Síntesis estereoselectiva en fullerenos: propiedades y aplicaciones fotoelectroquímicas

Tesis de la Universidad Complutense de Madrid, Facultad de Ciencias Químicas, leída el 11-04-2019After the discovery of fullerenes, carbon nanotubes and graphene, the classical allotropes of carbon were enriched with new structures and new potential applications. C60, with its singular spherical shape, its size (~1nm) and its remarkable electronic and photophysical properties, has emerged as a promising material for many potential applications in materials, nanotechnology and biomedical sciences. Objectives 1. Synthesis and electronic properties of fullerenes-fused unsaturated carbocyclesWe will extend the scope of asymmetric phosphine-catalysed cycloaddition of allenoates onto fullerenes through the variation of all the elements involved in the reaction. In addition, the intrinsic electronic mobility of these fullerenic derivatives will be measured with the objective of evaluating the influence of the optical purity on this property. 2. Reversible stereodivergent cycloaddition of a helicene derivative onto [60]fullerene: a chiral resolution strategyWe will try to take advantage of the stereoselective and reversible covalent fullerene chemistry as a tool for the resolution of racemates. For this purpose, enantioselective pyrrolidino[60]fullerenes will be prepared from a racemic iminoester derived from [6]helicene...Con el descubrimiento de los fullerenos por H. W. Kroto, R. F. Curl y R. E. Smalley en 1985, se enriqueció la variedad de alótropos del carbono. El C60, con su singular forma esférica, su tamaño (~1nm) y sus destacables propiedades electrónicas y fotofísicas, surgió como un material prometedor para muchas aplicaciones, tanto en materiales y nanotecnología como en ciencias biomédicas. Objetivos 1. Síntesis y propiedades electrónicas de derivados carbocíclicos insaturados fusionados a fullerenos Extenderemos la metodología de la reacción de cicloadición asimétrica de alenoatos sobre fullerenos catalizada por fosfinas mediante la variación de todos los elementos que intervienen en la reacción. Además, se llevará a cabo la medida de la movilidad electrónica intrínseca de estos derivados fullerénicos y se evaluará cómo afecta la pureza óptica a dicha propiedad. 2. Cicloadición estereodivergente reversible de un derivado de heliceno sobre el [60]fullereno: una estrategia de resolución quiral Realizaremos el estudio de la reversibilidad en la química covalente del fullereno como herramienta para la resolución de racematos. Para ello, se prepararán fulleropirrolidinas enantioselectivas a partir de un iminoéster racémico derivado de [6]heliceno...Fac. de Ciencias QuímicasTRUEunpu

Educación para el desarrollo

Agradecemos a la dirección del «II Foro Iberoamérica en la Escena Económica Internacional: Inversiones y Educación para el Desarrollo», D. Antonio Pastor, así como al Centro de Estudios Iberoamericanos de la Universidad Rey Juan Carlos, la invitación para participar en este foro. Intentaremos aportar algunas reflexiones, producto de la experiencia de más de veinte años de nuestra institución, Fomento de Centros de Enseñanza, en el asesoramiento para la implantación y el desarrollo de proyectos educativos a otras instituciones educativas, públicas y privadas de países iberoamericanos, que han sido un instrumento de cooperación para el desarrollo

Synthesis of modified fullerenes for oxygen reduction reactions

In the search for carbon based catalysts for Oxygen Reduction Reactions (ORR), two different classes of fullerene hybrids and metal free fullerene derivatives have been prepared by highly selective metal- and organo-catalyzed synthetic methods. They were included as both electron acceptors and catalysts in polymer-based photo-electrochemical cell,fully demonstrating electrocatalytic activity. Remarkably, the activity of the metal free fullerenes proved to be as high as that observed for metallofullerenes based on noble metals, and up to ten-fold higher than by using PCBM

La gestión de cuentas por cobrar y su influencia en la liquidez de la empresa Grupo Eléctrico Gonzales S.A.C., Lima, 2018

El objetivo de la investigación es determinar de qué manera la gestión de cuentas por cobrar influye en la liquidez de la empresa Grupo Eléctrico Gonzales S.A.C., Lima, 2018. El tipo de investigación es aplicada, el enfoque es cuantitativo, su alcance es correlacional de diseño: no experimental-transversal. La población está conformada por 10 empleados pertenecientes a las áreas de Gerencia, Administración, Almacén, Ventas, Cobranzas, y Contabilidad, y la muestra es de tipo censal. Las técnicas de recolección de datos serán el Cuestionario y el Análisis documental, se aplicará los Estados Financieros y la Encuesta como instrumentos. Se concluye que la gestión de cuentas por cobrar influye en la liquidez de la empresa Grupo Eléctrico Gonzales S.A.C., pues el ratio de periodo promedio de cobranza nos indica que las cuentas por cobrar se convierten en efectivo en 71 días, debiendo convertirse en 30 días que es plazo máximo que se otorga al cliente para cancelar su deuda, respecto a la liquidez nos muestra el ratio de prueba defensiva que sus activos más líquidos no cubren en lo más mínimo sus obligaciones a corto plazo, indica que por cada sol de adeudo cuentan con 0.11 soles para asumirlo, lo que le conlleva a recurrir a financiamiento bancario.The objective of the investigation is to determine how the management of accounts receivable influences the liquidity of the company Grupo Eléctrico Gonzales SAC, Lima, 2018. The type of research is applied, the approach is quantitative, its scope is correlational design : nonexperimental-transversal. The population is made up of 10 employees belonging to the areas of Management, Administration, Warehouse, Sales, Collections, and Accounting, and the sample is of a census type. The data collection techniques will be the Questionnaire and the Documentary Analysis, the Financial Statements and the Survey will be applied as instruments. It is concluded that the management of accounts receivable influences the liquidity of the company Grupo Eléctrico Gonzales SAC, since the ratio of the average collection period indicates that the accounts receivable become cash in 71 days, and must become 30 days. It is the maximum term that is granted to the client to cancel their debt, regarding liquidity it shows us the defensive test ratio that their most liquid assets do not cover in the least their short-term obligations, indicates that for each debt due they have 0.11 soles to assume it, which leads him to resort to bank financing

Las afecciones del pericardio en el Kitab al-Taysir de Avenzoar (c. 1095-1162)

Avenzoar aparece como el primer descriptor de las inflamaciones del pericardio en la literatura historico-médica. De nuestro trabajo se desprende que, si bien Avenzoar elaboró un estudio propio de las enfermedades del pericardio, con una marcada orientación patológica, su marco epistemológico fue semejante al utilizado por autores que constituyeron la fuente de conocimiento para la medicina islámica, Galeno y Avicena. Hemos constatado que la consideración dada a Avenzoar parece haberse derivado de la carencia de datos anatomofisiológicos y de la pormenorizada descripción de las indicaciones y de los recursos terapéuticos que distinguen su estudio de los anteriores

Efficacy and Safety of Dry Powder Antibiotics: A Narrative Review

The use of inhaled antibiotics was initially almost exclusively confined to patients with cystic fibrosis (CF). However, it has been extended in recent decades to patients with non-CF bronchiectasis or chronic obstructive pulmonary disease who present with chronic bronchial infection by potentially pathogenic microorganisms. Inhaled antibiotics reach high concentrations in the area of infection, which enhances their effect and enables their long-term administration to defeat the most resistant infections, while minimizing possible adverse effects. New formulations of inhaled dry powder antibiotics have been developed, providing, among other advantages, faster preparation and administration of the drug, as well as avoiding the requirement to clean nebulization equipment. In this review, we analyze the advantages and disadvantages of the different types of devices that allow the inhalation of antibiotics, especially dry powder inhalers. We describe their general characteristics, the different inhalers on the market and the proper way to use them. We analyze the factors that influence the way in which the dry powder drug reaches the lower airways, as well as aspects of microbiological effectiveness and risks of resistance development. We review the scientific evidence on the use of colistin and tobramycin with this type of device, both in patients with CF and with non-CF bronchiectasis. Finally, we discuss the literature on the development of new dry powder antibiotics

Covid-19 control measures and its impact on seafarers’ mental health

The appearance of COVID-19 in maritime transport has been an exceptional challenge for all stakeholders in this sector, mainly for seafarers who have been caught between the need to keep supply chains operational and the limitations imposed by administrations to prevent the spread of the virus. With these objectives in mind, international institutions and organizations have developed a long series of regulations that have emerged in parallel with the measures established to control the pandemic. This article compiles the recommendations and regulations on health management established for this sector, as well as the implications of this entire process on fatigue and stress in seafarers.  Issues such as difficulties experienced in crew changes and repatriation, extended working hours, social isolation caused by mobility limitations in ports, limited medical equipment and services available, health care restrictions in some ports, the need to quarantine, and the possibility of being infected have been reported, among others, as causes of increased fatigue and stress among seafarers, as well as an upturn in anxiety, depression and other psychiatric disorders in this group. Thus, despite the efforts of the international maritime community to regulate the problematic areas related to the outbreak of the pandemic with the aim of keeping seafarers free of coronavirus and facilitating the continuity of maritime transport, its levels of fatigue and stress have increased notably, demonstrating that these efforts have neither been sufficient nor effective regulations have been developed that specifically take into account how COVID-19 and actions aimed at the continuity of maritime transport have affected and may continue to affect seafarers’ mental health.Peer Reviewe

Desarrollo morfosintáctico según el sexo, la edad y el tipo de gestión educativa en niños de 2 a 3 años de instituciones de educación inicial del distrito de San Juan de Lurigancho

Do you know if the morphosyntactic development is the same in children of different gender, age and school or differs according to these? In the process of language acquisition, there are a number of uncertainties that psycholinguistics, linguistics, psychology and education seek to clarify, in order to improve our knowledge about this situation. Therefore, this thesis tries to describe the morphosyntactic development of children from 2 to 3 years of age and their differences according to sex, age and type of educational management in the district of San Juan de Lurigancho, Lima - Peru. Next, the process, the results and the conclusion of the present investigation will be presented. For this, the Average Length of Morphea Statement (LME) was used as a measurement instrument, since it is an indicator of the morphosyntactic development of a child. In addition, a new proposal of morphosyntactic analysis is presented. In this sense, it was possible to reach the proposed objectives of checking, determining, describing, analyzing and comparing the morphosyntactic development of competent children of the Spanish language. Since the morphemes used in the sample were quantified, which were collected in different spontaneous situations. Likewise, the frequency of use of these morphemes was verified according to sex, age and type of educational management. And the descriptive - correlational method was used. The results will serve to identify linguistic alterations in morphosyntactic development and from this, to propose, in the future, work strategies to improve the performance of children from 2 to 3 years. Also, a morphosyntactic development pattern will be available to guide the planning of future interventions. Finally, we conclude that there are significant differences in morphosyntactic development according to age and type of schooling, but not with respect to sex.Tesi