Diversity and biotechnological potential of culturable bacteria from Brazilian mangrove sediment.

Mangrove ecosystems are environments subject to substantial degradation by anthropogenic activities. Its location, in coastal area, interfacing the continents and the oceans makes it substantially important in the prospection for biotechnological applications. In this study, we assessed the diversity of culturable bacteria present over the seasons at two depths (0-10 and 30-40 cm) in a mangrove sediment and in a transect area from the land to the sea. In total, 238 bacteria were isolated, characterized by Amplified Ribosomal DNA Restriction Analysis (ARDRA) and further identified, by Fatty Acid Methyl Esther (FAME-MIDI), into the orders of Vibrionales, Actinomycetales and Bacillales. Also the ability of the isolates in producing economically important enzymes (amylases, proteases, esterases and lipases) was evaluated and the order Vibrionales was the main enzymatic source.

Real-time Biosensor for the Assessment of Nanotoxicity and Cancer Electrotherapy

Knowledge of cell electronics has led to their integration to medicine either by physically interfacing electronic devices with biological systems or by using electronics for both detection and characterization of biological materials. In this dissertation, an electrical impedance sensor (EIS) was used to measure the electrode surface impedance changes from cell samples of human and environmental toxicity of nanoscale materials in 2D and 3D cell culture models. The impedimetric response of human lung fibroblasts and rainbow trout gill epithelial cells when exposed to various nanomaterials was tested to determine their kinetic effects towards the cells and to demonstrate the biosensor’s ability to monitor nanotoxicity in real-time. Further, the EIS allowed rapid, real-time and multi-sample analysis creating a versatile, noninvasive tool that is able to provide quantitative information with respect to alteration in cellular function. We then extended the application of the unique capabilities of the EIS to do real-time analysis of cancer cell response to externally applied alternating electric fields at different intermediate frequencies and low-intensity. Decreases in the growth profiles of the ovarian and breast cancer cells were observed with the application of 200 and 100 kHz, respectively, indicating specific inhibitory effects on dividing cells in culture in contrast to the non-cancerous HUVECs and mammary epithelial cells. We then sought to enhance the effects of the electric field by altering the cancer cell’s electronegative membrane properties with HER2 antibody functionalized nanoparticles. An Annexin V/EthD-III assay and zeta potential were performed to determine the cell death mechanism indicating apoptosis and a decrease in zeta potential with the incorporation of the nanoparticles. With more negatively charged HER2-AuNPs attached to the cancer cell membrane, the decrease in membrane potential would thus leave the cells more vulnerable to the detrimental effects of the applied electric field due to the decrease in surface charge. Therefore, by altering the cell membrane potential, one could possibly control the fate of the cell. This whole cell-based biosensor will enhance our understanding of the responsiveness of cancer cells to electric field therapy and demonstrate potential therapeutic opportunities for electric field therapy in the treatment of cancer.

Isolating the photovoltaic junction: atomic layer deposited TiO2-RuO2 alloy Schottky contacts for silicon photoanodes

We synthesized nanoscale TiO2-RuO2 alloys by atomic layer deposition (ALD) that possess a high work function and are highly conductive. As such, they function as good Schottky contacts to extract photogenerated holes from n-type silicon while simultaneously interfacing with water oxidation catalysts. The ratio of TiO2 to RuO2 can be precisely controlled by the number of ALD cycles for each precursor. Increasing the composition above 16% Ru sets the electronic conductivity and the metal work function. No significant Ohmic loss for hole transport is measured as film thickness increases from 3 to 45 nm for alloy compositions >= 16% Ru. Silicon photoanodes with a 2 nm SiO2 layer that are coated by these alloy Schottky contacts having compositions in the range of 13-46% Ru exhibit average photovoltages of 525 mV, with a maximum photovoltage of 570 mV achieved. Depositing TiO2-RuO2 alloys on nSi sets a high effective work function for the Schottky junction with the semiconductor substrate, thus generating a large photovoltage that is isolated from the properties of an overlying oxygen evolution catalyst or protection layer.

ORDENAMIENTO DEL TERRITORIO LOCAL ASISTIDO A TRAVES DE UN SISTEMA DE INFORMACIÓN GEOGRÁFICA.

El presente artículo muestra la aplicación de un Sistema de Información Geográfica (SIG) con una interfase con manejador de base de datos. El SIG utilizado es de modelo raster sin la capacidad de desarrollar una base de datos descriptiva. La aplicación desarrollada es conocida como Sistema de Información Geográfica para Gobiernos Locales (SIGGLO)y el área donde se implementó fue en el cantón de santo Domingo de la provincia de Heredia. En el apartado Los Planes de ordenamiento Territorial se discute sobre la utilidad que posee este tipo de instrumentos, que regulan el ordenamiento a nivel local y en forma paralela los autores presentan sus inquietudes del porqué los planes reguladores no han tenido el éxito deseado. Posteriormente, se presenta la visión de los autores sobre Los Planes de ordenamiento Manuales vs. Automatizados, el cual permite presentar las ventajas y desventajas que poseen los SiGs para implementar un Plan de Ordenamiento a través de esta tecnología. Seguidamente se presenta en detalle la experiencia obtenida con el SIGGLO, donde se explica la utilización del SIG y de un paquete de digitalización para combinar luego ambos con un manejador de bases de datos. Por último, se presentan una serie de restricciones que tiene el SIGGLO, también las recomendaciones que se deberían considerar al implementar un nuevo proyecto bajo la metodología del SIGGLO. ABSTRACTThe present article presents an application of a data base management system interfacing with a Geographical Information System (GIS). The utilized GIS for the project is a raster based system without the ability to develop a descriptive data base. This system is called Geographical Information System for Local Governments (SIGGLO) and was implemented in the canton of Santo Domingo, Costa Rica. It is mentioned in Territorial Organization Plans the utility that GIS systems have in regulating organization on a local level. In parallel form, the authors present their doubts of why these regulatory plans have not had the desired success. Afterwards, the authors present their vision of an Organization Plan for Manual and Automated functions which permit the presentation of the advantages and disadvantages that contain GIS in order to implement a Organization Plan with these technologies. Following this is a detailed presentation of the experience obtained with SIGGLO and where it is explained the utility of the GIS and of a digitizing software package which was later combined in the data base management system. Finally, a series of restrictions is presented that SIGGLO has which also contains details of recommendations that should be considered upon implementing a new project under the SIGGLO methodology.

La ricerca archeologica e il regime dei ritrovamenti e delle scoperte nel sottosuolo e nei fondali marini. La disciplina del Codice tra attuazione e prospettive di riforma anche alla luce di un'analisi comparativa con l'esperienza francese e spagnola.

Il lavoro è volto all’approfondimento, anche in chiave comparatistica, della vigente normativa riguardante la tutela e la valorizzazione dei beni archeologici. Nell’ambito della disciplina predisposta nell’ordinamento italiano si sono prese le mosse dal regime delle scoperte e dei ritrovamenti, per passare successivamente all’approfondimento della tutela approntata nella legislazione nazionale anche con riferimento alle limitazioni alla libera disponibilità e circolazione. Una particolare attenzione è stata dedicata alla tutela del territorio in cui i beni archeologici sono inseriti e quindi alla tutela indiretta, ai vincoli ope legis e alla pianificazione paesaggistica, mentre una specifica trattazione ha riguardato il regime dell’archeologia preventiva e la valorizzazione e fruizione di aree e parchi archeologici nel reciproco interfacciarsi delle legislazioni regionali e delle linee guida emanate con il d.m. MiBAC 18 aprile 2012. Un’indagine articolata ha avuto per oggetto la tutela del patrimonio archeologico subacqueo e in particolare la Convenzione dell’UNESCO adottata a Parigi nel 2001, nonché la tutela sovranazionale dei beni culturali, con riferimento alla disciplina dell’Unione europea e a quella della Convenzione europea per la protezione del patrimonio archeologico del 16 gennaio 1992 e della Convenzione UNIDROIT del 24 giugno 1995 sui beni culturali rubati o esportati illegalmente. Hanno infine fatto seguito due specifiche indagini sulla tutela del patrimonio archeologico in Spagna e in Francia. Quanto alla prima si è esaminato l’attuale quadro costituzionale in cui si inserisce la tutela del patrimonio culturale con particolare attenzione alle disposizioni della Ley 16/1985 del 25 giugno 1985 e alla legislazione delle Comunidades autónomas. Per quanto riguarda la seconda una particolare attenzione è stata dedicata alla Legge 27 settembre 1941 che ha introdotto in Francia la prima disciplina organica relativa agli scavi e ai ritrovamenti archeologici. Nel quadro normativo vigente un’analisi particolareggiata è stata dedicata al Code du Patrimoine, il cui quinto libro è interamente dedicato all’archeologia.

Functional engineering of hybrid heterostructures for application in electronic, optical and optoelectronic nanostructured devices

Interfacing materials with different intrinsic chemical-physical characteristics allows for the generation of a new system with multifunctional features. Here, this original concept is implemented for tailoring the functional properties of bi-dimensional black phosphorus (2D bP or phosphorene) and organic light-emitting transistors (OLETs). Phosphorene is highly reactive under atmospheric conditions and its small-area/lab-scale deposition techniques have hampered the introduction of this material in real-world applications so far. The protection of 2D bP against the oxygen by means of functionalization with alkane molecules and pyrene derivatives, showed long-term stability with respect to the bare 2D bP by avoiding remarkable oxidation up to 6 months, paving the way towards ultra-sensitive oxygen chemo-sensors. A new approach of deposition-precipitation heterogeneous reaction was developed to decorate 2D bP with Au nanoparticles (NP)s, obtaining a “stabilizer-free” that may broaden the possible applications of the 2D bP/Au NPs interface in catalysis and biodiagnostics. Finally, 2D bP was deposited by electrospray technique, obtaining oxidized-phosphorous flakes as wide as hundreds of µm2 and providing for the first time a phosphorous-based bidimensional system responsive to electromechanical stimuli. The second part of the thesis focuses on the study of organic heterostructures in ambipolar OLET devices, intriguing optoelectronic devices that couple the micro-scaled light-emission with electrical switching. Initially, an ambipolar single-layer OLET based on a multifunctional organic semiconductor, is presented. The bias-depending light-emission shifted within the transistor channel, as expected in well-balanced ambipolar OLETs. However, the emitted optical power of the single layer-based device was unsatisfactory. To improve optoelectronic performance of the device, a multilayer organic architecture based on hole-transporting semiconductor, emissive donor-acceptor blend and electron-transporting semiconductor was optimized. We showed that the introduction of a suitable electron-injecting layer at the interface between the electron-transporting and light-emission layers may enable a ≈ 2× improvement of efficiency at reduced applied bias.