Band structures of periodic porphyrin nanostructures

Recent progress in the synthesis of π-conjugated porphyrin arrays of different shapes and dimensionalities motivates us to examine the band structures of infinite (periodic) porphyrin nanostructures. We use screened hybrid density functional theory simulations and Wannier function interpolation to obtain accurate band structures of linear chains, 2D nanosheets and nanotubes made of zinc porphyrins. Porphyrin units are connected by butadiyne (C4) or ethyne (C2) linkers, or “fused” (C0), i.e. with no linker. The electronic properties exhibit strong variations with the number of linking carbon atoms (C0/C2/C4). For example, all C0 nanostructures exhibit gapless or metallic band structures, whereas band gaps open for the C2 or C4 structures. The reciprocal space point at which the gaps are observed also show fluctuations with the length of the linkers. We discuss the evolution of the electronic structure of finite porphyrin tubes, made of a few stacked six-porphyrin rings, towards the behavior of the infinite nanotube. Our results suggest approaches for engineering porphyrin-based nanostructures to achieve target electronic properties

Evaluación de la plataforma de Tecnologías de Información y Comunicación (TICS) en el sistema semipresencial de educación a distancia

El siguiente proyecto está realizado con la finalidad que permita realizar la evaluación de las plataformas tecnológicas de información y comunicación para el diseño de un instructivo didáctico para educación virtual, puesto que su objetivo principal tiene que ver con el desarrollo y aplicación de la tecnología, adoptará rápidamente modelos educativos muy tecnificados como lo es la educación a distancia basada en ambientes virtuales, así como determinar y diagnosticar la trascendencia de los recursos tecnológicos en el Departamento Semipresencial de Educación a Distancia, aplicando instrumentos de investigación para potenciar los procesos educativos y la calidad del sistema de Educación a Distancia. Por esto se hace necesario implementar un proceso de investigación y evaluación para detectar a profundidad las causas e incidencias en los procesos administrativos, académicos y tecnológicos del centro. La importancia de la investigación y evaluación nos proporcionará los elementos precisos para implementar el instructivo didáctico para educación virtual

Potential Energy of Plant Biomass: Banana, Coconut, Cacao and Corn

In this document, a study was carried out on the energy potential of plant biomass in the Portoviejo canton, since climate change is not a utopia, but the reality. Throughout this study, an overview of the capacity in biomass at the national, provincial and cantonal level (Portoviejo) was presented, a study on the culture of banana, cocoa, coconut, and corn was made since it is important to know if the canton can respond to the biomass demand of the selected plants. Then the socio-economic and environmental impacts were analyzed in a general way

Emerging properties from mechanical tethering within a post-synthetically functionalised catenane scaffold

Maintaining close spatial proximity of functional moieties within molecular systems can result in fascinating emergent properties. Whilst much work has been done on covalent tethering of functional units for myriad applications, investigations into mechanically linked systems are relatively rare. Formation of the mechanical bond is usually the final step in the synthesis of interlocked molecules, placing limits on the throughput of functionalised architectures. Herein we present the synthesis of a bis-azide [2]catenane scaffold that can be post-synthetically modified using CuAAC ‘click’ chemistry. In this manner we have been able to access functionalised catenanes from a common precursor and study the properties of electrochemically active, emissive and photodimerisable units within the mechanically interlocked system in comparison to non-interlocked analogues. Our data demonstrates that the greater (co-)conformational flexibility that can be obtained with mechanically interlocked systems compared to traditional covalent tethers paves the way for developing new functional molecules with exciting properties

A practical approach for the compassionate use of convalescent plasma in patients with severe COVID-19 in developing countries

The COVID-19 pandemic has affected 187 countries, representing a global public health problem. The increasing number of critically ill patients and deaths have fueled a desperate search for treatments that can halt the course of the disease. Currently, there are several experimental therapies with demonstrated in vitro activity against COVID-19 used in clinical practice, including hydroxychloroquine, remdesivir, interleukin-6 pathway inhibitors, and convalescent plasma; however, to date no agent has proven efficacy against COVID-19. In the case of convalescent plasma, this therapy consists in obtaining neutralizing antibodies from previously infected individuals by plasmapheresis and administering them to patients with severe disease. Recently, the use of convalescent plasma has shown promising results in preliminary studies, with case series reporting a decrease in temperature, and viral load, as well as improvement in clinical parameters among patients receiving this treatment. However, there are still unmet needs regarding the safety profile, tolerability, dosage, and timing this therapy should be given. Based on this, the objective of our study was to develop and propose a practical approach for the compassionate use of convalescent plasma for the treatment of patients with severe COVID-19, given the constrains and limitations of developing countries. We encourage health professionals in developing countries to use the current evidence and approaches to experimental treatments for patients with COVID-19, adapting them to their conditions, and always based on a thorough risk-benefit evaluation for each patient, and whenever possible to design and promote the much needed research in this field

Genitourinary Neuroendocrine Neoplasms

Neuroendocrine neoplasms (NENs) of the genitourinary tract are uncommon, but the pathologist has to be prepared to recognize them and to assess the morphophenotypic factors that can drive their treatment and prognosis. NENs have been described in the kidney, urinary bladder, prostate, testes, uterine cervix, uterine corpus, and ovaries. The clinico-pathological features and the nomenclature of these neoplasms may vary from site to site. This chapter systematically reviews the spectrum of genitourinary NEN within the context of a unitary vision of the diagnostic criteria and classification, paralleling the scheme recently proposed by the World Health Organization and the International Agency for Research on Cancer (IARC)