Gold nanoparticle to antibody conjugates for diagnosis applications: molecular interactions and immunoassay development

Thesis for the Master degree in Structural and Functional BiochemistryBionanotechnology is an area of rapidly increasing research interest, whose development can potentially improve many fields of our society by providing several advances in biomedical, energy and environment research fields. The present work includes both applied and basic research on bionanoconjugates of gold nanoparticles (AuNP) with antibodies (Ab) referred to as AuNP@Ab. The two main themes of research are: i) development of a fluorescence immunoassay for malaria diagnosis, using a sensing methodology involving the competitive binding between a fluorophore-labeled antigen (CyAg) and the unlabeled antigen (Ag) to the AuNP@Ab conjugates. The Ag is a new biomarker of malaria infection, the heat shock protein 70 from Plasmodium falciparum (PfHsp70). ii) physico-chemical characterization of the interaction between the Ag and the AuNP@Ab using Fluorescence, Differential Centrifugal Sedimentation (DCS), and Agarose Gel Electrophoresis(AGE), intended at understanding the nature of the binding, particularly its specificity and the influence of nonspecific protein competitors. The immunoassay for malaria diagnosis was successfully established using fluorescence detection for AuNPs of different diameters (15 and 30 nm) and using AGE detection for 30 nm-AuNPs. The AuNP@Ab bionanoconjugates exhibited a specific response to the target Ag, with little, or none, non-specific binding when purified transferrin (Trf) is used. Non-specific binding of proteins from plasma was nevertheless detected. Ag binding to AuNP@Ab was assessed in competitive conditions both with plasma and with Trf. Trf inhibited the Ag binding, while plasma inhibited the Ag binding as accessed by DCS but the same conclusion could not be made for fluorescence due to the large background signal caused by plasma unspecific binding

La naturaleza en la fotografía de Virxilio Viéitez

The present essay suggests an approach to the archive of Galician rural photographer Virxilio Viéitez (1930-2008) from the theoretical view of ecocriticism, with the aim of delve into the role of nature in his photographs. The analysis is organized in three points; the first, representation of landscape, poses a characterization of the unit landscape of the region in which the photographer performed his work, Terra de Montes (Pontevedra), and studies the role that humans play in it. The second, animals, offers a proposal of classification for the species that appear in the archive according to their relation to human being and introduces the notion of “change”, essential in the third point, the image of the rural, which defines the vision of the village the archive gives and its chronological variations. In the conclusion the previous points are brought to the current reality of rural Galicia with the objective of inspiring a response from rural activism to the process of “urban colonization” of the rural area that is demonstrated throughout the work.El presente ensayo propone una aproximación al archivo del fotógrafo rural gallego Virxilio Viéitez (1930-2008) desde la perspectiva teórica de la ecocrítica, con el fin de profundizar en el papel de la naturaleza en sus fotografías. El análisis se organiza en tres núcleos; el primero, la representación del paisaje, plantea una caracterización del paisaje unitario de la comarca en la que el fotógrafo llevó a cabo su obra, Terra de Montes (Pontevedra), e indaga en el rol que juega el humano dentro de ella. El segundo, los animales, ofrece una propuesta de clasificación para las especies que aparecen en el archivo en función de su relación con el ser humano e introduce la noción de “cambio”, esencial en el tercer núcleo, la imagen del rural, que define la visión de la aldea que transmite el archivo y sus variaciones cronológicas. En la conclusión se aplica lo estudiado a la realidad actual del rural gallego con el objetivo de inspirar una respuesta del activismo ruralista al proceso de “colonización urbana” del ámbito rural que se viene evidenciando a lo largo del trabajo

Estrategias de atribución automática de autoría aplicadas al teatro de Tirso de Molina

Traballo de Fin de Grao en Lingua e Literatura Españolas. Curso 2018-2019La abundante producción dramática de Tirso de Malina (1579-1648) cuenta con varios casos de autoría dudosa que tradicionalmente se han venido atribuyendo al mercedario madrileño sin una base documental sólida. Entre ellos destaca la célebre obra El burlador de Sevilla, fundadora del mito de Don Juan, que un cierto sector de la crítica atribuye al dramaturgo Andrés de Claramonte (c. 1560·1626) y que además presenta otros problemas ecdóticos añadidos a raíz de la aparición de una versión alternativa del texto publicada bajo el título de Tan largo me lo fiáis. Ambos fenómenos evidencian el intrincado proceso de transmisión textual de las comedias del Siglo de Oro, germen de multitud de discusiones entre la crítica. El propósito de este trabajo es configurar un corpus de comedias con el fin de realizar análisis comparativos de estilo a través de diferentes herramientas informáticas basadas en técnicas cuantitativas y estadísticas, de manera que se puedan extraer resultados numéricos que, interpretados en su contexto, sirvan como indicios para reforzar alguna de las múltiples posturas defendidas en este controvertido debat

The regulation of transcriptional repression in hypoxia

A sufficient supply molecular oxygen is essential for the maintenance of physiologic metabolism and bioenergetic homeostasis for most metazoans. For this reason, mechanisms have evolved for eukaryotic cells to adapt to conditions where oxygen demand exceeds supply (hypoxia). These mechanisms rely on the modification of pre-existing proteins, translational arrest and transcriptional changes. The hypoxia inducible factor (HIF; a master regulator of gene induction in response to hypoxia) is responsible for the majority of induced gene expression in hypoxia. However, much less is known about the mechanism(s) responsible for gene repression, an essential part of the adaptive transcriptional response. Hypoxia-induced gene repression leads to a reduction in energy demanding processes and the redirection of limited energetic resources to essential housekeeping functions. Recent developments have underscored the importance of transcriptional repressors in cellular adaptation to hypoxia. To date, at least ten distinct transcriptional repressors have been reported to demonstrate sensitivity to hypoxia. Central among these is the Repressor Element-1 Silencing Transcription factor (REST), which regulates over 200 genes. In this review, written to honor the memory and outstanding scientific legacy of Lorenz Poellinger, we provide an overview of our existing knowledge with respect to transcriptional repressors and their target genes in hypoxia

Optimização do desmonte numa mina a céu aberto com aplicação de air decks

Tese de mestrado. Engenharia de Minas de Geo-Ambiente. Universidade do Porto. Faculdade de Engenharia. 201

Does 3D Ultrasound Enhance the Diagnosis of Bladder Tumours in Patients with Haematuria?

Purpose. Bladder cancer is a frequent cause of haematuria in elderly patients, and bladder ultrasound (US) is a valuable tool in diagnosing these malignancies. We examined the accuracy of 3D bladder US in diagnosing bladder tumors in patients with haematuria. Patients and Methods. Twenty-one patients observed in the emergency department for haematuria underwent a kidney and bladder US. Patients with normal or uncertain bladder US findings underwent a 3D US and a cystoscopy. Results. In 5 (23.8%) patients, the 3D US detected bladder tumours not seen in 2D US. All these patients were found to have bladder tumours on cystoscopy. Another 5 (23.8%) patients with uncertain findings on 2D US had normal 3D US and cystoscopy. 3D US showed a sensitivity of 83.3% and a specificity of 100% with a positive predicted value and negative predictive values of 100% and 93.8%, respectively. Conclusion. 3D US was more sensitive than 2D US in diagnosing bladder tumours in patients with haematuria

Afadin Downregulation by Helicobacter pylori Induces Epithelial to Mesenchymal Transition in Gastric Cells

Afadin is a cytoplasmic protein of the adherens junctions, which regulates the formation and stabilization of both the adherens and the tight junctions. Aberrant expression of Afadin has been shown in cancer and its loss has been associated with epithelial-to-mesenchymal transition (EMT). EMT is characterized by the change from an epithelial to a mesenchymal phenotype, with modifications on the expression of adhesion molecules and acquisition of a migratory and invasive cell behavior. While it is known that Helicobacter pylori disrupts the tight and the adherens junctions and induces EMT, the effect of the bacteria on Afadin is still unknown. The aim of this study was to disclose the effect of H. pylori on Afadin and its impact in the induction of an EMT phenotype in gastric cells. Using two different cell lines, we observed that H. pylori infection decreased Afadin protein levels, independently of CagA, T4SS, and VacA virulence factors. H. pylori infection of cell lines recapitulated several EMT features, displacing and downregulating multiple proteins from cell–cell junctions, and increasing the expression of ZEB1, Vimentin, Slug, N-cadherin, and Snail. Silencing of Afadin by RNAi promoted delocalization of junctional proteins from the cell–cell contacts, increased paracellular permeability, and decreased transepithelial electrical resistance, all compatible with impaired junctional integrity. Afadin silencing also led to increased expression of the EMT marker Snail, and to the formation of actin stress fibers, together with increased cell motility and invasion. Finally, and in line with our in vitro data, the gastric mucosa of individuals infected with H. pylori showed decrease/loss of Afadin membrane staining at cell–cell contacts significantly more frequently than uninfected individuals. In conclusion, Afadin is downregulated by H. pylori infection in vitro and in vivo, and its downregulation leads to the emergence of EMT and to the acquisition of an aggressive phenotype in gastric cells, which can contribute to gastric carcinogenesis