Regulation of gene expression by the cAMP-Crp system in the soil bacterium Pseudomonas putida

Tesis doctoral inédita, leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 22-06-201

Detección del virus del mosaico de Cymbidium y el virus de la mancha anillada de Odontoglossum mediante TD/RT-PCR en orquídeas cultivadas en vivero

Proyecto de Graduación (Bachillerato en Ingeniería en Biotecnología). Instituto Tecnológico de Costa Rica, Escuela de Biología, 2006.El virus del mosaico del Cymbidium (CymMV) y el virus de la mancha anillada de Odontoglossum (ORSV) son los dos virus más problemáticos en el cultivo de orquídeas. Mediante la estandarización de un protocolo de Touchdown/RT-PCR utilizando oligonucleótidos degenerados se logró detectar simultáneamente la infección de ambos virus en algunas muestras de orquídeas de diferentes géneros procedentes de dos viveros de la provincia de Alajuela. En ambos invernaderos se detectó la contaminación viral en el 50% de las plantas evaluadas, siendo la infección por el CymMV más frecuente que el ORSV. Solamente el 5% del total de plantas se encontraron con infección mixta. Las plantas infectadas presentaban síntomas (80%) o podían ser asintomáticas (20%), siendo estas últimas una fuente potencial de inóculo para virus que son de transmisión mecánica. Al realizar un estudio comparativo entre el ELISA y la técnica estandarizada para la detección de ambos virus se determinó que la metodología de TD/RT-PCR permite una detección simultánea del CymMV y el ORSV en un menor tiempo, con mayor sencillez, sensibilidad y un menor costo que esta técnica serológica

Fluorescence emission analysis of photodynamic therapy photosensitizer as a monitoring biomarker

Photodynamic Therapy is a selective optical tumor destruction technique with practically no secondary effects. Monitoring by fluorescence photosensitizer emission is essential for an adequate treatment dosimetry, which avoids recurrence.This work has been partially supported by the project “New active phases in transition metals and rare earth nano-oxides stabilized at high pressure” (MAT2015-69508-P) of the Spanish Ministry of Economy and Competitiveness, cofunded by FEDER funds, and by the San Cándido Foundation

Measuring the symbiotic performance of single entities within networks using an LCA approach

Altres ajuts: acords transformatius de la UABUnidad de excelencia María de Maeztu CEX2019-000940-MThis research was funded by Consejo Nacional de Investigaciones Científicas y Técnicas-CONICET, Argentina.This paper introduces the Symbiotic Performance Indicator, a novel indicator aiming to quantify the environmental benefits generated by by-product exchanges in an industrial symbiosis network. Despite the significant advancements in assessing industrial symbiosis, the lack of indicators for individual entities involved in by-product exchanges hinders a comprehensive understanding of its environmental benefits. This indicator accounts for resource use and greenhouse gas emissions using a life cycle perspective. The resource use is measured using the Cumulative Exergy Extraction from the Natural Environment method, while greenhouse gas emissions are evaluated using the IPCC 2013 Global Warming Potential (100a) method. The use of this indicator is illustrated in a real case study where plastic waste is exchanged among three entities in Mendoza (Argentina). The overall results show that resource use and greenhouse gas emissions can be reduced by 19% and 15%, respectively. Full and partial allocation methods are proposed within the formulation of the Symbiotic Performance Indicator. The indicator results show that the exchange of materials may seem less attractive when using full allocation methods, as one entity gets 100% of the benefits from the by-product exchange compared to the other. Partial allocations make the by-product exchange convenient for both entities which may encourage collaboration. In conclusion, the proposed indicator helps account more precisely for individual environmental benefits behind by-product exchanges, and thus enables better decision-making to set up an industrial symbiosis network

Optical characterization of tissue-simulating phantoms with microparticles by Digital Image Plane Holography

Digital Image Plane Holography (DIPH) is a non-invasive optical technique which is able to recover the whole object wave. An object is illuminated and the diffused backscattered light is carried to a digital sensor by using a lens, where it interferes with a divergent reference wave with its origin in the lens aperture plane. Selecting each aperture image in the Fourier plane, the amplitude and the phase of the object beam are obtained. If two holograms are recorded at different times, after a small displacement, the reconstructed intensity distributions can be taken as a speckle field, while the phase difference distribution can be analyzed by an interferometric approach. In this work scattering media are investigated by using digital holography. The aim of this paper is to determine the viability of the technique to characterized optical properties of the sample. Different scattering media are modeled with different scattering properties. Each model generates a speckle pattern with different statistical properties (size, contrast, intensity). Both the visibility of the interferometric fringes and the properties of speckle pattern are related with optical properties of the media such as absorption and scattering coefficient. The ability to measure these properties makes the technique a promising method for biomedical applications.This work has been partially supported by the project “New active phases in transition metals and rare earth nano-oxides stabilized at high pressure” (MAT2015-69508-P) of the Spanish Ministry of Economy and Competitiveness, cofunded by FEDER funds, and by the San Cándido Foundation

Analysis of nanoparticles optical propagation influence in biological tissue simulating phantoms

The applications of nanoparticles in optical techniques of diagnosis and treatment of biological tissues are increasing. Image contrast can be improved in diagnostic approaches such as fluorescence, spectroscopy or optical coherence tomography. The therapeutic effect can be increased if nanoparticles are previously incorporated in the biological tissue. This is the case in thermotherapy, or in Photodynamic Therapy. All these applications take advantage of specific properties of the nanoparticles involved, either optical up- or down-conversion, thermal confinement or the ability to act as a drug-carrier. Although many biomedical applications that involve nanoparticles are being proposed and tested, there is a need to take into account the influence of those nanoparticles on optical radiation propagation. The previously mentioned optical treatment and diagnosis techniques assume a particular optical propagation pattern, which is altered by the addition of nanoparticles. This change depends on the nanoparticle material, shape, size and concentration, among other parameters. In order to try to quantify these changes, in this work several phantoms that include different nanoparticles are analyzed, in order to estimate the influence of nanoparticles in optical propagation. A theoretical model of optical propagation, which takes into account the absorption and scattering changes in the medium, is also considered. Nanoparticles of different sizes from 40 nm to 1µm are analyzed. Nanoparticle materials of interest in biomedical applications are employed. The results are relevant in diagnosis interpretation of images and treatment outcome evaluation when nanoparticles are present.This work has been partially supported by the project “New active phases in transition metals and rare earth nano-oxides stabilized at high pressure” (MAT2015-69508-P) of the Spanish Ministry of Economy and Competitiveness, cofunded by FEDER funds, and by the San Cándido Foundation

Evaluación ambiental de alternativas para el agregado de valor a subproductos de aserraderos en Mendoza

La industria de la madera en Mendoza se encuentra relegada en relación a otros sectores industriales y tiene baja productividad, generando un elevado porcentaje de residuos o subproductos. En general, estos son ofrecidos en el mercado, pero la dificultad para el agregado de valor conduce al desaprovechamiento de oportunidades de mercado y, en ocasiones, a soluciones perjudiciales para el ambiente. Por tanto, el objetivo de este trabajo fue contribuir al agregado de valor a los subproductos en un aserradero tipo de la Provincia de Mendoza. Para ello, se propusieron opciones para el reprocesamiento de los subproductos, y se compararon considerando los impactos sobre el cambio climático y el nivel de circularidad material alcanzado. Se utilizó la metodología del Análisis de Ciclo de Vida y se calculó el Indicador de Circularidad Material a partir de datos suministrados por propietarios de aserraderos. Los resultados mostraron que la producción de chips de madera y la venta del aserrín para la producción de ladrillos provocan el menor impacto sobre el cambio climático por cada unidad de beneficio económico generado. Asimismo, esta opción de procesamiento presenta un buen desempeño respecto al nivel de circularidad alcanzado.The wood industry in Mendoza is relegated to other industrial sectors, and it has low productivity. Thus, it generates a high percentage of wood residues or by-products that, in general, are offered in the market. However, the difficulty in adding value leads to the waste of market opportunities and, sometimes, to harmful solutions to the environment. Therefore, the aim of this work was to contribute to the value addition of by-products from wood sawing in a typical sawmill in Mendoza. For that purpose, options for the reprocessing of by-products were proposed, and they were compared considering impacts on climate change and the degree of material circularity achieved. Life Cycle Assessment methodology was used, and Material Circularity Indicator was calculated from data provided by sawmills owners. The results showed that the production of wood chips and the sale of sawdust for bricks production cause the lowest impact on climate change for each unit of economic benefit generated. In addition, this processing option presents a good performance regarding the degree of circularity achieved.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Synergistic Antifungal Study of PEGylated Graphene Oxides and Copper Nanoparticles against Candida albicans

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).The coupling reactions of polyethylene glycol (PEG) with two different nano-carbonaceous materials, graphene oxide (GO) and expanded graphene oxide (EGO), were achieved by amide bond formations. These reactions yielded PEGylated graphene oxides, GO-PEG and EGO-PEG. Whilst presence of the newly formed amide links (NH-CO) were confirmed by FTIR stretches observed at 1732 cm−1 and 1712 cm−1, the associated Raman D- and G-bands resonated at 1311/1318 cm−1 and 1584/1595 cm−1 had shown the carbonaceous structures in both PEGylated products remain unchanged. Whilst SEM images revealed the nano-sheet structures in all the GO derivatives (GO/EGO and GO-PEG/EGO-PEG), TEM images clearly showed the nano-structures of both GO-PEG and EGO-PEG had undergone significant morphological changes from their starting materials after the PEGylated processes. The successful PEGylations were also indicated by the change of pH values measured in the starting GO/EGO (pH 2.6–3.3) and the PEGylated GO-PEG/EGO-PEG (pH 6.6–6.9) products. Initial antifungal activities of selective metallic nanomaterials (ZnO and Cu) and the four GO derivatives were screened against Candida albicans using the in vitro cut-well method. Whilst the haemocytometer count indicated GO-PEG and copper nanoparticles (CuNPs) exhibited the best antifungal effects, the corresponding SEM images showed C. albicans had, respectively, undergone extensive shrinkage and porosity deformations. Synergistic antifungal effects all GO derivatives in various ratio of CuNPs combinations were determined by assessing C. albicans viabilities using broth dilution assays. The best synergistic effects were observed when a 30:70 ratio of GO/GO-PEG combined with CuNPs, where MIC50 185–225 μm/mL were recorded. Moreover, the decreased antifungal activities observed in EGO and EGO-PEG may be explained by their poor colloidal stability with increasing nanoparticle concentrations.Peer reviewe

Standardization of inducer-activated broad host range expression modules: debugging and refactoring an alkane-responsive AlkS/PalkB device

Although inducible heterologous expression systems have been available since the birth of recombinant DNA technology, the diversity of genetic devices and their coming together in the corresponding vectors often result in a lack of reproducibility and interoperability. In an effort to increase the predictability of expression of genes of interest in a variety of possible bacterial hosts, we propose a composition standard for debugging and reassembling all regulatory parts that participate in the performance of such devices. As a case study, we addressed the n-octane and dicyclopropyl ketone-inducible PalkB promoter of the alkane biodegradation pOCT plasmid of Pseudomonas putida. The standardized expression module included an edited alkS transcription factor divergently expressed and separated from PalkB by a synthetic buffer segment. The DNA sequence of the alkS gene was modified to alleviate the catabolite repression exerted by several carbon and nitrogen sources through the Crc/Hfq complex of some hosts. The PalkB promoter and the alkS variants were then formatted as Standard European Vector Architecture cargoes, and their activity in P. putida was quantified with fluorescent and luminescent reporters. Despite considerable editing of the DNA sequences involved, the thereby refactored module basically kept the functioning parameters of the original configuration. The same qualities were inspected when the system was passed to Escherichia coli and Pseudomonas aeruginosa. We argue that the application of the compositional standard thereby implemented in the AlkS/PalkB module to other promoter/regulator pairs will enable more complex genetic programming in non-model bacteria.MADONNA H2020-FET OPEN-RIA-2017-1-766975BioRoboost H2020-NMBP-BIO-CSA 2018-820699SynBio4Flav H2020-NMBP-TR-IND/H2020-NMBP BIO-2018-814650MIX-UP H2020-BIO-CN-2019-87029

A Reassessment of the Kinematics of PV Cephei Based on Accurate Proper Motion Measurements

We present two Very Large Array observations of the pre-main-sequence star PV Cephei, taken with a separation of 10.5 years. These data show that the proper motions of this star are $\mu_{\alpha} = +10.9 \pm 3.0 \ mas \ yr^{-1}$; $\mu_{\delta} +0.2 \pm 1.8 \ mas \ yr^{-1}$, very similar to those – previously known – of HD 200775, the B2Ve star that dominates the illumination of the nearby reflection nebula NGC 7023. This result suggests that PV Cephei is not a rapidly moving run-away star as suggested by previous studies. The large velocity of PV Cephei had been inferred from the systematic eastward displacement of the bisectors of successive pairs of Herbig Haro knots along its flow. These systematic shifts might instead result from an intrinsic dissymmetry in the ejection mechanisms, or from an asymmetric distribution of the circumstellar material.Astronom