Copper(II) aza-bis(oxazoline) complex immobilized onto ITQ-2 and MCM-22 based materials as heterogeneous catalysts for the cyclopropanation of styrene

A copper(II) chiral aza-bis(oxazoline) homogeneous catalyst (CuazaBox) was anchored onto the external surface of MCM-22 and ITQ-2 structures, as well as encapsulated into hierarchical MCM-22. The transition metal complex loading onto the porous solids was determined by ICP-AES and the materials were also characterized by elemental analysis (C, N, H, S), FTIR, XPS, TG and low temperature N-2 adsorption isotherms. The materials were tested as heterogeneous catalysts in the benchmark reaction of cyclopropanation of styrene to check the effect of the immobilization procedure on the catalytic parameters, as well as on their reutilization in several catalytic cycles. Catalyst CuazaBox anchored onto the external surface of MCM-22 and ITQ-2 materials were more active and enantioselective in the cyclopropanation of styrene than the corresponding homogeneous phase reaction run under similar experimental conditions. This is due to the propylation of the acidic aza-Box nitrogen. HMCM-22 was nevertheless the best heterogeneous catalyst. Encapsulation of CuazaBox on post-synthesis modified MCM-22 materials led to low activities and enantioselectivities. But reversal on the stereochemical course of the reaction was observed, probably due to confinement effect. (C) 2013 Elsevier Inc. All rights reserved.

Epidemiologic transition in northern Angola: discussion of cumulative results from CISA (Health Research Centre of Angola)

The 41 years of armed conflict (1961 to 2002) resulted in a poor development of the health care and education infrastructures, and forced the relocation of people to safer places, namely major urban cities like Luanda. This phase was characterized by typical demographic, nutritional and epidemiological profiles. With the end of this period Angola has been repeatedly ranked as one of the three fastest growing economies in the world, and along with the social stabilization and globalization, the country is facing the introduction of new medical technologies, improvement of health sys-tems and services, better access to them, and overall better quality of life. These changes could also be translating into socio-cultural, demographic and nutritional changes which in turn may leading to changes in the epidemiological profile of the country. Thus, the emergence of non-communicable diseases are likely to become an increasingly im-portant public health problem in Angola. Also, considering that several infectious diseases persist, our weakened health system will have to face a double burden. Thus, disease surveillance data on non-communicable diseases to determine their prevalence and impact, along with the major behavioural risk factors like consumption of tobacco, alcohol, diets and physical inactivity are urgently needed.

Do fatigue, physical activity, handgrip strength and quality of life change between pre and post liver transplant?

Analisar: níveis de fadiga, força de preensão, HRQoL, níveis de actividade física. Será que se alteram em doentes PAF após o transplante de fígado? Dado que os níveis de actividade física se encontram abaixo dos valores mínimos recomendados deveria ser encontrada uma estratégia de aumento do tempo dispendido na actividade física leve a moderada idealmente no PRÉ TRANSPLANTE.

The Portuguese transition to democracy

On 25 April 1974 the Armed Forces Movement (MFA – Movimento das Forças Armadas) rose against the dictatorial regime that had governed Portugal for 48 years. This event was the beginning of a turbulent transition process that was to culminate in the approval of a new constitution in April 1976 and in the instauration of a Western style pluralist democracy. There are many political scientists and historians who note the original and unexpected nature of this transition; however, there are very many different interpretations with respect to the roles played by each of the actors in the process: the armed forces, the parties and political movements and the social forces/movements. The aim of this paper is to clarify this matter through an examination of the principal events of the revolution.

Optimising protocol of acquisition and post-processing procedures in the assessment of coronary artery disease by computed tomography

Coronary artery disease (CAD) is currently one of the most prevalent diseases in the world population and calcium deposits in coronary arteries are one direct risk factor. These can be assessed by the calcium score (CS) application, available via a computed tomography (CT) scan, which gives an accurate indication of the development of the disease. However, the ionising radiation applied to patients is high. This study aimed to optimise the protocol acquisition in order to reduce the radiation dose and explain the flow of procedures to quantify CAD. The main differences in the clinical results, when automated or semiautomated post-processing is used, will be shown, and the epidemiology, imaging, risk factors and prognosis of the disease described. The software steps and the values that allow the risk of developingCADto be predicted will be presented. A64-row multidetector CT scan with dual source and two phantoms (pig hearts) were used to demonstrate the advantages and disadvantages of the Agatston method. The tube energy was balanced. Two measurements were obtained in each of the three experimental protocols (64, 128, 256 mAs). Considerable changes appeared between the values of CS relating to the protocol variation. The predefined standard protocol provided the lowest dose of radiation (0.43 mGy). This study found that the variation in the radiation dose between protocols, taking into consideration the dose control systems attached to the CT equipment and image quality, was not sufficient to justify changing the default protocol provided by the manufacturer.

Modifications of MCM-22 zeolite through sequential post-synthesis treatments. Implications on the acidic and catalytic behaviour

Desilication and a combination of alkaline followed by acid treatment were applied to MCM-22 zeolite using two different base concentrations. The samples were characterised by powder X-ray diffraction, Al-27 and Si-29 MAS-NMR spectroscopy, SEM, TEM and low temperature N-2 adsorption. The acidity of the samples was study through pyridine adsorption followed by FTIR spectroscopy and by the analyses of the hydroxyl region. The catalytic behaviour, anticipated by the effect of post-synthesis treatments on the acidity and space available inside the two internal pore systems was evaluated by using the model reaction of m-xylene transformation. The generation of mesoporosity was achieved upon alkaline treatment with 0.05 M NaOH solution and practically no additional gain was obtained when the more concentrate solution, 0.1 M, was used. Instead, Al extraction takes place along with Si, as shown by Si-29 and Al-27 MAS-NMR data, followed by Al deposition as extraframework species. Samples submitted to alkaline plus acid treatments present distinct behaviour. When the lowest NaOH solution was used no relevant effect was observed on the textural characteristics. Additionally, when the acid treatment was performed on an already fragilized MCM-22 structure, due to previous desilication with 0.1 M NaOH solution, the extraction of Al from both internal pore systems promotes their interconnection, evolving from a 2-D to a 3-D porous structure. This transformation has a marked effect in the catalytic behaviour, allowing an increase of m-xylene conversion as a consequence of an easier and faster molecular traffic in the 3-D structure. On the other hand, the continuous deposition of extraframework Al species inside the pores leads to a shape selective effect that privileges the formation of the more valuable isomer p-xylene.

Liquid crystal beads constrained on thin cellulosic fibers: Electric field induced microrotors and N-I transition

We directly visualize the response of nematic liquid crystal drops of toroidal topology threaded in cellulosic fibers, suspended in air, to an AC electric field and at different temperatures over the N-I transition. This new liquid crystal system can exhibit non-trivial point defects, which can be energetically unstable against expanding into ring defects depending on the fiber constraining geometries. The director anchoring tangentially near the fiber surface and homeotropically at the air interface makes a hybrid shell distribution that in turn causes a ring disclination line around the main axis of the fiber at the center of the droplet. Upon application of an electric field, E, the disclination ring first expands and moves along the fiber main axis, followed by the appearance of a stable "spherical particle" object orbiting around the fiber at the center of the liquid crystal drop. The rotation speed of this particle was found to vary linearly with the applied voltage. This constrained liquid crystal geometry seems to meet the essential requirements in which soliton-like deformations can develop and exhibit stable orbiting in three dimensions upon application of an external electric field. On changing the temperature the system remains stable and allows the study of the defect evolution near the nematic-isotropic transition, showing qualitatively different behaviour on cooling and heating processes. The necklaces of such liquid crystal drops constitute excellent systems for the study of topological defects and their evolution and open new perspectives for application in microelectronics and photonics.

Reply to "Comment on 'Effect of polydispersity on the ordering transition of adsorbed self- assembled rigid rods'"

We comment on the nature of the ordering transition of a model of equilibrium polydisperse rigid rods on the square lattice, which is reported by Lopez et al. to exhibit random percolation criticality in the canonical ensemble, in sharp contrast to (i) our results of Ising criticality for the same model in the grand canonical ensemble [Phys. Rev. E 82, 061117 (2010)] and (ii) the absence of exponent(s) renormalization for constrained systems with logarithmic specific-heat anomalies predicted on very general grounds by Fisher [Phys. Rev. 176, 257 (1968)].

Somewhere near reality: artistic portrayal of violence in post WWII British realistic drama

ABSTRACT - I will explore and present the portrayal of violence in some British plays that were staged between 1951 and 1965, in order to discuss the role, impact and aim of its representation. Thus, I will consider John Whiting’s Saint’s Day (1951), Ann Jelicoe’s The Sport of my Mad Mother (1956), Arnold Wesker (Chicken Soup with Barley (1958), Harold Pinter’s Birthday Party (1958), David Rudkin’s Afore Night Come (1962) and Edward Bond’s Saved (1965). My aim is to discuss the way how theatre in the post WWII changed the traditional ways of representing violence. On one hand, violence and reality became more and more familiar and domestic, permitting a representation of multiple and non-agonic violence; and, on the other hand, the violence that was depicted often changed the way one perceived reality itself, being part of a socially engaged artistic attitude.

Formación de profesores post Bolonia: los desafíos de un proceso en dos etapas

En los últimos años, las políticas de formación de profesores se han convertido en un foco de interés para gobernantes, investigadores y profesionales de la educación. En Portugal, como en otros países europeos, la reestructuración de la formación de profesores estuvo marcada por las políticas, directrices y tendencias de la Comisión Europea, adecuándolas a las especificidades propias de la cultura e historia nacionales. Actualmente, la formación de profesores para los primeros años (0-12) se realiza en instituciones de enseñanza superior, bajo una estructura de dos etapas, constituida por el primer ciclo (licenciatura en Educación Básica) y el segundo ciclo (maestros en educación de infancia y/o ciclo de Enseñanza Básica), con una duración de 4,5 a 5 años. Esta organización en dos etapas ha traído nuevos desafíos a la coherencia y consistencia de los cursos de formación, sobre todo, por lo que respecta a la articulación de la formación académica con la formación práctica. Los problemas generados se vuelven especialmente relevantes en el 6º semestre de la licenciatura en Educación Básica, periodo de transición entre la conclusión de una etapa y el inicio de otra. En este artículo, relatamos el recorrido realizado en la organización de la formación en Educación Básica en una escuela superior de educación en Portugal. El proyecto duró 4 años e incidió en la orientación, organización y procesos de apoyo a la iniciación a la práctica profesional en el 6º semestre del curso. En este proceso, la participación e implicación de los estudiantes, a través de la evaluación de la formación, fue el rasgo fundamental y distintivo.