Browsing by Keyword "Biochemistry"
Now showing 1 - 20 of 93
Results Per Page
Sort Options
Item 3D convolutional neural networks initialized from pretrained 2D convolutional neural networks for classification of industrial parts(2021-02-04) Merino, Ibon; Azpiazu, Jon; Remazeilles, Anthony; Sierra, Basilio; ROBOTICA_FLEX; Medical TechnologiesDeep learning methods have been successfully applied to image processing, mainly using 2D vision sensors. Recently, the rise of depth cameras and other similar 3D sensors has opened the field for new perception techniques. Nevertheless, 3D convolutional neural networks perform slightly worse than other 3D deep learning methods, and even worse than their 2D version. In this paper, we propose to improve 3D deep learning results by transferring the pretrained weights learned in 2D networks to their corresponding 3D version. Using an industrial object recognition context, we have analyzed different combinations of 3D convolutional networks (VGG16, ResNet, Inception ResNet, and EfficientNet), comparing the recognition accuracy. The highest accuracy is obtained with EfficientNetB0 using extrusion with an accuracy of 0.9217, which gives comparable results to state-of-the art methods. We also observed that the transfer approach enabled to improve the accuracy of the Inception ResNet 3D version up to 18% with respect to the score of the 3D approach alone.Item Analysing Edge Computing Devices for the Deployment of Embedded AI(2023-12) Garcia-Perez, Asier; Miñón, Raúl; Torre-Bastida, Ana I.; Zulueta-Guerrero, Ekaitz; HPAIn recent years, more and more devices are connected to the network, generating an overwhelming amount of data. This term that is booming today is known as the Internet of Things. In order to deal with these data close to the source, the term Edge Computing arises. The main objective is to address the limitations of cloud processing and satisfy the growing demand for applications and services that require low latency, greater efficiency and real-time response capabilities. Furthermore, it is essential to underscore the intrinsic connection between artificial intelligence and edge computing within the context of our study. This integral relationship not only addresses the challenges posed by data proliferation but also propels a transformative wave of innovation, shaping a new era of data processing capabilities at the network’s edge. Edge devices can perform real-time data analysis and make autonomous decisions without relying on constant connectivity to the cloud. This article aims at analysing and comparing Edge Computing devices when artificial intelligence algorithms are deployed on them. To this end, a detailed experiment involving various edge devices, models and metrics is conducted. In addition, we will observe how artificial intelligence accelerators such as Tensor Processing Unit behave. This analysis seeks to respond to the choice of a device that best suits the necessary AI requirements. As a summary, in general terms, the Jetson Nano provides the best performance when only CPU is used. Nevertheless the utilisation of a TPU drastically enhances the results.Item Analysis of the Refined Mean-Field Approximation for the 802.11 Protocol Model(2022-11) Ispizua, Begoña; Doncel, Josu; IAMean-field approximation is a method to investigate the behavior of stochastic models formed by a large number of interacting objects. A new approximation was recently established, i.e., the refined mean-field approximation, and its high accuracy when the number of objects is small has been shown. In this work, we consider the model of the 802.11 protocol, which is a discrete-time model and show how the refined mean-field approximation can be adapted to this model. Our results confirm the accuracy of the refined mean-field approximation when the model with N objects is in discrete time.Item Attrition-resistant membranes for fluidized-bed membrane reactors: Double-skin membranes: Double-skin membranes(2018-10-01) Arratibel, Alba; Medrano, Jose Antonio; Melendez, Jon; Pacheco Tanaka, D. Alfredo; van Sint Annaland, Martin; Gallucci, Fausto; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOS; Tecnalia Research & InnovationPd-Ag supported membranes have been prepared by coating a ceramic interdiffusion barrier onto a Hastelloy X (0.2 µm media grade) porous support followed by deposition of the hydrogen selective Pd-Ag (4–5 µm) layer by electroless plating. To one of the membranes an additional porous Al2O3-YSZ layer (protective layer with 50 wt% of YSZ) was deposited by dip-coating followed by calcination at 550 °C on top of the Pd-Ag layer, and this membrane is referred to as a double-skin membrane. Both membranes were integrated at the same time in a single reactor in order to assess and compare the performance of both membranes under identical conditions. The membranes have first been tested in an empty reactor with pure gases (H2 and N2) and afterwards in the presence of a catalyst (rhodium onto promoted alumina) fluidized in the bubbling regime. The membranes immersed in the bubbling bed were tested at 400 °C and 500 °C for 115 and 500 h, respectively. The effect of the protective layer on the permeation properties and stability of the membranes were studied. The double-skinned membraned showed a H2 permeance of 1.55·10−6 mol m−2 s−1 Pa−1 at 500 °C and 4 bar of pressure difference with an ideal perm-selectivity virtually infinite before incorporation of particles. This selectivity did not decay during the long term test under fluidization with catalyst particles.Item Biosensing strategies based on enzymatic reactions and nanoparticles(2018-04-21) Díez-Buitrago, Beatriz; Briz, Nerea; Liz-Marzán, Luis M.; Pavlov, Valeri; Tecnalia Research & Innovation; SGEnzymes are pivotal elements in bioanalysis due to their specificity and extremely high catalytic activity. The sensitivity of bioanalytical assays depends mainly on the capacity of an observer to detect the product(s) of a biocatalytic reaction. Both natural and artificial compounds have been traditionally used to evaluate enzymatic activities. The drawbacks of chromogenic and fluorogenic organic enzymatic substrates are their high cost and low stability, resulting in high background signals. We review here state of the art assays in the detection of enzymatic activities using recent advances in nanoscience. Novel methods based on the use of nanoparticles lead to increased sensitivity and decreased costs for bioanalysis based on enzymes as recognition elements and signal amplifiers in Enzyme-Linked Immunosorbent Assays (ELISA). Novel approaches toward the detection of enzymatic activities are based on biocatalytic synthesis, modulation, etching, and aggregation of nanoparticles under physiological conditions.Item Can Shared Control Improve Overtaking Performance? Combining Human and Automation Strengths for a Safer Maneuver(2022-12) Marcano, Mauricio; Tango, Fabio; Sarabia, Joseba; Chiesa, Silvia; Pérez, Joshué; Díaz, Sergio; CCAMThe Shared Control (SC) cooperation scheme, where the driver and automated driving system control the vehicle together, has been gaining attention through the years as a promising option to improve road safety. As a result, advanced interaction methods can be investigated to enhance user experience, acceptance, and trust. Under this perspective, not only the development of algorithms and system applications are needed, but it is also essential to evaluate the system with real drivers, assess its impact on road safety, and understand how drivers accept and are willing to use this technology. In this sense, the contribution of this work is to conduct an experimental study to evaluate if a previously developed shared control system can improve overtaking performance on roads with oncoming traffic. The evaluation is performed in a Driver-in-the-Loop (DiL) simulator with 13 real drivers. The system based on SC is compared against a vehicle with conventional SAE-L2 functionalities. The evaluation includes both objective and subjective assessments. Results show that SC proved to be the best solution for assisting the driver during overtaking in terms of safety and acceptance. The SC’s longer and smoother control transitions provide benefits to cooperative driving. The System Usability Scale (SUS) and the System Acceptance Scale (SAS) questionnaire show that the SC system was perceived as better in terms of usability, usefulness, and satisfaction.Item Carbon molecular sieve membranes for water separation in CO2 hydrogenation reactions: Effect of the carbonization temperature(2023-07-05) Poto, Serena; Aguirre, A.; Huigh, F.; Llosa-Tanco, Margot Anabell; Pacheco-Tanaka, David Alfredo; Gallucci, Fausto; Neira d'Angelo, M. Fernanda; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSCarbon membranes are a potentially attractive candidate for the in-situ removal of water vapor in CO2 hydrogenation reactions. Their hydrophilicity and pore structure can be tuned by properly adjusting the synthesis procedure. Herein, we assess the effect of the carbonization temperature (450–750 °C) on the performance of supported CMSM in terms of vapor/gas separation, in correlation with changes in their surface functionality and porous structure. FTIR spectra showed that the nature of the functional groups changes with the evolution of the carbonization step, leading to a gradual loss in hydrophilicity (i.e., OH stretching disappears at Tcarb ≥ 600 °C). The extent of water adsorption displays an optimum at Tcarb of 500 °C, with the membrane carbonized at 650 °C being the least hydrophilic. We found that the pore size distribution strongly influences the water permeance. At all Tcarb, adsorption-diffusion (AD) is the dominant transport mechanisms. However, as soon as ultra-micropores appear (Tcarb: 600–700 °C) molecular sieving (MS) contributes to an increase in the water permeance, despites a loss in hydrophilicity. At Tcarb ≥ 750 °C, MS pores disappear, causing a drop in the water permeance. Finally, the permeance of different gases (N2, H2, CO, CO2) is mostly affected by the pore size distribution, with MS being the dominant mechanism over the AD, except for CO2. However, the extent and mechanism of gas permeation drastically change as a function of the water content in the feed, indicating that gas/vapor molecules need to compete to access the pores of the membranes.Item CHANGES IN OSTEOGENESIS BY HUMAN DENTAL PULP STEM CELLS ON PORCINE DECELLULARISED ADIPOSE TISSUE SOLID FOAMS OF DIFFERENT POROSITY(2023-07-01) Luzuriaga, Jon; García-Urkia, Nerea; Salvador-Moya, Jone; Pardo-Rodríguez, Beatriz; Etxebarria, Iker; Fernandez-San-Argimiro, Francisco Javier; Olalde, Beatriz; Unda, Fernando; Pineda, Jose Ramon; Madarieta, Iratxe; Ibarretxe, Gaskon; BiomaterialesThe extracellular matrix of white adipose tissue (AT) is a very promising biomaterial for tissue engineering, due to its abundance, easy accessibility, malleability, and proven biological activity. Decellularised AT (DAT) can be processed by freeze-drying in acetic acid solutions, and changing the DAT concentration in the solution gives rise to three-dimensional (3D) scaffolds of different stiffness and porosity. In a previous report, we demonstrated that human Dental Pulp Stem Cells (hDPSCs) could differentiate to osteoblasts and generate mineralised bone on 3D solid foams of porcine Decellularised Adipose Tissue (pDAT) at a concentration of 0.5 % (w/v). In this research work, we assessed whether and how osteogenesis by hDPSCs would be regulated by testing pDAT solid foams formulated at three different concentrations: 0.25 % (w/v), 0.5 % (w/v), and 1 % (w/v), which showed different stiffness, porosity and water retention properties. As a control condition we tested solid foams formulated with 0.5 % bovine Collagen-I. Thus, we performed Alkaline Phosphatase and Alizarin Red staining, together with Transmission Electron Microscopy and the detection of osteoblastic differentiation markers Osterix and Osteocalcin at both protein and transcript level, to compare the osteogenesis mediated by hDPSCs grown on all these 3D scaffolds, in the presence or absence of osteoblastic induction media. Our results demonstrate that pDAT at 0.25 % supported osteogenesis better than the rest of tested scaffolds, including bovine Collagen-I, in 3D hDPSC cultures. This enhanced osteogenesis could be attributed to the formulation of 0.25 % pDAT solid foams, which presented a higher porosity.Item Chemoselective epoxidation of dienes using polymer-supported manganese porphyrin catalysts(2004-07-05) Brulé, Emile; De Miguel, Yolanda R.; Hii, King Kuok; MercadoManganese porphyrin catalysts supported on different polymer resins were assessed in the selective epoxidation of three dienes. The recyclability of the catalysts was examined.Item Chlorosulfonation of polystyrene substrates for bioanalytical assays: Distribution of activated groups at the surface(2012) Del Prado, Anselmo; Briz, Nerea; Navarro, Rodrigo; Pérez, Mónica; Gallardo, Alberto; Reinecke, Helmut; SGIn this work the activation of transparent PS substrates by chlorosulfonation is described and their distribution in the subsurface region is analyzed. For this purpose XPS, FTIR-ATR and colorimetry have been used. It is shown that the electrophilic aromatic substitution of polystyrene in pure chlorosulfonic acid is extremely quick with complete surface coverage by chlorosulfonic groups achieved after only a 10 minute reaction time at -10 °C. It is further demonstrated that the reaction is very surface selective and that even after reaction times as long as 3 hours, the modification is limited to a layer with a thickness of less than one micron. The activated PS substrates can be further functionalized in a second step with carboxylic groups. Due to the excellent optical transparency that the samples maintain upon modification, the modified systems were successfully probed for use in ELISA assays.Item Collaboration-Centred Cities through Urban Apps Based on Open and User-Generated Data(2016-07-01) Aguilera, Unai; López-de-Ipiña, Diego; Pérez-Velasco, Jorge; Tecnalia Research & InnovationThis paper describes the IES Cities platform conceived to streamline the development of urban apps that combine heterogeneous datasets provided by diverse entities, namely, government, citizens, sensor infrastructure and other information data sources. This work pursues the challenge of achieving effective citizen collaboration by empowering them to prosume urban data across time. Particularly, this paper focuses on the query mapper; a key component of the IES Cities platform devised to democratize the development of open data-based mobile urban apps. This component allows developers not only to use available data, but also to contribute to existing datasets with the execution of SQL sentences. In addition, the component allows developers to create ad hoc storages for their applications, publishable as new datasets accessible by other consumers. As multiple users could be contributing and using a dataset, our solution also provides a data level permission mechanism to control how the platform manages the access to its datasets. We have evaluated the advantages brought forward by IES Cities from the developers' perspective by describing an exemplary urban app created on top of it. In addition, we include an evaluation of the main functionalities of the query mapper.Item A Complete Framework for a Behavioral Planner with Automated Vehicles: A Car-Sharing Fleet Relocation Approach(2022-11) Arizala, Asier; Zubizarreta, Asier; Pérez, Joshué; CCAMCurrently, research on automated vehicles is strongly related to technological advances to achieve a safe, more comfortable driving process in different circumstances. The main achievements are focused mainly on highway and interurban scenarios. The urban environment remains a complex scenario due to the number of decisions to be made in a restrictive context. In this context, one of the main challenges is the automation of the relocation process of car-sharing in urban areas, where the management of the platooning and automatic parking and de-parking maneuvers needs a solution from the decision point of view. In this work, a novel behavioral planner framework based on a Finite State Machine (FSM) is proposed for car-sharing applications in urban environments. The approach considers four basic maneuvers: platoon following, parking, de-parking, and platoon joining. In addition, a basic V2V communication protocol is proposed to manage the platoon. Maneuver execution is achieved by implementing both classical (i.e., PID) and Model-based Predictive Control (i.e., MPC) for the longitudinal and lateral control problems. The proposed behavioral planner was implemented in an urban scenario with several vehicles using the Carla Simulator, demonstrating that the proposed planner can be helpful to solve the car-sharing fleet relocation problem in cities.Item Continuous quantitative risk management in smart grids using attack defense trees(2020-08-07) Rios, Erkuden; Rego, Angel; Iturbe, Eider; Higuero, Marivi; Larrucea, Xabier; CIBERSEC&DLT; Tecnalia Research & InnovationAlthough the risk assessment discipline has been studied from long ago as a means to support security investment decision-making, no holistic approach exists to continuously and quantitatively analyze cyber risks in scenarios where attacks and defenses may target different parts of Internet of Things (IoT)-based smart grid systems. In this paper, we propose a comprehensive methodology that enables informed decisions on security protection for smart grid systems by the continuous assessment of cyber risks. The solution is based on the use of attack defense trees modelled on the system and computation of the proposed risk attributes that enables an assessment of the system risks by propagating the risk attributes in the tree nodes. The method allows system risk sensitivity analyses to be performed with respect to different attack and defense scenarios, and optimizes security strategies with respect to risk minimization. The methodology proposes the use of standard security and privacy defense taxonomies from internationally recognized security control families, such as the NIST SP 800-53, which facilitates security certifications. Finally, the paper describes the validation of the methodology carried out in a real smart building energy efficiency application that combines multiple components deployed in cloud and IoT resources. The scenario demonstrates the feasibility of the method to not only perform initial quantitative estimations of system risks but also to continuously keep the risk assessment up to date according to the system conditions during operation.Item Correlating gas permeability and morphology of bio-based polyether-block-amide copolymer membranes by IR nanospectroscopy(2024-08) David, Oana; Etxeberria Benavides, Miren; Amenabar Altuna, Iban; Fernandez Carretero, Francisco Jose; Diaz De Guereñu Zabarte, Maria del Mar; Flat, Jean Jaques; Pineau, Quentin; Goikoetxea Larruskain, Monika; Hillenbrand, Rainer; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOS; TECNOLOGÍAS DE HIDRÓGENOThe gas permeability of polymer membranes is determined by their nanoscale morphology, which strongly depends on the membrane fabrication. Here, we demonstrate how the correlation between gas permeability and fabrication-dependent nanoscale morphology of polymer membranes can be elucidated by infrared (IR) nanospectroscopy based on elastic IR scattering at an atomic force microscope tip. Specifically, we fabricated membranes of PEBAX® RNEW – a bio-based polyether-block-amide copolymer – by solvent casting and extrusion, achieving unprecedented CO2 permeability and CO2/N2 selectivity for the solvent-cast membranes. For the extruded membranes, however, we found an about 50 % reduced CO2 permeability, which could not be explained by differential scanning calorimetry and conventional IR spectroscopy. In contrast, IR nanospectroscopy revealed a highly crystalline polyether oxide (PEO) surface layer on the extruded membranes, not observed for the solvent-cast membranes. Annealing of the extruded membranes at 110 °C transformed the crystalline into amorphous PEO layers, as confirmed by IR nanospectroscopy, yielding a gas permeability close to that of the solvent-cast membranes. We thus attribute the dramatic gas reduction of the extruded membranes to their highly crystalline surface layers. Generally, studying polymer morphology by IR nanospectroscopy provides valuable information for better understanding the local gas permeability properties of polymer membranes.Item Decellularization of bovine corneas for tissue engineering applications(2009-07) Ponce Márquez, Sara; Martínez, Virginia Sáez; McIntosh Ambrose, Winnette; Wang, Jennie; Gantxegui, Nerea Garagorri; Schein, Oliver; Elisseeff, Jennifer; Tecnalia Research & InnovationScaffolds derived from processed tissues offer viable alternatives to synthetic polymers as biological scaffolds for regenerative medicine. Tissue-derived scaffolds provide an extracellular matrix (ECM) as the starting material for wound healing and the functional reconstruction of tissues, offering a potentially valuable approach for the replacement of damaged or missing tissues. Additionally, acellular tissue may provide a natural microenvironment for host-cell migration and the induction of stem cell differentiation to contribute to tissue regeneration. There are a number of processing methods that aim to stabilize and provide an immunologically inert tissue scaffold. Furthermore, these tissue-processing methods can often be applied to xenogenic transplants because the essential components of the ECM are often maintained between species. In this study, we applied several tissue-processing protocols to the cornea in order to obtain a decellularized cornea matrix that maintained the clarity and mechanical properties of the native tissue. Histology, mechanical testing and electron microscopy techniques were used to assess the cell extraction process and the organization of the remaining ECM. In vitro cell seeding experiments confirmed the processed corneas' biocompatibility.Item Design of a photoelectrochemical lab-on-a-chip immunosensor based on enzymatic production of quantum dots in situ(2022-04-22) Díez-Buitrago, Beatriz; Fernández-San Argimiro, Francisco Javier; Lorenzo, Jaione; Bijelic, Goran; Briz, Nerea; Pavlov, Valeri; Tecnalia Research & Innovation; Biomateriales; Mercado; SGIn this work we report the development and validation of a photoelectrochemical immunosensor on the basis of alkaline phosphatase (ALP)-linked immunoassay for the detection of human serum albumin as a model analyte. In this biosensor, oriented immobilization of capture antibodies on aminated polystyrene was achieved via physical adsorption. After the interaction with the analyte, ALP immobilised on the surface through the sandwich immunoassay catalyses the hydrolysis of sodium thiophosphate (TP) to hydrogen sulphide (H2S) which in the presence of cadmium ions yields CdS quantum dots (QDs). The electrical current is generated in the course of the photoelectrochemical process (PEC) during irradiation of the CdS QDs with a UV LED (365 nm) on home-made screen-printed carbon electrodes modified with a conductive polymer. Reaction time, steps and volumes were optimized for the miniaturization of the process in order to develop a lab-on-a-chip platform. The microfluidic system was designed with optimised parameters to fabricate the immunosensor combining the immunoassay with PEC detection. The final system presents a sensitivity comparable to that of the commercial kit thanks to the signal amplification enabled by the enzymatic growth of CdS QDs in situ. This photoelectrochemical immunosensing strategy potentially opens up a new avenue for the detection of a wide range of analytes of interest due to the universal and effective enzymatic signal amplification method. Moreover, the developed bioanalytical device allows for a great reduction of time and reagents compared to exiting commercial assays, making it suitable for point-of-care applications.Item Development of Coated PLA Films Containing a Commercial Olive Leaf Extract for the Food Packaging Sector(2024-05) Fiorentini, Cecilia; Leni, Giulia; de Apodaca, Elena Díaz; Fernández-de-Castro, Laura; Rocchetti, Gabriele; Cortimiglia, Claudia; Spigno, Giorgia; Bassani, Andrea; Alimentación SostenibleA commercial olive leaf extract (OL), effective against Salmonella enterica, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus, was added to three different coating formulations (methylcellulose, MC; chitosan, CT; and alginate, ALG) to produce active polylactic acid (PLA) coated films. Evaluation of these coated PLA films revealed significant inhibition of S. aureus growth, particularly with the MC and CT formulations exhibiting the highest inhibition rates (99.7%). The coated films were then tested for food contact compatibility with three food simulants (A: 10% ethanol; B: 3% acetic acid; D2: olive oil), selected to assess their suitability for pre-cut hams and ready-to-eat vegetables in relation to overall migration. However, coated films with active functions exhibited migration values in simulants A and B above legal limits, while promising results were obtained for simulant D2, highlighting the need to deeply investigate these coatings’ impact on a real food system. Untargeted metabolomics revealed that the type of coating influenced the selective release of certain phenolic classes based on the food simulant tested. The Oxitest analysis of simulant D2 demonstrated that the MC and ALG-coated PLA films slightly slowed down the oxidation of this food simulant, which is an edible vegetable oil.Item Development of Pd-based double-skinned membranes for hydrogen production in fluidized bed membrane reactors(2018-03-15) Arratibel, Alba; Pacheco Tanaka, Alfredo; Laso, Iker; van Sint Annaland, Martin; Gallucci, Fausto; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSThis paper reports the preparation and performance characterization of new PdAg supported membranes with a porous protecting layer to protect the membrane surface from particles in a fluidized bed membrane reactor. Supported membranes with a selective layer of 1 µm and a protective layer have been prepared. Outstanding H2 permeance (5·10−6 mol m−2 s−1 Pa−1) and H2/N2 perm-selectivity (over 25,000) were measured at 400 °C and 1 bar of pressure difference. One membrane has been tested for more than 750 h in the presence of fluidized glass beads showing a decay in the perm-selectivity to approximately 5000, mainly due to sealing leakage. However, the protective layer was removed during this long-term test. Another membrane has been tested for more than 2000 h in a fluidized bed membrane reactor with a Rh reforming catalyst supported on promoted alumina in the bubbling fluidization regime. During tests with binary mixtures mass transfer limitations toward the membrane were observed due to large H2 permeance of the membranes.Item Differences in Drug-Susceptibility Patterns between Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium chimaera Clinical Isolates: Prospective 8.5-Year Analysis by Three Laboratories(2023-01) Fernandez-Pittol, Mariana; Batista-Arnau, Sara; Román, Angely; San Nicolás, Lorena; Oliver, Laura; González-Moreno, Olga; Martínez, José Antonio; Amaro-Rodríguez, Rosanel; Soler, Néstor; Gené, Amadeu; González-Cuevas, Araceli; Tudó, Griselda; Gonzalez-Martin, Julian; ADAPTACIÓN AL CAMBIO CLIMÁTICOBackground: It has been suggested that Mycobacterium avium, Mycobacterium intracellulare, and M. chimaera have differential drug susceptibility patterns. We prospectively analyzed and compared the drug susceptibility patterns among these species over an 8.5-year period. Methods: A microdilution method (Slomyco®) was performed for drug susceptibility testing of 402 M. avium, 273 M. intracellulare, and 139 M. chimaera clinical isolates. Results: M. avium showed significantly higher resistance to moxifloxacin, ciprofloxacin, rifampicin, ethambutol, streptomycin, linezolid, cotrimoxazole, and clarithromycin. M. avium also showed higher minimum inhibitory concentrations (MIC) than M. intracellulare and M. chimaera against all drugs except ethionamide, to which M. intracellulare and M. chimaera showed greater resistance. Conclusions: Our series demonstrated differential drug resistance patterns among the most frequent M. avium complex species. M. avium was more resistant than M. intracellulare and M. chimaera versus eight antibiotics and showed greater MIC values to most of the antibiotics studied. These data suggest that knowledge of the local distribution and susceptibility profiles of these pathogens is essential for adequate clinical management.Item Differential expression of oxidative stress and inflammation related genes in peripheral blood mononuclear cells in response to a low-calorie diet: A nutrigenomics study(2008-12-01) Crujeiras, Ana B.; Parra, Dolores; Milagro, Fermín I.; Goyenechea, Estibaliz; Larrarte, Eider; Margareto, Javier; Martínez, J. Alfredo; Generales; GenéticaNutrigenomics is a new application of omics technologies in nutritional science. Nutrigenomics aims to identify molecular markers of diet-related diseases and mechanisms of interindividual variability in response to food. The aim of this study was to evaluate peripheral blood mononuclear cells (PBMC) as a model system and readily available source of RNA to discern gene expression signatures in relation to personalized therapy of obesity. PBMC were collected from obese men before and after an 8-week low-calorie diet (LCD) to lose weight. Changes in gene expression before and after the LCD were initially screened using a DNA-microarray platform and validated by qRT-PCR. Global gene expression analysis identified 385 differentially expressed transcripts after the LCD. Further analyses showed a decrease in some specific oxidative stress and inflammation genes. Interestingly, expression of these genes was directly related to body weight, while a lower IL8 gene expression was associated with higher fat mass decrease. Collectively, these observations suggest that PBMCs are a suitable RNA source and model system to perform nutrigenomics studies related to obesity and development of personalized dietary treatments. IL8 gene expression warrant further research as a putative novel biomarker of changes in body fat percentage in response to an LCD.