High-precision indoor localisation is becoming a necessity with novel location-based services that are emerging around 5G. The deployment of high-precision indoor location technologies is usually ...costly due to the high density of reference points. In this work, we propose the opportunistic fusion of several different technologies, such as ultra-wide band (UWB) and WiFi fine-time measurement (FTM), in order to improve the performance of location. We also propose the use of fusion with cellular networks, such as LTE, to complement these technologies where the number of reference points is under-determined, increasing the availability of the location service. Maximum likelihood estimation (MLE) is presented to weight the different reference points to eliminate outliers, and several searching methods are presented and evaluated for the localisation algorithm. An experimental setup is used to validate the presented system, using UWB and WiFi FTM due to their incorporation in the latest flagship smartphones. It is shown that the use of multi-technology fusion in trilateration algorithm remarkably optimises the precise coverage area. In addition, it reduces the positioning error by over-determining the positioning problem. This technique reduces the costs of any network deployment oriented to location services, since a reduced number of reference points from each technology is required.
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The influence of temperature and chloride concentration on the corrosion behaviour of Mg–Al alloys exposed to salt fog was evaluated. Corrosion attack increased with decreasing aluminium content in ...the alloy and increasing Cl
− concentration and temperature. The effect of Al–Mn inclusions, which revealed several stoichiometries and were up to 300
mV more noble than the magnesium matrix, was only noticeable in the early stages of corrosion of the AZ31 alloy. Aluminium segregation and β-phase distribution were the main controlling factors for the AZ80 and AZ91D alloys, the latter being more susceptible to variations in the saline concentration.
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A shrimp tropomyosin (TPM) immunosensor has been developed and optimized to detect trace amounts of shrimp (in the ppm range), based on a combination of an amperometric transduction, magnetic ...particles and disposable screen-printed electrodes. The approach is based on the implementation of a sandwich immunoassay format on the surface of magnetic beads and their coupling onto disposable screen-printed electrodes to finally register the amperometric response at −200 mV vs. Ag pseudo-reference electrode, using H2O2 as enzymatic substrate and hydroquinone as redox mediator. The use of carboxyl-functionalized magnetic microbeads (MBs) and in-house made magnetic nanoparticles (MNPs) as solid supports have been evaluated and compared. Our experimental results confirm that the use of MBs, in addition to simplifying the test protocol, improves the resulting sensitivity, so they were selected for the implementation of the immunosensor. In the optimized experimental conditions, the developed immunosensor offered a LOD of 47 pg mL−1 for amperometric determination of shrimp TPM standards and great selectivity against TPM from other sources, thus allowing differentiation between crustaceans (shrimp) and mollusks (squid). Applicability studies demonstrated successful determination both in crude and cooked samples using very simple protocols. Additionally, processed foods based on fish and mollusks that could potentially include crustaceans in their composition have been analyzed using the sensor and compared to the declared ingredients.
The sensitivity and specificity showed by the sensor in the analysis of heterogeneous food samples without a previous purification or enrichment stage, also outperforms existing solutions in terms of time and cost effectiveness and permits its direct and smooth implementation in the food industry for routine allergen analyses.
Representation of the TPM sensor configuration and the reactions involved in the amperometric transduction at a screen-printed carbon electrode. Display omitted
•An amperometric immunosensor has been developed for the accurate detection of shrimp tropomyosin.•A limit of detection of 47 pg mL−1 has been obtained in under 3 h.•Crustacean and mollusk tropomyosin has been clearly differentiated, a relevant issue for the food processing industry.•The applicability of the sensor for the determination in both raw and cooked foods has been assessed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
4.
Victim Detection and Localization in Emergencies Álvarez-Merino, Carlos S.; Khatib, Emil J.; Luo-Chen, Hao Qiang ...
Sensors (Basel, Switzerland),
11/2022, Volume:
22, Issue:
21
Journal Article
Peer reviewed
Open access
Detecting and locating victims in emergency scenarios comprise one of the most powerful tools to save lives. Fast actions are crucial for victims because time is running against them. Radio devices ...are currently omnipresent within the physical proximity of most people and allow locating buried victims in catastrophic scenarios. In this work, we present the benefits of using WiFi Fine Time Measurement (FTM), Ultra-Wide Band (UWB), and fusion technologies to locate victims under rubble. Integrating WiFi FTM and UWB in a drone may cover vast areas in a short time. Moreover, the detection capacity of WiFi and UWB for finding individuals is also compared. These findings are then used to propose a method for detecting and locating victims in disaster scenarios.
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•An electrochemical immuno-biochip for TNFα biomarker has been developed.•Integration of fluidics and sensing parts in a disposable design.•A detection limit of 4.1 ng/mL has been ...achieved.•Successful determination in human serum has been demonstrated.
This paper presents a disposable microfluidic electrochemical immunosensor for rapid, cheap and quantitative detection of biomarkers. Dual screen-printed carbon electrodes were biofunctionalized with specific antibodies and subsequently encapsulated with an all-disposable polymeric microfluidic cell. The electrochemical detection was carried out by means of differential pulse voltammetry (DPV) using a portable potentiostat. One of the two working electrodes was employed as an on-chip integrated negative control. The system was optimized and characterized for the detection of tumor necrosis factor alpha (TNFα), an important inflammation biomarker, with a limit of detection (LOD) of 4.1 ng/mL. Successful experiments in real human serum were also carried out.
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Anthropization of insular ecosystems may have negative impacts on native populations of lizards, which provide core ecosystem services on islands. We aimed to identify environmental factors to ...explain the interlocal variation in faecal glucocorticoids, parasite intensity, and body condition in populations of insular lizards. A cross-sectional design during the summer of 2017 and 2018 was used to sample 611 adult lizards, Gallotia galloti. Interlocal variation of three stress indicators was analysed in response to environmental variables across a wide environmental gradient in Tenerife (Canary Islands): (i) concentration of faecal glucocorticoids, (ii) intensities of infection by hematic parasites, and (iii) body condition. The data, with low spatial autocorrelation, were analysed using multimodel inference and model cross-validation. Bioclimatic variables associated with the extreme hot and dry climate of summer were the most informative predictors. Interlocal variation in faecal corticosterone in males was best fitted to a model that included the maximum temperature of the warmest month, although the best predictor was habitat anthropization. The thermal annual range, associated with extreme thermal events, was positively related to faecal corticosterone in females. Extreme hot temperatures were positively related to the median parasite intensities in both sexes, while the highest mean intensities of infection were found in females from the most xeric coastal localities. None of the predictors tested, including faecal glucocorticoids, explained individual or interlocal variation in body condition. Effects of human pressure and climate change on insular populations of lizards can be additive. However, the uncoupled relationship found between body condition and the faecal glucocorticoid content suggests that current negative effects may be aggravated during drought periods in summer. Given the impact of climate change on islands, our results may be of application to other archipelagos, where lizards also play key ecological roles.
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•The impact of anthropization on insular lizards is scarcely known.•Three health/stress indicators were analysed along an environmental gradient.•Corticosterone and hematic parasites co-vary with human development and climate.•Environmental impacts are different for males and females.•Monitoring lizard populations in islands may allow anticipating cascading effects.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A high-precision location is becoming a necessity in the future Industry 4.0 applications that will come up in the near future. However, the construction sector remains particularly obsolete in the ...adoption of Industry 4.0 applications. In this work, we study the accuracy and penetration capacity of two technologies that are expected to deal with future high-precision location services, such as ultra-wide band (UWB) and WiFi fine time measurement (FTM). For this, a measurement campaign has been performed in a construction environment, where UWB and WiFi-FTM setups have been deployed. The performance of UWB and WiFi-FTM have been compared with a prior set of indoors measurements. UWB seems to provide better ranging estimation in LOS conditions but it seems cancelled by reinforcement concrete for propagation and WiFi is able to take advantage of holes in the structure to provide location services. Moreover, the impact of fusion of location technologies has been assessed to measure the potential improvements in the construction scenario.
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Climate change effects on host–parasite interactions have been poorly studied in arid or semi-arid habitats. Here, we conducted an experiment aimed to increase the temperature inside European roller ...Coracias garrulus nest boxes located in a semi-arid habitat on different nest-site types to look for effects on different ectoparasite abundances and nestling growth. Average nest temperature was slightly higher in heated nests than in control nests, although differences were not statistically significant. However, relative humidity was significantly lower at night in heated nests as compared to control nests. The abundance of sand flies, mites and carnid flies was significantly higher in heated, less humid, nests while biting midge abundance was significantly lower in heated nests. Other ectoparasites were not significantly affected by treatment. Relative humidity was high even in heated nests, reaching more than 60%. Sand fly abundance was higher in nests located in sandstone walls, while mite abundance was higher in isolated farmhouses. In addition, sand fly prevalence was higher in nests located in isolated farmhouses and sandstone walls. Heat treatment, nest-site type or ectoparasite abundances did not affect the nestling body mass, wing length or their growth at different nestling ages.
A highly sensitive amperometric magnetoimmunosensor for the determination of ErbB2 protein, a well-known biomarker related to high-impact high-incidence diseases such as breast cancer, is described. ...A sandwich format involving the covalent immobilization of a specific capture antibody onto magnetic beads (MBs) and incubation of the modified MBs with a mixture solution of the antigen and a HRP-labeled detector antibody was used. The resulting modified MBs were captured on the surface of a disposable screen-printed carbon electrode (SPCE) and the amperometric responses at −0.20V were measured. This ErbB2 magnetoimmunosensor exhibited a very low detection limit of 26pgmL−1 far below the established cut-off for this biomarker (15ngmL−1) and was successfully applied to the quantitation of ErbB2 in human serum and cell lysates samples without any matrix effect. In addition, the developed assay allowed the assessment of ErbB2 status directly in intact breast cancer cells. The results correlated well with those obtained with a commercial ELISA method, thus demonstrating that the new magnetoimmunosensing platform offers a truthful and useful analytical tool to be easily applied in breast cancer diagnosis through either ErbB2 protein determination or breast cancer cell status detection.
Amperometric magnetoimmunosensor for the determination of ErbB2 protein in human serum and cells lysates and for the assessment of ErbB2 status in breast cancer cells.
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•Sensitive amperometric magnetoimmunosensor for ErbB2 protein.•Detection limit of 26pgmL−1.•Successful determination in human serum and cell lysates samples.•Assessment of ErbB2 status in intact breast cancer cells.•Potential applications in cancer research and clinical diagnosis.
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•Electrochemical magnetoimmunosensor for tumor necrosis factor alpha (TNFα) biomarker.•Sensitive and selective detection of TNFα in undiluted serum.•LOD achieved lower than the ...cut-off value established for relevant illnesses.•Useful and affordable alternative to ELISAs for TNFα determination in serum.
An amperometric immunoassay for the determination of tumor necrosis factor alpha (TNFα) protein biomarker in human serum based on the use of magnetic microbeads (MBs) and disposable screen-printed carbon electrodes (SPCEs) has been developed. The specifically modified microbeads were magnetically captured on the working electrode surface and the amperometric responses were measured at −0.20V (vs. Ag pseudo-reference electrode), upon addition of hydroquinone (HQ) as electron transfer mediator and H2O2 as the enzyme substrate. After a thorough optimization of the assay, extremely low limits of detection were achieved: 2.0pgmL−1 (36fM) and 5.8pgmL−1 (105fM) for standard solutions and spiked human serum, respectively. The simplicity, robustness and this clinically interesting LOD proved the developed TNFα immunoassay as a good contender for real clinical application.
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