Abstract Introduction. In recent decades, endovascular therapy in abdominal aortic aneurysms has gained a representative role in surgical scenarios, which motivated us to learn about the results of this procedure in our population. Methods. Retrospective analytical study, which included the first 50 cases of abdominal aortic aneurysms with endovascular therapy, in the city of Manizales, Colombia, between 2015 and 2021. The study population was described as the relationship between pre-surgical history and post-operative complications, hospital stay and mortality. Results. The average age was 73 years, the predominant sex was female (72%), the fusiform aneurysm was the most frequent type (63.3%), with an average diameter of 70 mm (± 17.3 mm). In relation to history, the most frequent was arterial hypertension (86%), finding an association between the presence of chronic obstructive pulmonary disease and arterial hypertension with complications. A relationship was also found between the creatinine value and complications. Early complications were mild in most cases (30.6%), unlike late complications, which were mainly serious (12.5%), associated with a mortality of 10.2% and a hospital stay average of 10.8 days (median of 5 days). Conclusions. The analyzed population has a high burden of morbidity, in which factors such as pre-surgical medical history and renal function are associated with greater post-surgical morbidity and mortality.

Resumen Introducción. En las últimas décadas, la terapia endovascular en aneurismas aórticos abdominales ha ganado un papel representativo en los escenarios quirúrgicos, lo que nos motivó a conocer los resultados de este procedimiento en nuestra población. Métodos. Estudio analítico retrospectivo en el cual se incluyeron los primeros 50 casos de aneurismas aórticos abdominales con terapia endovascular, en la ciudad de Manizales, Colombia, entre los años 2015 y 2021. Se describió la población estudiada, la relación de los antecedentes prequirúrgicos con las complicaciones posoperatorias, la estancia hospitalaria y la mortalidad. Resultados. La edad promedio fue de 73 años, el sexo predominante fue el femenino (72 %), el aneurisma fusiforme fue el tipo más frecuente (63,3 %), con un diámetro promedio de 70 mm (+/- 17,3 mm). En relación con los antecedentes, el más frecuente fue hipertensión arterial (86 %), encontrándose una asociación entre la presencia de enfermedad pulmonar obstructiva crónica e hipertensión arterial con las complicaciones. Se encontró también relación entre el valor de creatinina con las complicaciones. Las complicaciones tempranas fueron de carácter leve en la mayoría de los casos (30,6 %), a diferencia de las tardías, que fueron principalmente graves (12,5 %), asociadas a una mortalidad del 10,2 % y una estancia hospitalaria promedio de 10,8 días (mediana de 5 días). Conclusiones. La población analizada tiene una alta carga de morbilidad, en la cual factores como los antecedentes médicos prequirúrgicos y la función renal, se asocian con una mayor morbilidad postquirúrgica y mortalidad.

RESUMEN Introducción: Los procesos de acreditación de la calidad de los programas de formación de médicos tienen importancia en cuanto al impulso que pueden dar a la formación de mejores profesionales. El reconocimiento de la calidad educativa de un determinado programa o carrera por parte de los organismos facultados, como la Agencia Nacional de Evaluación y Acreditación de la Educación Superior (ANEAES) es una garantía del cumplimiento de los criterios mínimos de calidad establecidos. Sin embargo, la calidad de un postgrado no solo es valorada por el cumplimiento de los criterios de calidad mínimos establecidos por los organismos encargados, sino por otros criterios como serían la percepción de los estudiantes, actuales y graduados sobre la calidad de la formación ofrecida por el mismo. Objetivos: El presente trabajo tiene como objetivo general estudiar la calidad de la formación en el Postgrado de Especialización en Pediatría Clínica de la FCM-UNA, a partir de las percepciones de sus estudiantes, actuales y graduados. Materiales y métodos: La metodología se enmarca en la tradición cualitativa de investigación social y en su instrumentación se incluye la realización de entrevistas semiestructuradas aplicadas a los estudiantes actuales (residentes) y graduados (egresados) del programa, así como el desarrollo, implementación y análisis de matrices, con la discusión de los resultados correspondientes a cada una de ellas. Resultados: Los resultados obtenidos muestran que la mayor parte de los estudiantes, actuales y egresados, del Postgrado de Especialización en Pediatría Clínica de la FCM UNA, perciben que la formación en este es de buena a mediana calidad. Los factores que inciden positivamente en la percepción de la calidad de la formación son: el ámbito de desarrollo del programa, el plan de estudios, las actividades académicas, la calidad de la composición y el desempeño del plantel docente, así como las relaciones interpersonales, tanto con los docentes como con sus pares; con algunas excepciones puntuales. La inclusión en el currículum de los aspectos relativos a la responsabilidad social universitaria también tuvo una incidencia positiva. Los factores que incidieron negativamente en la percepción de la calidad de la formación fueron: la carga horaria excesiva, el sistema de evaluación exigente, las falencias en la infraestructura y las tareas de asistencia social, en desmedro de la optimización del tiempo para la formación. En lo referente a la incidencia de la pandemia de COVID 19 en la calidad de la formación, las percepciones fueron dispares al interior de los casos de estudio que cursaron el postgrado durante la misma, con elementos negativos y llamativamente algunos elementos positivos. A la hora de sopesar en qué medida los factores positivos y negativos incidieron globalmente en la percepción de la calidad de la formación, se evidenció que, a pesar del reconocimiento de la existencia de varios factores negativos, los primeros primaron sobre los segundos. Esto hace que la mayoría de los estudiantes actuales y egresados manifiesten su satisfacción con el postgrado y los graduados con su desempeño autónomo al cumplir con sus expectativas. Conclusión: La mayor parte de los estudiantes, actuales y graduados del Postgrado de especialización en Pediatría Clínica de la FCM UNA, perciben que la formación en el mismo es de buena a mediana calidad, con aspectos a mejorar que son mencionados en las recomendaciones.

ABSTRACT Introduction: The quality accreditation processes of medical training programs are important in terms of the boost they can give to the training of better professionals. Recognition of the educational quality of a certain program or career by authorized bodies, such as the National Agency for the Evaluation and Accreditation of Higher Education (ANEAES) is a guarantee of compliance with the minimum established quality criteria. However, the quality of a postgraduate course is not only assessed by compliance with the minimum quality criteria established by the bodies in charge, but by other criteria such as the perception of current and graduate students about the quality of the training offered by the same. Objectives: The general objective is to study the quality of training in the Postgraduate Specialization in Clinical Pediatrics of the FCM-UNA, based on the perceptions of its current and graduate students. Materials and methods: The methodology is part of the qualitative tradition of social research and its instrumentation includes semi-structured interviews applied to current students (residents) and graduates of the program, as well as the development, implementation and analysis of matrices, with the discussion of the results corresponding to each of them. Results: The results obtained show that most of the students, current and graduates, of the Postgraduate Specialization in Clinical Pediatrics of the FCM UNA, perceive that the training is of good to medium quality. Factors that positively affect the perception of the quality of training are: the scope of development of the program, the study plan, academic activities, quality of the composition and performance of the teaching staff, as well as interpersonal relationships, both with teachers and with their peers; with some specific exceptions. The inclusion in the curriculum of aspects related to university social responsibility also had a positive impact. Factors that negatively affected perception of the quality of training were: excessive workload, the demanding evaluation system, shortcomings in the infrastructure and the tasks of social service, to the detriment of time dedicated to optimizing training. Regarding the incidence of the COVID 19 pandemic on the quality of training, perceptions were uneven within the case studies that took the postgraduate course during it, with negative elements and strikingly some positive elements. When weighing up the extent to which the positive and negative factors had a global impact on the perception of the quality of training, it was shown that, despite the recognition of the existence of several negative factors, the former prevailed over the latter. This makes the majority of current students and graduates express their satisfaction with the postgraduate course and graduates with their autonomous performance in meeting their expectations. Conclusion: Most of the students, current and graduates of the Postgraduate specialization in Clinical Pediatrics of the FCM UNA, perceive that the training in it is of good to medium quality, with aspects to improve that are mentioned in the recommendations.

Resumen La época colonial en la ciudad de Cuenca (Ecuador) dejó huellas indelebles en la urbe, así como diversas transformaciones culturales y arquitectónicas que son objeto de particular interés. El presente artículo expone el análisis y la propuesta de intervención sobre una edificación colonial del centro histórico de la ciudad, con base en la lectura estratigráfica muraria y el dictamen patológico. A partir de estos insumos se evidencian: tres etapas constructivas del bien entre 1816 y 2017; también, el predominio de lesiones mecánicas, físicas y antrópicas, como constantes del detrimento del paisaje urbano histórico de la ciudad, y la demanda de intervenciones emergentes y conservativas. En consecuencia, se diseñan intervenciones constructivas específicas bajo la orientación teórica de corte convencional (español e italiano) y la práctica asociada al conocimiento constructivo local. Al mismo tiempo, se apuesta por la recuperación del patrimonio, con la perspectiva de la adaptación a la contemporaneidad, pero sin descuidar la rigurosidad técnica.

Abstract The colonial period in the city of Cuenca (Ecuador) left indelible traces in the city, as well as diverse cultural and architectural transformations that are of particular interest. This article presents the analysis and intervention proposal on a colonial building of the historic center, based on the mural stratigraphic reading and the pathological opinion. From these inputs, the following are evidenced: three constructive stages of the property between 1816 and 2017; the predominance of mechanical, physical and anthropic injuries as constants of the detriment of the historical urban landscape of the city, and the demand for emerging and conservative interventions. Consequently, specific constructive interventions are designed under the conventional theoretical orientation (Spanish and Italian), and the practice associated with local constructive knowledge. At the same time, there is a commitment to the recovery of heritage, from the perspective of adaptation to contemporaneity without neglecting technical rigor.

Resumen Introducción. El carcinoma del glomus carotideo es infrecuente y se presenta en el 6 % de los paragangliomas carotideos. Suele haber dificultad en su diagnóstico preoperatorio y no se diferencia fácilmente de su contraparte benigna, lo que puede conllevar a complicaciones quirúrgicas. Este trabajo describe la experiencia en su abordaje clínico y quirúrgico en una serie de casos, además de una revisión de la literatura profundizando en su diagnóstico, abordaje terapéutico, sobrevida y mortalidad. Métodos. De los pacientes operados por glomus carotideos durante un periodo de 20 años, se identificaron aquellos llevados a cirugía por carcinoma. Se realizó una búsqueda bibliográfica extensa en PubMed, haciendo énfasis en diagnóstico y tratamiento. Resultados. De un total de 139 pacientes sometidos a cirugía de resección de tumor del cuerpo carotideo, tres pacientes (2,2 %) presentaron carcinoma. Dos tenían metástasis cervicales y uno metástasis hepáticas. Uno presentaba glomus bilateral asociado a trastorno genético de origen familiar. Se realizó cirugía y adyuvancia en todos los casos. Discusión. El diagnóstico diferencial preoperatorio entre glomus benigno y maligno es difícil, por lo cual deben buscarse hallazgos clínicos o factores de riesgo que puedan sugerir malignidad. Las imágenes pocas veces muestran características claras de invasión vascular. Siempre que sea posible, en el tratamiento del cáncer del glomus carotideo, debe realizarse resección quirúrgica, acompañada de un vaciamiento funcional de cuello, dejando la radioterapia, la quimioterapia y la hormonoterapia como terapias adyuvantes.

Abstract Introduction. Carcinoma of the carotid glomus is rare and occurs in 6% of carotid paragangliomas. There is often difficulty in its preoperative diagnosis, and it is not easily differentiated from its benign counterpart, which can lead to surgical complications. This study describes the experience in its clinical and surgical approach in a series of cases, as well as a review of the literature of its diagnosis, therapeutic approach, survival, and mortality. Methods. Of the patients operated for carotid glomus over a 20-year period, those undergoing surgery for carcinoma were identified. An extensive literature search was conducted in PubMed, with an emphasis on diagnosis and treatment. Results. Out of a total of 139 patients who underwent carotid body tumor resection surgery, three patients (2.2%) had carcinoma. Two had cervical metastases and one had liver metastases. One had bilateral glomus associated with a genetic disorder of familial origin. Surgery and adjuvant surgery were performed in all cases. Discussion. The preoperative differential diagnosis between benign and malignant glomus is difficult, for which clinical findings or risk factors that may suggest malignancy should be sought. Images rarely show clear features of vascular invasion. Whenever possible in the treatment of carotid glomus cancer, surgical resection should be performed, accompanied by a functional neck dissection, leaving radiotherapy, chemotherapy, and hormone therapy as adjuvant therapies.

ABSTRACT Since aging naturally leads to an imbalance in the diversity and quantity of microorganisms present in the intestine, older people are particularly vulnerable to diseases associated with the gastrointestinal tract. Thus, supplementing the diet of elderly persons with non-digestible oligosaccharides and polysaccharides (OPND) has gained scientific relevance. Supplementation aims to prevent and (partially) revert the negative changes in intestinal microbiota due to aging. It has been observed that OPND supplementation in older adults provides several benefits, including an improvement in the immune system, increased calcium absorption, a reduction in the incidence of allergies, a reduction in constipation and a decrease in blood levels of cholesterol and glucose. Because the effects of OPND supplementation in older adults has been scarcely discussed in the scientific literature in the Spanish language, the purpose of this review is to address the issue with emphasis on the Chilean and Latin-American reality. The article promotes the incorporation of OPND in processed food and feeding programs specifically designed for older people in Latin America.

RESUMEN Los adultos mayores son especialmente vulnerables a sufrir enfermedades asociadas al tracto gastrointestinal, ya que el envejecimiento conlleva naturalmente a un desbalance en la diversidad y cantidad de los microorganismos presentes en el intestino. Por ello, la suplementación de su dieta con oligosacáridos y polisacáridos no digestibles (OPND) ha cobrado gran relevancia científica. Esto, con el propósito de prevenir y revertir, en parte, los cambios negativos en la microbiota intestinal derivados del envejecimiento. Se ha observado que la suplementación de OPND en adultos mayores genera variados beneficios, entre los que destacan una mejora en el sistema inmune, una mayor absorción de calcio, reducción en la incidencia de alergias, reducción de la constipación y una disminución en los niveles de glicemia y colesterol sanguíneos. Debido a que, los efectos del consumo de OPND en adultos mayores han sido escasamente discutidos en la literatura científica en idioma castellano, el propósito de esta revisión es abordar el tema haciendo énfasis en la realidad chilena y latinoamericana. Ello, con miras a fomentar la incorporación de OPND en alimentos y programas de alimentación dirigidos específicamente a personas de la tercera edad.

ABSTRACT The effect of suckling restriction with nasal flaps on Angus and Creole calves and dam's performance fixed time artificially inseminated (FTAI) in an arid zone of Argentina was evaluated. The first experiment was carried out with 146 multiparous cows with calf at foot and 76.2±3.0 days postpartum, assigned to four treatments: Angus cows (n=37) and Creole cows (n=37) with restricted suckling (RS, calves with nasal flaps for 14 days) and Angus (n=35) and Creole (n=37) cows with non-restricted suckling calves (Control, C). On Day 0, the cows received an intravaginal device with progesterone for 8 days and nasal flaps were placed to calves. The FTAI was performed on Day 10 and the pregnancy diagnosis was made at 35 days by ultrasound. In calves, weight was measured on Days 0 and 14 and at weaning (6 months of age). The pregnancy rate was similar between treatments (RS=51.0%; C=53.0%), regardless of breed. At weaning, calves in treatment C were 12.2 kg heavier than calves in RS. The second experiment was performed with 109 multiparous Angus cows with calf at foot with 59.9 ± 0.7 days postpartum, assigned to treatments RS and C. There was no effect on pregnancy rate (RS=66.0%; C=72.0%) and calves from treatment C were 8.6 kg heavier at weaning than those from RS. The results showed that in multiparous cows, the restriction of suckling combined with a hormonal treatment for FTAI does not improve the pregnancy rate and negatively affects the weight of the calves at weaning.

RESUMEN Se evaluó el efecto de la restricción del amamantamiento con tablilla nasal sobre la productividad de terneros y vacas Angus y Criolla con inseminación artificial a tiempo fijo (IATF) en una zona árida de Argentina. El primer experimento se hizo con 146 vacas multíparas con cría al pie en pastoreo y con 76.2±3.0 días posparto, asignadas a cuatro tratamientos: vacas Angus (n=37) y Criolla (n=37) con amamantamiento restringido (AR, terneros con tablilla nasal durante 14 días) y vacas Angus (n=35) y Criolla (n=37) con terneros con amamantamiento ad libitum (Control, C). El Día 0, las vacas recibieron un dispositivo intravaginal con progesterona durante 8 días y a los terneros se les colocó la tablilla nasal. La IATF se realizó el Día 10 y el diagnóstico de gestación se realizó a los 35 días por ultrasonografía. En los terneros se determinó el peso a los Días 0, 14 y al destete (6 meses de edad). El porcentaje de preñez fue similar entre tratamientos (AR=51.0%; C=53.0%), independientemente de la raza. Al destete, los terneros del tratamiento C fueron 12.2 kg más pesados que los terneros del AR. El segundo experimento se hizo con 109 vacas Angus multíparas con cría al pie con 59.9±0.7 días posparto, asignadas a los tratamientos AR y C. No hubo efecto sobre el porcentaje de preñez (AR=66.0%; C=72.0%) y los terneros del tratamiento C fueron 8.6 kg más pesados al destete que los del AR. Los resultados demostraron que en vacas multíparas, la restricción del amamantamiento combinado con un tratamiento hormonal para IATF no mejora el porcentaje de preñez y afecta negativamente el peso de los terneros al destete.

The effect of noble metal catalysts supported on an ionic exchange resin for the enantioselective hydrogenation of ethyl pyruvate to ethyl lactate was studied. High activity and moderate enantioselectivity levels were obtained. Pt was the best enantioselective metallic phase, followed by Pd and Au; Rh was the less enantioselective metallic phase. The effect of the active site was evaluated for the most enantioselective catalyst: 2Pt-WA30 (prefix indicates the metal loading). A novel method for sintering the Pt metal particles by nitriles reduction was used, and a controlled migration of the metal particles to the surface layers was observed. There existed an optimal particle size with maximization of the enantiomeric excess, corresponding to 24 h sintering. The hydrogenation of ethyl pyruvate to ethyl lactate was found to be structure-sensitive and the importance of the metal particle size for the adsorption of the chiral modifier was proved. Two different chirality induction methods were tried for the 2Pt-WA30 catalyst: (i) the addition of the chiral modifier (CM) to the reaction media, or (ii) the modification of the catalyst in a swelling medium prior to the reaction in order to encapsulate CM. Lower activity but higher enantioselectivity levels were obtained with method (ii). Finally, the reuse of the catalysts was also assessed by means of consecutive reaction tests.

RESUMEN Las tarjetas de adquisición se servirán de la actualización del LHCb, que tendrá lugar en el periodo entre 2018 y 2019, durante el Long Shutdown 2 de los experimentos del CERN. Estas mejoras apuntan a la configuración y reestructuración de las técnicas de adquisición de datos, debido al incremento en la luminosidad y correspondientemente con su energía de centro de masa actual. Por lo tanto, se documenta la condición del detector, sus técnicas de adquisición y sus protocolos. Se hará énfasis en las Fibras de Centelleo (SciFi), uno de los futuros subdetectores del LHCb, encargado del reconocimiento de patrones de trazas, basado en los cruces o impactos que ocurren sobre sus fibras, además del registro de eventos significativos en la transmisión de datos. Este artículo presenta paso a paso las modificaciones aplicadas a los códigos para pasar del Modo Estándar al Modo de Bus Ampliado, incrementando la tasa de datos mediante la reducción de bits de control, para acrecentar el número de información analizable sobre los eventos.

ABSTRACT Data acquisition boards will take advantage of the LHCb upgrade between 2018 and 2019 during the Long Shutdown 2 of CERN experiments. These improvements aim to the configuration and re-structuring of data acquisition techniques in terms of increased luminosity and its current center-of-mass energy. Accordingly, we documented the current condition of the detector, its acquisition techniques and protocols. This paper will emphasize the Scintillating Fibers (SciFi) detector, which is one of LHCb's future sub-detectors that is in charge of trace pattern recognition by recording significant events in data transmission. It will also show step by step the modifications made to the codes to move from a Standard Mode to a Wide Bus Mode, increasing data rate by reducing control bits. This improvement will enlarge the amount of analyzable event data.

Resumen La importancia del liderazgo de los directivos como uno de los elementos que contribuyen a la calidad de la educación hace que su valoración resulte un asunto de enorme interés. En este estudio de tipo descriptivo, con empleo del método análisis documental, nos planteamos como objetivo caracterizar el liderazgo en instituciones de educación superior, porque es un reto que las instituciones de educación tienen como premisa fundamental en nuestra sociedad contemporánea; este incluye el guiar, inspirar e impulsar a los seguidores a realizar acciones éticas con valores y responsabilidad social, por ello el liderazgo en el ámbito de la educación superior deberá tener estas características mencionadas con el fin de mejorar la sociedad. A la hora de plantear la eficacia de las instituciones de educación superior y la calidad de este ámbito se suele considerar al liderazgo como uno de los factores clave. En términos generales podemos concluir que el liderazgo sigue siendo uno de los temas más controvertidos en el campo de la elaboración teórica, en el de las políticas educativas y prácticas concernientes a la organización de las instituciones educativas en el ámbito superior.

Abstract The importance of the leadership of the directors as one of the elements that contribute to the quality of education makes their assessment an issue of enormous interest. Leadership in higher education institutions is undoubtedly a challenge that educational institutions have as a fundamental premise in our contemporary society, this includes guiding, inspiring and encouraging followers to perform ethical actions with values and social responsibility, therefore the Leadership in the field of higher education should have these characteristics mentioned in order to improve society. When considering the effectiveness of higher education institutions and the quality of this area, leadership is usually considered one of the key factors. However, leadership remains one of the most controversial issues in the field of theoretical elaboration, in educational policies and practices concerning the organization of educational institutions in the higher field.

The influence of the kind of metal precursor and the sequence of impregnation on the properties of Pd-Ni catalysts was evaluated during the test reaction of selective hydrogenation of styrene to ethylbenzene by means of physicochemical characterization. The focus was put on the final hydrogenating activity and the resistance to deactivation by sulfided compounds (thiophene). The used techniques of characterization were ICP, XPS, XDR, TPR, CO chemisorption and TEM. XPS results indicated the presence of different Pd species: Pdδ-, Pdº and Pdδ+. In the case of the Ni containing catalysts, Niº and NiO species were also detected. These palladium and nickel species would be responsables of the variation of activity and sulfurresistance of the catalysts. NiClPd catalysts had a higher resistance to deactivation by sulfur poisoning. This was associated to a higher concentration of Pdη+ClxOy species that would prevent the adsorption of thiophene by both steric and electronic effects. It could also be due to the lower concentration of Pdº and Niº on these catalysts, as compared to those shown by the PdNiCl catalysts. Both the Pdº and Niº species are more prone to poisoning because of their higher electronic availability.

The glycerol hydrogenolysis reaction was performed in a continuous flow trickle bed reactor using a water glycerol feed and both copper chromite and Cu/Al2O3 catalysts. The commercial copper chromite had a higher activity than the laboratory prepared Cu/Al2O3 and was used for most of the tests. Propylene glycol was the main product with both catalysts, acetol being the main by-product. It was found that temperature is the main variable influencing the conversion of glycerol. When the state of the glycerol-water reactant mixture was completely liquid, at temperatures lower than 190 ºC, conversion was low and deactivation was observed. At reaction temperatures of 210-230 ºC the conversion of glycerol was complete and the selectivity to propylene glycol was stable at about 60-80% all throughout the reaction time span of 10 h, regardless of the hydrogen pressure level (1 to 20 atm). These optimal values could not be improved significantly by using other different reaction conditions or increasing the catalyst acidity. At higher temperatures (245-250 ºC) the conversion was also 100%. Under reaction conditions at which copper chromite suffered deactivation, light by-products and surface deposits were formed. The deposits could be completely burned at 250 ºC and the catalyst activity fully recovered.

Low-cost tungsten monometallic catalysts containing variable amounts of metal (4.5, 7.1 and 8.5%W) were prepared by impregnating alumina with ammonium metatungstate as an inexpensive precursor. The catalysts were characterized using ICP, XPS, XRD, TPR and hydrogen chemisorption. These techniques revealed mainly WO3-Al2O3 (W6+) species on the surface. The effects of the content of W nanoparticles and reaction temperature on activity and selectivity for the partial hydrogenation of 3-hexyne, a non-terminal alkyne, were assessed under moderate conditions of temperature and pressure. The monometallic catalysts prepared were found to be active and stereoselective for the production of (Z )-3-hexene, had the following order: 7.1WN/A > 8.5 WN/A ≥ 4.5 WN/A. Additionally, the performance of the synthesized xWN/A catalysts exhibited high sensitivity to temperature variation. In all cases, the maximum 3-hexyne total conversion and selectivity was achieved at 323 K. The performance of the catalysts was considered to be a consequence of two phenomena: a) the electronic effects, related to the high charge of W (+6), causing an intensive dipole moment in the hydrogen molecule (van der Waals forces) and leading to heterolytic bond rupture; the H+ and H- species generated approach a 3-hexyne adsorbate molecule and cause heterolytic rupture of the C≡C bond into C- = C+; and b) steric effects related to the high concentration of WO3 on 8.5WN/A that block the Al2O3 support. Catalyst deactivation was detected, starting at about 50 min of reaction time. Electrodeficient W6+ species are responsible for the formation of green oil at the surface level, blocking pores and active sites of the catalyst, particularly at low reaction temperatures (293 and 303 K). The resulting best catalyst, 7.1WN/A, has low fabrication cost and high selectivity for (Z )-3-hexene (94%) at 323 K. This selectivity is comparable to that of the classical and more expensive industrial Lindlar catalyst (5 wt% Pd). The alumina supported tungsten catalysts are low-cost potential replacements for the Lindlar industrial catalyst. These catalysts could also be used for preparing bimetallic W-Pd catalysts for selective hydrogenation of terminal and non-terminal alkynes.

El presente trabajo trata de establecer una relación entre las comunidades de Cactáceas y su distribución en las vertientes occidentales de los Andes del Perú. Para ello empleamos distintos valores climáticos de precipitación y evapotranspiración potencial, y los índices climáticos de termicidad y aridez. Sobre una matriz con la composición florística de las comunidades aplicamos el índice de Sørensen obteniendo un dendrograma que explica cómo se agrupan las comunidades según provincias biogeográficas y pisos bioclimáticos. Aplicando sobre las distintas localidades seleccionadas un Análisis de Componentes Principales (ACP) podemos deducir cómo se agrupan en función de la altitud y los valores e índices climáticos. Las poblaciones de Cactáceas situadas al norte del paralelo 8°Sur son las más influidas por la humedad aportada por la corriente de El Niño; bajo el paralelo 8°Sur, las localidades situadas en las vertientes occidentales andinas dependen de la escasa humedad estival (HE), aunque en el sur también puede ser evidente la invernal (HI) al recibir las lluvias de depresiones aisladas que se desprenden de borrascas sub-antárticas entre julio y agosto; no obstante, los andenes de cultivo ancestrales reflejan un clima más húmedo que el actual. En la costa y áreas basales próximas al desierto abiótico, la aridez es muy elevada aunque aún están presentes las comunidades con Neoraimondia arequipensis. Las comunidades situadas al norte del paralelo 8° Sur pertenecen a la provincia biogeográfica Pacífica, las del centro a la provincia Ancashino-Paceña, las de los departamentos de Arequipa, Moquegua y Tacna, a la provincia Oruro-Arequipeña, y las del Desierto Pacífico a la provincia Limeño-Ariqueña.

Using climatic values of precipitation and potential evapotranspiration, as well as climate indices of thermicity and aridity, in this work we try to establish a relationship between cactus communities and their distribution in the western slopes of the Peruvian Andes. Using the Sørensen index on a matrix with the floristic composition of plant communities, we obtained a dendrogram that explains their grouping according to biogeographic provinces and bioclimatic belts. Using a Principal Component Analysis (PCA) on selected localities, we can infer how they are grouped according to the altitudinal gradient and climatic values and indices. Cactus populations located north of the 8° parallel south are the most influenced by the humidity provided by El Niño stream; those populations south of the 8° parallel south, on the western slopes of the Andes, depend on the low summer humidity (HE), although it can also be evident the winter humidity (HI) due to rainfalls of isolated depressions that emerge from sub-Antarctic storms between July and August. However, the crop terraces of ancestral cultures reflect a more humid ancient climate. In the coast and basal areas of the Andes, next to the abiotic desert, the aridity is very high, although communities with Neoraimondia arequipensis are still present. Communities located north of the 8° parallel south belong to the Pacific biogeographic province, those of the central Peru belong to the Ancash-La Paz province, those of the Arequipa, Moquegua and Tacna departments to the Oruro-Arequipa province, and finally those communities of the Pacific Desert belong to the Lima-Arica province.

A study of the different hydrocarbon reactions over Ni doped WO3-ZrO2 catalysts was performed. Ni was found as NiO at low Ni concentration while at high Ni concentrations a small fraction was present as a metal. For both cases, Ni strongly modified total acidity and concentration of strong acid sites. In the cyclohexane dehydrogenation reaction, Ni addition promotes both benzene and methyl cyclopentane production. The hydroconversion activity (n-butane and n-octane) increases with the augment of total acidity produced by Ni. The selectivity to reaction products is modified according to the acid strength distribution changes produced by Ni addition.

Two complexes of Rh(I) and Pd(II) with chloride and tridecylamine ligands were obtained and characterized by Elementary Analysis and by XPS and FTIR spectroscopies. Complexes anchored on γ-Al2O3 were tested in the styrene semi-hydrogenation reaction carried out in the absence or presence of a sulfur poison. Although both low loaded catalysts were highly selective, the Pd(II) complex was three times more active than the Rh(I) complex. The rhodium complex was more sulfur resistant but less active than the palladium complex. Differences in conversion and sulfur resistance between both complexes could be related to electronic and/or geometric effects.