operatorio y manejo no operatorio; en el último se analizaron los pacientes en los que falló dicho manejo. Un valor de p menor de 0,05 se consideró de significancia estadística. Resultados. Se incluyeron 82 pacientes. Después de la evaluación primaria o secundaria, el 25,6 % recibió manejo operatorio y, el 74,4 %, manejo no operatorio; el tratamiento no quirúrgico falló en el 22,9 %. Esta falla se asoció con un puntaje Injury Severity Score (ISS) mayor o igual a 20 (RR=6,4; IC95% 2,34-17,86), presencia de hemoperitoneo en la tomografía axial de ingreso (p=0,02) y el grado de lesión esplénica (p<0,001). Las complicaciones ocurrieron en el 31,7 % y las infecciones fueron la causa más frecuente en ambos grupos. La mortalidad global fue 7,3 % (3 pacientes en el grupo de manejo no operatorio y 3 en el de manejo operatorio), debida a las lesiones asociadas en la mayoría de los pacientes. Conclusiones. La mayoría de pacientes con trauma cerrado de bazo puede recibir manejo no operatorio, siendo este un método seguro y efectivo para la preservación esplénica, si se mantiene una vigilancia clínica continua, especialmente en casos de trauma grave.

Background: Nonoperative Management (NOM) of blunt splenic injuries is the preferred method of management for splenic preservation; however, the criteria for deciding what group of patients can be managed non-operatively remain controversial. The aim of this study was to describe the general features of this group of patients as well as to explore the results and factors related to failure of NOM. Methods: We described patients who were admitted to a first level trauma center with a diagnosis of blunt splenic injury between January 2003 and March 2009. The patients were classified in two groups: operative management and NOM; in the last group we analyzed the factors associated with failure. Results: A total of 82 patients were included in the study. Operative Management during the primary or secondary survey was performed on 25.6 % of patients, while 74.4% under went NOM. Of those who underwent NOM, 22.9% failed treatment. An Injury Severity Score (ISS) ≥20 (RR: 6.4 – CI 95%: 2.34-17.86), hemoperitoneum on the initial computed tomography (CT) scan (p=0.02), and splenic injury grade were factors associated with failed NOM (FNOM). The overall mortality rate was 7.3%; 14.3% for OM and 4.9% for NOM groups, respectively. Conclusions: The majority of blunt splenic trauma patients are candidates for NOM, as it is a safe and effective technique for splenic preservation if continuous medical surveillance is maintained.

Consenso médico de biopsia por aspiración con aguja fina de tiroides. reporte de citología tiroidea basado en el sistema de bethesda / Medical consensus of fine-needle aspiration biopsy of the thyroid. bethesda system for reporting thyroid cytopathology

En este artículo se presenta un consenso médico basado en el sistema de Bethesda del Instituto Nacionalde Cáncer (Estados Unidos) para el uso de la biopsia por aspiración con aguja fina en el manejo de nódulos tiroideos, realizado en conjunto con patólogos, radiólogos, endocrinólogos y otras especialidades médicas de Colombia, España, Chile, Venezuela, Estados Unidos y Panamá. En este trabajo se describen las indicaciones de la biopsia por aspiración con aguja fina de tiroides, requisitos previos, entrenamiento, acreditación, técnicas, terminología diagnóstica, pruebas complementarias y opciones de tratamiento. El objetivo del actual artículo es presentar ante la comunidad médica la clasificación de los reportes citológicos, el reporte de ecografía que propone usar el sistema de datos y el reporte de imágenes tiroideas (TIRADS, del inglés The Thyroid Imaging Reporting and Data System), el uso de la medición de tiroglobulina en biopsia por aspiración con aguja fina y técnicas de citología líquida;...

This article presents a medical consensus based on the Bethesda system of the National Cancer Institute (USA) for the use of fine needle aspiration biopsy in the management of thyroid nodules. This consensus was performed in conjunction with pathologists, radiologists, endocrinologists, and other medical specialties of Colombia, Spain, Chile, Venezuela, United States, and Panama. In this work was described the indications for fine needle aspiration biopsy of thyroid, prerequisites, training, accreditation, techniques, diagnostic terminology, additional tests and treatment options. The aim of this article is present to the medical community the classification of cytological report, ultrasound report using the data system, and the thyroid imaging reporting and data system (TIRADS); as well as, the use of thyroglobulin measurement in fine needle aspiration biopsy, and liquid-based cytology techniques...

Efecto del vanaiio en catalizadores derivados d materiales tipo hidrotalcita een deshidrogenación oxidativa de propnoo / Effect ofvanadiuum in catalysts derived fom hydrotalcite-like materials in oxidative dehidrogenation of propnee / Efeito dovanádioo em catalisadores derivaos de materiais tipo hidrotalciita na desidrogenação oxidativa de propano

Dos nuevos materiales tipo hidrotalcita, basados en NiCoCr y NiCoFe, se obtuvieron por el método hidrotérmico. Estos materiales se modificaron con especies de vanadio por intercambio iónico. Los sólidos se caracterizaron usando difracción de rayos X (DRX), análisis elemental (absorción atómica), y análisis termogravimétrico (ATG). Los sólidos con y sin intercambio se trataron térmicamente para obtener los respectivos óxidos mixtos, que posteriormente se evaluaron en la reacción de deshidrogenaciónoxidativa de propano (Dhop) a una velocidad espacial de 50 mL/min g y en un rango de temperatura comprendido entre 250 y 500 °C. Los estudios catalíticos mostraron un efecto positivo al incorporar el vanadio para el material NiCoCr, mientras que para el sistema NiCoFe modificado se observó una disminución en su actividad catalítica.

Two novel hydrotalcite-like materials have been synthesized by hydrothermal treatment. Using ionic exchange method, the materials have been modified with vanadium species. Characterization of the materials was carried out by X-Ray diffraction (XRD), chemical analyses (atomic absorption), and Thermogravimetric analyses (TGA). Modified and non-modified materials have been calcined in order to obtain respective mixed oxides, which were tested in oxidative dehydrogenation of propane (ODHP) at a space velocity of 50 mL/min g with a temperature range between 250-500 °C. The catalytic studies showed a positive effect by incorporating vanadium for NiCoCr system, while for the NiCoFe modified system a decrease in catalytic activity was shown.

Dois novos materiais tipo hidrotalcita baseados em NiCoCr e NiCoFe obtiveram-se pelo método hidrotérmico. Esses materiais foram modificados com espécies de vanádio por troca iô nica. Os materiais caracterizaram-se usando difração de raios X (DRX), análise elementar (absorçãoatômica) e análisetermogravimétrica (ATG). Os sólidos com e sem troca foram tratados termicamente para obter os respectivos óxidos mistos, que posteriormente se avaliaram na reação de desidrogenaçãooxidativa de propano (DHOP) a uma velocidade espacial de 50 mL/min g e em uma faixa de temperatura entre 250 a 500 °C. Os estudos catalíticos mostraram um efeito positivo ao incorporar o vanádio para o material NiCoCr, enquanto para o sistema NiCoFe modificado foi observada uma diminuiçãona sua atividade catalítica.

Total oxidation of toluene over calcined trimetallic hydrotalcites type catalysts.

Two trimetallic ZnCuAl and MnCuAl hydrotalcites have been successfully synthesized by a co-precipitation method. The manganese based material was identified as a new hydrotalcite phase. Both lamellar precursors were calcined at 450 and 600 degrees C and the resulting catalysts were tested on reaction of total oxidation of toluene. The solids were characterized by X-ray diffraction, thermal analysis, atomic absorption spectroscopy, Fourier transformed infrared spectroscopy, N(2) adsorption and H(2) temperature-programmed reduction. It was found that ZnCuAl materials are composed of copper and zinc oxides supported on alumina; while MnCuAl ones comprise basically spinel phases, which were not completely identified. The catalytic behavior of the calcined samples showed that Mn hydrotalcite calcined at 450 degrees C exhibited the best catalytic performance that corresponds to 100% toluene conversion into CO(2) at about 300 degrees C.

Hydrothermal synthesis of new wolframite type trimetallic materials and their use in oxidative dehydrogenation of propane.

With the aim of obtaining materials with properties for use as catalysts, two new trimetallic oxides containing Co or Ni and Mo and W were synthesized by a hydrothermal method, using milder conditions than those normally used for wolframite type solids. They were characterized by X-ray diffraction, Fourier transformed infrared spectroscopy, laser Raman spectroscopy, temperature-programmed reduction and atomic absorption spectroscopy, indicating that pure wolframite phases were formed. The X-ray diffraction studies confirmed the formation of the structure in the monoclinic system with cell parameters similar to nickel tungsten wolframite. The laser Raman and infrared spectra showed differences among the samples, mainly due to the incorporation of molybdenum atoms in the wolframite structure. Incorporation of molybdenum in the catalysts improved catalytic activity for propane oxidative dehydrogenation, and lower reaction temperatures were required in order to obtain similar propene yields as in bimetallic tungsten wolframites.