21 research outputs found
Energetic study of ultrasonic wettability enhancement
[EN]Many industrial and biological interfacial processes, such as welding and breathing depend directly on wettability and surface tension phenomena. The most common methods to control the wettability are based on modifying the properties of the fluid or the substrate. The present work focuses on the use of high-frequency acoustic waves (ultrasound) for the same purpose. It is well known that ultrasound can effectively clean a surface by acoustic cavitation, hence ultrasonic cleaning technology. Besides the cleaning process itself, many authors have observed an important wettability enhancement when liquids are exposed to low and high (ultrasonic) frequency vibration. Ultrasound goes one step further as it can instantly adjust the contact angle by tuning the vibration amplitude, but there is still a lack of comprehension about the physical principles that explain this phenomenon. To shed light on it, a thermodynamic model describing how ultrasound decreases the contact angle in a three-phase wetting system has been developed. Moreover, an analytical and experimental research has been carried out in order to demonstrate that ultrasound is an important competitor to surfactants in terms of energy efficiency and environmental friendliness.The projects leading to this research have received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement N° 654479 WASCOP and N°792103 SOLWARIS
Non-Immersion Ultrasonic Cleaning: An Efficient Green Process for Large Surfaces with Low Water Consumption
Ultrasonic cleaning is a developed and widespread technology used in the cleaning industry. The key to its success over other cleaning methods lies in its capacity to penetrate seemingly inaccessible, hard-to-reach corners, cleaning them successfully. However, its major drawback is the need to immerse the product into a tank, making it impossible to work with large or anchored elements. With the aim of revealing the scope of the technology, this paper will attempt to describe a more innovative approach to cleaning large area surfaces (walls, floors, façades, etc.) which involves applying ultrasonic cavitation onto a thin film of water, which is then deposited onto a dirty surface. Ultrasonic cleaning is an example of the proliferation of green technology, requiring 15 times less water and 115 times less power than conventional high-pressurized waterjet cleaning mechanisms. This paper will account for the physical phenomena that govern this new cleaning mechanism and the competition it poses towards more conventional pressurized waterjet technology. Being easy to use as a measure of success, specular surface cleaning has been selected to measure the degree of cleanliness (reflectance) as a function of the process’s parameters. A design of experiments has been developed in line with the main process parameters: amplitude, gap, and sweeping speed. Regression models have also been used to interpret the results for different degrees of soiling. The work concludes with the finding that the proposed new cleaning technology and process can reach up to 98% total cleanliness, without the use of any chemical product and with very low water and power consumption.This research was funded by European Union’s Horizon 2020 research and innovation programme under grant agreement Nº 654479 WASCOP and Nº 792103 SOLWAR
Precariedad laboral, activismo y ciberacoso. Reflexiones sobre cómo participamos y nos posicionamos las mujeres en contextos de inseguridad social
In this special issue, we reflect on women's precarious situation in Chile and the world, which increased after forced confinement during the pandemic COVID19. In the face of these contexts of social insecurity, we have developed alternative mechanisms of manifestation and resistance through cyber activism. Threats to women's autonomy never disappear entirely, and this requires us to review the institutional frameworks that allow such setbacks when conservative or extreme right-wing groups take power.En este foro reflexionamos sobre la situación de precariedad a la que nos enfrentamos las mujeres en Chile y en el mundo; la cual se vió acrecentada luego de los confinamientos forzados durante la pandemia por COVID 19. Frente a dichos contextos de inseguridad social, hemos desarrollado mecanismos alternativos de manifestación y resistencia a través del ciberactivismo. Las amenazas frente a la autonomía de las mujeres nunca desaparecen del todo y eso requiere que revisemos los marcos institucionales que permiten tales retrocesos cuando asumen el poder grupos conservadores o de extrema derecha
Precariedad laboral, activismo y ciberacoso. Reflexiones sobre cómo participamos y nos posicionamos las mujeres en contextos de inseguridad social
En este foro reflexionamos sobre la situación de precariedad a la que nos enfrentamos las mujeres en Chile y en el mundo; la cual se vió acrecentada luego de los confinamientos forzados durante la pandemia por COVID 19. Frente a dichos contextos de inseguridad social, hemos desarrollado mecanismos alternativos de manifestación y resistencia a través del ciberactivismo. Las amenazas frente a la autonomía de las mujeres nunca desaparecen del todo y eso requiere que revisemos los marcos institucionales que permiten tales retrocesos cuando asumen el poder grupos conservadores o de extrema derecha
In-silico gene essentiality analysis of polyamine biosynthesis reveals APRT as a potential target in cancer
Constraint-based modeling for genome-scale metabolic networks has emerged in the last years as a promising approach to elucidate drug targets in cancer. Beyond the canonical biosynthetic routes to produce biomass, it is of key importance to focus on metabolic routes that sustain the proliferative capacity through the regulation of other biological means in order to improve in-silico gene essentiality analyses. Polyamines are polycations with central roles in cancer cell proliferation, through the regulation of transcription and translation among other things, but are typically neglected in in silico cancer metabolic models. In this study, we analysed essential genes for the biosynthesis of polyamines. Our analysis corroborates the importance of previously known regulators of the pathway, such as Adenosylmethionine Decarboxylase 1 (AMD1) and uncovers novel enzymes predicted to be relevant for polyamine homeostasis. We focused on Adenine phosphoribosyltransferase (APRT) and demonstrated the detrimental consequence of APRT gene silencing on diferent leukaemia cell lines. Our results highlight the importance of revisiting the metabolic models used for in-silico gene essentiality analyses in order to maximize the potential for drug target identifcation in cance
Frequent and simultaneous epigenetic inactivation of TP53 pathway genes in acute lymphoblastic leukemia
Aberrant DNA methylation is one of the most frequent alterations in patients with Acute Lymphoblastic Leukemia (ALL). Using methylation bead arrays we analyzed the methylation status of 807 genes implicated in cancer in a group of ALL samples at diagnosis (n = 48). We found that 154 genes were methylated in more than 10% of ALL samples. Interestingly, the expression of 13 genes implicated in the TP53 pathway was downregulated by hypermethylation. Direct or indirect activation of TP53 pathway with 5-aza-2'-deoxycitidine, Curcumin or Nutlin-3 induced an increase in apoptosis of ALL cells. The results obtained with the initial group of 48 patients was validated retrospectively in a second cohort of 200 newly diagnosed ALL patients. Methylation of at least 1 of the 13 genes implicated in the TP53 pathway was observed in 78% of the patients, which significantly correlated with a higher relapse (p = 0.001) and mortality (p<0.001) rate being an independent prognostic factor for disease-free survival (DFS) (p = 0.006) and overall survival (OS) (p = 0.005) in the multivariate analysis. All these findings indicate that TP53 pathway is altered by epigenetic mechanisms in the majority of ALL patients and correlates with prognosis. Treatments with compounds that may reverse the epigenetic abnormalities or activate directly the p53 pathway represent a new therapeutic alternative for patients with ALL
Problemática de las basuras marinas en España: el proyecto MARNOBA y la experiencia en la Demarcación marina del Estrecho y Alborán
Sobre la base de un programa piloto para caracterizar las basuras marinas de las playas de la Demarcación marina del Estrecho y Alborán, consistente en el muestreo representativo de las basuras marinas en 12 playas de la Demarcación a lo largo del año 2013, se ha elaborado y difundido un Protocolo de caracterización y gestión de las basuras marinas en las playas del litoral español con el objetivo de que constituya una herramienta de gestión de las basuras marinas en las playas y que como tal sea utilizado por asociaciones, organismos e instituciones que prevean realizar o realicen alguna actividad con respecto a dichas basuras, como las iniciativas populares de limpieza de playas, con el fin de que las mismas aporten información útil y contrastable para abordar de una manera global la problemática de las basuras marinas, tanto a nivel de sus fuentes, como de su gestión en tierra una vez retiradas. Además, se pretende que los datos recogidos se utilicen por los organismos públicos gestores del medio marino y costero en los programas de seguimiento de las basuras marinas en las playas, requeridos por la Directiva Marco sobre la Estrategia Marina y la Ley de protección del medio marino que el Ministerio de Agricultura, Alimentación y Medio Ambiente prevé aprobar en el año 2014, para evaluar la consecución del buen estado ambiental de las aguas marinas españolas
An in-silico approach to predict and exploit synthetic lethality in cancer metabolism
Exploiting synthetic lethality is a promising approach for cancer therapy. Here, the authors present an approach to identifying such interactions by finding genetic minimal cut sets (gMCSs) that block cancer proliferation, and apply it to study the lethality of RRM1 inhibition in multiple myeloma
Identifying Lethal Dependencies with HUGE Predictive Power
Recent functional genomic screens—such as CRISPR-Cas9 or RNAi screening—have fostered a new wave of targeted treatments based on the concept of synthetic lethality. These approaches identified LEthal Dependencies (LEDs) by estimating the effect of genetic events on cell viability. The multiple-hypothesis problem is related to a large number of gene knockouts limiting the statistical power of these studies. Here, we show that predictions of LEDs from functional screens can be dramatically improved by incorporating the “HUb effect in Genetic Essentiality” (HUGE) of gene alterations. We analyze three recent genome-wide loss-of-function screens—Project Score, CERES score and DEMETER score—identifying LEDs with 75 times larger statistical power than using state-of-the-art methods. Using acute myeloid leukemia, breast cancer, lung adenocarcinoma and colon adenocarcinoma as disease models, we validate that our predictions are enriched in a recent harmonized knowledge base of clinical interpretations of somatic genomic variants in cancer (AUROC > 0.87). Our approach is effective even in tumors with large genetic heterogeneity such as acute myeloid leukemia, where we identified LEDs not recalled by previous pipelines, including FLT3-mutant genotypes sensitive to FLT3 inhibitors. Interestingly, in-vitro validations confirm lethal dependencies of either NRAS or PTPN11 depending on the NRAS mutational status. HUGE will hopefully help discover novel genetic dependencies amenable for precision-targeted therapies in cancer. All the graphs showing lethal dependencies for the 19 tumor types analyzed can be visualized in an interactive tool
Synthesis and characterization of a luminescent cyclic poly(ethylene oxide)-polypyridyl ruthenium complex
We report the synthesis of a macrocyclic poly(ethylene oxide) (PEO) connected by one [Ru(bpy)3]2+ unit (where bpy = 2,2'-bipyridine), a photoactive metal complex that provides photosensitivity and potential biomedical applications to this polymer structure. The PEO chain provides biocompatibility, water solubility, and topological play. The macrocycles were successfully synthesized by copper-free click cycloaddition between a bifunctional dibenzocyclooctyne (DBCO)-PEO precursor and 4,4'-diazido-2,2'-bipyridine, followed by complexation with [Ru(bpy)2Cl2]. The cyclic product accumulated efficiently in MCF7 cancer cells and exhibited a longer fluorescence lifetime than its linear analogue, likely due to differences in the accessibility of the ligand-centered/intraligand states of Ru polypyridyls in both topologies.We acknowledge financial support from MCIN/AEI/10.13039/501100011033 and “ERDF A way of making Europe” (PID2021-123438NB-I00), the MICINN (PID2020-117766GB-I00), the Basque Government (Eusko Jaurlaritza grants IT1566-22 and PIBA 2021-1-0034), and Diputación Foral de Gipuzkoa (RED 2021:ID44). DIPC and IMDEA Nanociencia received support from the “Severo Ochoa” Programme for Centres of Excellence in R&D (MINECO, Grants CEX2018-000867-S and CEX2020-001039-S, respectively). L.S. thanks the Spanish Multi-MetDrugs network (RED2018-102471-T) for fruitful discussion.With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2018-000867-S and CEX2020-001039-S).Peer reviewe