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Jimenez-Leon J.,National Institute of Astrophysics, Optics and Electronics | Sarmiento-Reyes A.,National Institute of Astrophysics, Optics and Electronics | De La Cruz Blas C.A.,UPNA | Gomez-Polo C.,UPNA
2017 International Caribbean Conference on Devices, Circuits and Systems, ICCDCS 2017 | Year: 2017

Fabricated Ag/TiO2/ITO devices, that show memristive properties, have been measured and their electrical variables were characterized. A piecewise nonlinear methodology is used to recast the model of the device in a range-dependent polynomial. The resulting model is coded in a high-level hardware description language with the aim of incorporating the device into a simulation framework. © 2017 IEEE.

Aguirre E.,UPNA | Arpon J.,UPNA | Azpilicueta L.,UPNA | de Migue S.,Health Institute Carlos III | And 2 more authors.
Progress In Electromagnetics Research B | Year: 2012

In this work, the influence of human body within the estimation of dosimetric values is analyzed. A simplified human body model, including the dispersive nature of material parameters of internal organs, skin, muscle, bones and other elements has been implemented. Such a model has been included within an indoor scenario in which an in-house 3D ray launching code has been applied to estimate received power levels within the complete scenario. The results enhance previous dosimetric estimations, while giving insight on influence of human body model in power level distribution and enabling to analyze the impact in the complete volume of the scenario.

Sobron A.,IMEC | Romero I.,IMEC | Romero I.,HIGH-TECH | Lopetegi T.,UPNA
Computing in Cardiology | Year: 2010

A comparative study of methods for estimating respiratory frequency through electrocardiogram was carried out. Methods were based on beat morphology (QRS area or amplitude) and heart rate variability. In addition a combination of methods was also investigated. For each method, time and frequency correlation between the ECG derived respiration and the real respiration recorded by chest plethysmography were computed as well as the relative error in the respiration rate. Results indicate that combining the spectra of different methods gives overall the best estimation of the respiration rate. This technique obtained a median relative error of 1.07% (mad=22.13) in free breathing signals. Methods based on Area, Amplitude and AMEA had relative errors around 1.10% (17/18). HRV however, had high relative errors in free breathing signals (42.70% (24.26)).

News Article | January 25, 2016
Site: www.techtimes.com

Spanish engineers developed new humidity sensors to fight bacteria production in highly humid environments. Across various industries, humidity is one of the most monitored and controlled operations aspects. But there are still many problems that threaten the monitoring and controlling processes, especially in environments with very high levels of humidity. Bacteria multiply in environments where with the humidity levels are very high. This results in the "biofilm" formations, which are ecosystems of microorganisms that are typically attached to a surface. Biofilm formations on surfaces lead to material deteriorations, which often affect the devices, including its performance and service lifetime. The deterioration process due to biofilm formation is known as biological fouling or "biofouling," which refers to the buildup of microorganism on wet surfaces. "Right now, the costs arising out of biofouling are very high mainly because of the maintenance work or replacement of equipment," said engineer Aitor Urrutia from Spain's Universidad Pablica de Navarra (UPNA). Urrutia and team developed novel humidity sensors with antibacterial properties for devices that work in high humidity environments. These new humidity sensors prevent biofilm creation and help solve biofouling. Using a combination of nanotechnology and latest developments in fiber optic, the new humidity sensors have improved performance and longer service lifetimes. The humidity sensor has an optical structure that is coated with silver nanoparticles. The coating is less than one micron thick. The humidity sensors are biocompatible and immune to electromagnetic interference. They are also inexpensive, compact and lightweight. The new humidity sensors can be utilized in various industries, including food processing, biotechnology, pharmaceutical industry, home automation, health clinics and hospital. It could help in monitoring human respiration among others. Since the sensors are compact and lightweight, they can be used to monitor humidity levels in areas that have limited access. "Thanks to the embedded silver nanoparticles included, these coatings provide the sensors with two additional functionalities: antibacterial properties and increased sensitivity," said Urrutia. Department of Electrical and Electronic Engineering lecturers Javier Goicoechea-Fernández and Francisco J. Arregui-San Martín supervised Urrutia's PhD thesis. The study was published in the journal Nanoscale Research Letters on Dec. 29, 2015.

News Article | October 25, 2016
Site: phys.org

Research by the NUP/UPNA-Public University of Navarre has proposed various designs for photonic crystal materials that can be used to filter radiation. Specifically, the focus has been to develop a coating comprising dielectric spheres that, applied to a window, would prevent outside heat from entering in the summer and the indoor heat from escaping in winter.

The industrial engineer Iñaki Cornago-Santos has developed structures on a nanometric scale that can be used as biosensors for medical, food or environmental sectors to detect diseases, allergens or contaminants; or can be used to reduce the reflection of solar cells in order to increase their efficiency. This is what he says in his PhD thesis defended at the NUP/UPNA-Public University of Navarre.

News Article | February 24, 2017
Site: www.eurekalert.org

The first of these sensors provides information without being in contact with the plant and works by capturing information in terahertz, one of the ranges in the electromagnetic spectrum located between microwaves (that a mobile phone or TV need to function) and infrared waves. "These devices transmit a signal in terahertz and measure what proportion of the signal is returned by the trunk of the vine," explained Gonzaga Santesteban-García, lecturer in the Department of Agricultural Production and leader of the research project. "It involves reflectance technology without any contact with the plant. That way, we can check the plant's water status. It is a technique that has not been used before for this purpose". The results of this development have been published in the journals "Frontiers in Plant Science" and "Journal of Infrared, Millimeter and Terahertz Waves". The researchers have simplified the design of the sensor because a large bandwidth is not needed; it uses planar technology, which allows a high degree of miniaturization and thus considerably cuts the cost per unit, since many of its chips can be obtained commercially at a low price. The second of the sensors developed is based on a totally different principle. In this case, the aim was to use magnetoelastic sensors to detect the changes that take place throughout the day and night in the size of the trunk or branches of the vine, in other words, they indicate how the vine is growing. Gonzaga-Santiesteban explained that sensors of this type offer two advantages over the classical dendrometers used by some wineries. "Firstly, this is a different technology enabling costs to be reduced and, secondly, we have made it more flexible so that these devices can be fitted not only to the trunk, as until now, but also to different parts of the vine, such as, for example, the cluster," he added. The results of this development have also been partially published in the journal "IEEE Transactions on Magnetics". The development of these devices comes within the framework of the European VITICS Project that had total funding of almost 564,000 euros, co-funded by the European Regional Development Fund and the Government of Navarre. The following NUP/UPNA research groups have participated in this project: Advanced Fruit Farming and Wine Growing, responsible for coordinating the work; Antennas; Physical Properties and Applications of Materials; and Communication, Signals and Microwaves. They also had the collaboration of the following companies: Bodegas Ochoa (in Olite), Enonatura (in Villatuerta) and Cima-NTI (in Huarte-Pamplona).

News Article | February 21, 2017
Site: www.eurekalert.org

This is one of the conclusions of the PhD thesis, read at the NUP/UPNA-Public University of Navarre by the medical doctor Patricia Serra-Arbeloa, who conducted a cost-effectiveness study on a diagnostic test carried out on patients with cutaneous melanoma: the selective biopsy of the sentinel ganglion. Lymphatic ganglions, small glands spread throughout the body, are an important part of the immune system and help to determine whether the cancer cells have acquired the capacity to spread to other parts of the body. A sentinel lymph gland is defined as the first to which cancer cells are more likely to spread from a primary tumour (the first that appears in the body). The biopsy of the sentinel lymph ganglion is a procedure in which one or more ganglions are located, removed and examined to see whether there are any cancer cells. This biopsy is normally used to help to determine the status of two types of cancer: breast cancer and cutaneous melanoma. Patricia Serra's PhD thesis focussed on evaluating the selective biopsy of the sentinel ganglion in skin cancer, "a technique widely used in managing cutaneous melanoma and whose effectiveness and costs have not been assessed despite the fact that the results of the clinical trials published are conflicting," said the researcher. "Following a systematic review in which nearly 3,000 scientific articles on this subject were studied, it was found that countless works had been published but only a fraction presented a high level of scientific evidence," pointed out the new PhD holder. Particia Serra also confirmed that the use of this biopsy "does not offer significant differences in global survival in cases of cutaneous melanoma with thicknesses in the intermediate and thick ranges with respect to the other strategy: the mere monitoring of the patient after the removal of the initial lesion, which appears 'ex novo' and which is regarded as a minimum treatment". "In thin melanomas it is not possible to establish conclusions with respect to survival, although the tendency is similar to that described for other thicknesses," she added. In the cost-effectiveness analysis, this biopsy "does not show an improvement in health outcomes in terms of years of life gained and years of life gained adjusted to quality in these patients, except for a slight benefit in cutaneous melanoma with an intermediate thickness". "To this is added the fact that the high costs in diagnosing cutaneous melanoma at an advanced stage point to the need to promote primary prevention and early detection programmes," pointed out Patricia Serra. For all these reasons the author of the research concluded that selective biopsy of the sentinel ganglion in cutaneous melanoma "does not have a positive cost-effectiveness ratio with respect to the technique of removing the primary tumour followed by the monitoring of the patient, irrespective of the thickness of the tumour and timeframe".

News Article | January 23, 2016
Site: www.nanotech-now.com

Home > Press > New sensors to combat the proliferation of bacteria in very high-humidity environments Abstract: The engineer Aitor Urrutia has received his PhD with these devices that combine nanotechnology and fibre optics for use in hospitals or on industrial premises. The Telecommunications Engineer Aitor Urrutia-Azcona has designed some humidity sensors with anti-bacterial properties that combat the proliferation of micro-organisms in environments where the humidity level is very high, such as hospitals and industrial premises for foodstuffs or pharmaceutical products. These devices combining nanotechnology and fibre optics are part of his PhD thesis read at the Public University of Navarre (NUP/UPNA). “Humidity is one of the most controlled and most monitored aspects nowadays owing to its great importance in a whole range of industrial processes or in areas such as food monitoring, air quality, biomedicine or chemistry,” explained Aitor Urrutia, who is from Auritz/Burguete, but who currently resides in Irúñea-Pamplona. “Yet problems remain in terms of measuring and monitoring it in specific situations such as environments where the humidity level is very high”. The proliferation of bacteria in such environments where the humidity is very high is common and this leads to the formation of “biofilms” which are ecosystems made up of these microorganisms attached to a surface. This leads to the problem known as biofouling which causes “the deterioration of many materials and devices, affects their performance and cuts their service lifetimes. Right now, the costs arising out of biofouling are very high mainly because of the maintenance work or replacement of equipment,” pointed out Urrutia. When considering this widespread problem, in his PhD thesis Aitor Urrutia set about building new humidity sensors that would have antibacterial properties for applications that function in environments where the humidity is high and which are conducive to bacterial growth, and thus prevent the creation of biofilms and overcome biofouling. Combining nanotechnology and fibre optics To develop the various humidity sensors, Aitor Urrutia based himself on the combination of the latest advances in nanotechnology (new materials and new manufacturing techniques for coatings and nanoparticles) over new fibre optic configurations. “The sensors developed are made up of an optic structure to which coatings with a thickness of less than one micron are applied,” pointed out the new PhD holder. “Thanks to the embedded silver nanoparticles included, these coatings provide the sensors with two additional functionalities: antibacterial properties and increased sensitivity. That way, the new sensors developed have longer service lifetimes and perform better”. What is more, these fibre optic sensors offer additional advantages such as “their biocompatibility, immunity with respect to electromagnetic interference, their low cost, size and weight, and the possibility of long-distance measuring,” according to Urrutia, whose PhD thesis was supervised by the lecturers in the Department of Electrical and Electronic Engineering Francisco J. Arregui-San Martín and Javier Goicoechea-Fernández. The new humidity sensors developed could be integrated into a wide variety of sectors, such as, for example, health centres and hospitals to monitor human respiration, among other applications; on premises and in chambers used in processes in the foodstuff and pharmaceutical industry; in biotechnology and home automation; and in the monitoring of structures or cavities that are difficult to access, such as cooling towers or off-shore facilities. Full bibliographic information P. J. Rivero, A. Urrutia, J. Goicoechea, F. J. Arregui, (2015) "Nanomaterials for functional textiles and fibers," Nanoscale Research Letters 10 (1) 501: 1-2,. doi:10.1186/s11671-015-1195-6 About Elhuyar Fundazioa Elhuyar Fundazioa is a Science and Technology Foundation. Its first mission is to make science accessible to ordinary people and work with our language euskara. Within our product we have dictionaries, University books, web-pages, journals, radio programs and TV programs. For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Ximena Carrión Granda, a Food Engineering graduate from Ecuador, has developed edible coatings containing natural substances with antimicrobial properties in order to extend the shelf-life of fish and seafood products by two to four days due to the reduction of the growth rate of the spoilage microorganisms. This work was developed at the Department of Food Technology of the Public University of Navarre (UPNA) as part of her doctoral thesis. "The edible films and coatings are fine, and continuous layers of edible material placed on food surfaces or separating different phases of a food system to increase product quality, extend the shelf-life or improve food safety", Carrión Granda explains. Her doctoral thesis was supervised by Professor Juan I. Maté Caballero (UPNA) and Professor Jordi Rovira Carballido (University of Burgos). These coatings create "a barrier between the product and the surrounding atmosphere. This way, the food is protected, preventing humidity loss, reducing fat oxidation, controlling discolouration and preserving food quality and properties," Ximena Carrión says. "In addition, the edible coatings can act as carriers of additives such as antioxidants, mineral salts or antimicrobial agents that could reduce the growth of microorganisms on product surfaces". Research on edible coatings has undergone considerable impulse over the last few years, given the changes in the lifestyle of consumers, who demand "fresh products with minimal processing and no synthetic additives that can last as long as possible and are convenient to prepare". The food industry requires emerging technologies to increase food shelf life and offer safe products. This is the case with fish and seafood, given their dietary importance (only in 2014 in Spain, 554,000 tonnes of fresh fish were consumed), being "an excellent source of proteins, vitamins, minerals and polyunsaturated fats. Nevertheless, they are extremely perishable products, even more than red meat or chicken, due to their high surface humidity and free amino acid content. The spoilage process begins with loss of texture and the production of putrid odours basically caused by the development of microorganisms", Ximena Carrión points out. Hence, the edible antimicrobial coatings are considered "an emerging technology suitable for controlling the microbiological deterioration of fish and seafood". Ximena Carrión developed edible films and coatings based on whey protein isolate and chitosan, a polysaccharide extracted from chitin, a structural element found in the shells of crustaceans (crabs, shrimps and lobsters). Using these, she formed coatings that were "insoluble and colourless", to which she added "different antimicrobial agents that are gradually released on the fish and seafood surfaces, reducing the growth rate at which deteriorating microorganisms grow, therefore extending the shelf-life". Since the food market currently tends towards the consumption of food without synthetic preservatives, she used natural substances with antimicrobial properties, such as essential oils (from thyme and rosemary), plant extracts (from sage, oregano, garlic and rosemary) and lactic acid bacteria (L. plantarum, L. lactis and W. confusa). These compounds were combined at different concentrations into whey protein and chitosan films and their antimicrobial activity was assessed against fourteen bacterial strains related to the spoilage and pathogenicity of fish and seafood. "The best formulations were used to assess the effect on microbial development in fresh tuna and hake fillets and peeled shrimp tails, packaged with and without air –using modified atmosphere– and stored in refrigeration for different periods of time", the new doctor explained. Her results showed that the films containing oregano and thyme essential oils and the extract of rosemary yielded the greatest antimicrobial effect in vitro against pathogenic bacteria (A. hydrophila, L. monocytogenes or S. Typhimurium) and deteriorating bacteria (V. alginolyticus or S. putrefaciens). On application to the different types of fish and seafood, the edible coatings were effective in retarding microbial growth and increasing the shelf-life of the treated products by two to four days. Moreover, the films containing lactic acid bacteria were successfully evaluated in vitro against L. monocytogenes.

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